¿Estamos ganando terreno sobre la infección ocular?

<div dir="ltr" style="text-align: left;" trbidi="on"> Visualización optima 1600x900 pixel Comenta.esta.publicación<br /> Para Publicaciones en otros idiomas te invitamos a utilizar el traductor incorporado en infolentes<br /> <br /> <br /> <h5 style="background-color: #fefefd; font-family: Tahoma, Arial, Helvetica; font-size: 13px; margin: 0px 0px 10px; padding: 0px;"> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><span class="">Las fluoroquinolonas tópicas de nueva generación son algunos de los antibióticos más eficaces que he visto nunca. </span>Pero, aumento de la resistencia bactericida sigue siendo una preocupación.</span></h5> <span style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: 12px;">Por Elizabeth D. Muckley, OD 12/17/2012</span><br /> <span style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: 12px;"><br /></span> <div style="text-align: justify;"> </div> <div class="MsoNormal"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";">Sin embargo, todas las fluoroquinolonas de nueva generación se utilizan fuera de las indicaciones para numerosas condiciones de queratitis ulcerativa en la prevención de infecciones en la atención pre-y post-quirúrgicos.<span class="apple-converted-space"> </span>Mirando hacia atrás en los últimos 20 años, debemos preguntarnos si estos medicamentos están cumpliendo con su promesa y lo que será el futuro de la gestión de la infección ocular y la prevención como aspecto?<span class="apple-converted-space"> </span>En cualquier caso, nuestra mayor preocupación en el futuro es el desarrollo de nuevos patrones de resistencia a las fluoroquinolonas tópicas.<span class="apple-converted-space"> <o:p></o:p></span></span></div> <div class="MsoNormal"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";"><span class="apple-converted-space"><br /></span></span></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKgXrk1he8uc_HPWIfpt_Dd-oLpW8JdYerN1oXPQt2U4mI5_p6G_94TgisApCPZzrguOCRT0gMYF6QCvY-UaazcE0XvKVsTcXGgj12pPNMTqLJodPdoJorciLk7mMqe30tMCaFftFV-ro/s1600/038_ro1212_f2-1.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKgXrk1he8uc_HPWIfpt_Dd-oLpW8JdYerN1oXPQt2U4mI5_p6G_94TgisApCPZzrguOCRT0gMYF6QCvY-UaazcE0XvKVsTcXGgj12pPNMTqLJodPdoJorciLk7mMqe30tMCaFftFV-ro/s400/038_ro1212_f2-1.gif" width="400" /></a></div> <div class="separator" style="clear: both; text-align: center;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <strong style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; text-align: start;">Este paciente se presentó con un pronunciado <em>Pseudomonas</em> úlcera. ¿Cuál es la estrategia de tratamiento más eficaz?</strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; text-align: start;"><br /></strong></div> <div class="separator" style="clear: both; text-align: center;"> </div> <div class="MsoNormal" style="text-align: justify;"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";">Sin embargo, todas las fluoroquinolonas de nueva generación se utilizan fuera de las indicaciones para numerosas condiciones de queratitis ulcerativa en la prevención de infecciones en la atención pre-y post-quirúrgicos.<span class="apple-converted-space"> </span>Mirando hacia atrás en los últimos 20 años, debemos preguntarnos si estos medicamentos están cumpliendo con su promesa y lo que será el futuro de la gestión de la infección ocular y la prevención como aspecto?<span class="apple-converted-space"> </span>En cualquier caso, nuestra mayor preocupación en el futuro es el desarrollo de nuevos patrones de resistencia a las fluoroquinolonas tópicas.<span class="apple-converted-space"> </span></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";"><span class="apple-converted-space"><br /></span></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";"><span class="apple-converted-space"></span></span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;"><strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><span style="color: brown;">Mechanism of Action</span></strong> <br style="font-family: Tahoma, Arial, Helvetica, sans-serif;" />Topical fluoroquinolones are antibiotic agents that block bacterial DNA synthesis by inhibiting the topoisomerase enzymes. Older-generation topical fluoroquinolones (ciprofloxacin, ofloxacin and levofloxacin) specifically target the DNA enzyme topoisomerase IV, which is more susceptible in gram-negative bacteria.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">1,2</sup> However, the fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) contain a substitution of a methoxy group at position eight of the quinolone ring, which additionally facilitates topoisomerase II (DNA gyrase) inhibition in gram-positive organisms. </span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;">This dual mechanism of action promotes increased bactericidal activity against gram-positive organisms without sacrificing the gram-negative coverage provided by older-generation fluoroquinolones.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">3</sup> Most importantly, targeting both topoisomerase II and IV likely reduces resistance because concomitant mutations in both genes are much less likely to occur than a single mutation in one gene.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">4,5</sup> </span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;"><strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><span style="color: brown;">Drug Penetration and Tissue Concentration</span></strong> <br style="font-family: Tahoma, Arial, Helvetica, sans-serif;" />For topical fluoroquinolones to be effective in the treatment of ocular infections, they must exhibit satisfactory minimum inhibitory concentration (MIC) scores, high penetration rates into ocular tissues/aqueous and broad susceptibility profiles, as well as posess the ability to thwart resistance. </span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;">The MIC is defined as the lowest possible concentration of an antibiotic that is able to prevent overnight micro-organism growth in a tissue culture. Typically, MIC90 (the MIC score required to inhibit bacterial growth in at least 90% of targeted strains) is the standard measure of bactericidal efficacy for topical anti-infective agents. Note that the lower the MIC90 value, the more potent the agent is against a given isolate.</span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;">The ocular surface poses a challenge to drug administration and pharmacokinetics. Tears act as a drug-delivery barrier, effectively diluting the agent and facilitating drainage via the nasolacrimal system upon rapid blinking following instillation.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">6</sup> Therefore, MIC scores derived from in vitro laboratory testing may not accurately reflect on-eye MIC values. Delivering the drug to the target tissue, as well as remaining there long enough to be effective in vivo, is of equal importance. Compared to their systemic counterparts, topical antibiotics often must be dosed at higher concentrations to increase drug penetration and sustain effective therapeutic levels. </span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;">The fourth-generation fluoroquinolones offer the best penetration profile; in particular, moxifloxacin and 1.5% levofloxacin fared well in corneal penetration studies.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">7-9, 15-18</sup></span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <span style="font-family: Arial;"><sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><br /></sup></span></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> <table bgcolor="#F0C2CC" bordercolor="" cellpadding="" cellspacing="" style="border-collapse: collapse; border: 0px; color: #333333; font-size: 12px; height: 444px; margin: 10px; text-align: center; width: 494px;"><tbody> <tr><td colspan="5" style="padding: 3px; text-align: center;" valign="top"><span style="font-size: small;"><strong>Commonly Prescribed Topical Fluoroquinolones</strong></span> </td></tr> <tr><td style="padding: 3px; text-align: center;"><em><span style="font-family: Arial; font-size: x-small;">Generic Name</span></em></td><td style="padding: 3px; text-align: center;"><em><span style="font-family: Arial; font-size: x-small;">Brand Name and Approval Date</span></em></td><td style="padding: 3px; text-align: center;"><em><span style="font-family: Arial; font-size: x-small;">Manufacturer</span></em></td><td style="padding: 3px; text-align: center;"><em><span style="font-family: Arial; font-size: x-small;">Classification</span></em></td><td style="padding: 3px; text-align: center;" valign="middle"><em><span style="font-family: Arial; font-size: x-small;">Indication</span></em></td></tr> <tr><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">0.3% Ciprofloxacin</span></td><td style="padding: 3px;"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Ciloxan, </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">December 1990</span></div> </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">Alcon, generic </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">2nd Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">0.3% Ofloxacin </span></td><td style="padding: 3px;"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Ocuflox, </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">July 1993  </span></div> </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">Allergan, generic </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">2nd Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">0.5% Levofloxacin </span></td><td style="padding: 3px;"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Quixin, </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">August 2000</span></div> </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">Vistakon</span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">3rd Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">0.3% Gatifloxacin</span></td><td style="padding: 3px;"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Zymar, </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">March 2003  </span></div> </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">Allergan </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">4th Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">0.5% Moxifloxacin</span></td><td style="padding: 3px;"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Vigamox, </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">April 2003  </span></div> </span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">Alcon</span></td><td style="padding: 3px; text-align: center;"><span style="font-family: Arial; font-size: x-small;">4th Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">1.5% Levofloxacin </span></td><td style="padding: 3px;" valign="top"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Iquix,</span><span style="background-color: transparent; font-size: x-small;"> </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">March 2004</span></div> </span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Vistakon</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">3rd Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Corneal Ulcers</span></td></tr> <tr><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">0.6% Besifloxacin</span></td><td style="padding: 3px;" valign="top"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Besivance,</span><span style="background-color: transparent; font-size: x-small;"> </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">May 2009 </span></div> </span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bausch + Lomb</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Novel (no systemic equivalent)</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">0.5% Gatifloxacin</span></td><td style="padding: 3px;" valign="top"><div style="text-align: center;"> <span style="background-color: transparent; font-family: Arial; font-size: x-small;">Zymaxid,</span><span style="background-color: transparent; font-size: x-small;"> </span></div> <span style="font-family: Arial; font-size: x-small;"><div style="text-align: center;"> <span style="background-color: transparent;">May 2010</span></div> </span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Allergan</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">4th Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> <tr><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">0.5% Moxifloxacin</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Moxeza,<span style="font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: x-small;"> </span>November 2010 </span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Alcon</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">4th Generation</span></td><td style="padding: 3px; text-align: center;" valign="top"><span style="font-family: Arial; font-size: x-small;">Bacterial Conjunctivitis</span></td></tr> </tbody></table> </div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: justify;"> <strong style="background-color: #fefefd; color: #333333;"><span style="color: brown; font-size: small;">Drug Enhancements</span></strong></div> <div style="font-family: Tahoma, Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: -webkit-left;"> </div> <div style="text-align: justify;"> <span style="background-color: #fefefd; color: #333333; font-family: Arial;">In an effort to amplify antibiotic concentration on the ocular surface and improve penetration, many ocular pharmaceutical companies developed enhanced or reformulated versions of existing fluoroquinolones during the last eight years. For example, Vistakon released Iquix in 2004, which contained more than double the concentration of levofloxacin in Quixin.</span><sup style="color: #333333;">10</sup><span style="background-color: #fefefd; color: #333333; font-family: Arial;">Also, in May 2010, Allergan brought Zymaxid to the market, which contained 0.2% more gatifloxacin than Zymar.</span><sup style="color: #333333;">11 </sup></div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px;"> </div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Then, in November 2010, Alcon released Moxeza as a successor to Vigamox. In this instance, the concentration of moxifloxacin was not increased. Instead, the company reformulated Vigamox with a new delivery vehicle, xanthan gum. In clinical trials, the xanthan gum facilitated increased corneal penetration of moxifloxacin. Most significantly, the increased drug penetration of Moxeza permitted b.i.d. dosing vs. t.i.d. dosing for Vigamox.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">12</sup></span></div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Bausch + Lomb’s release of Besivance (besifloxacin) in 2009 was a significant development in ocular antibiotics. Besifloxacin was developed for the sole purpose of ophthalmic use, and has no systemic counterpart.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">13</sup> This unique aspect could potentially help minimize resistance to the drug over the long term. The drug features a unique chlorine group located at position eight of the quinolone ring, as well as an aminoazepinyl component at the C-7 location, which may enhance activity against gram-positive bacteria.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">14</sup> </span></div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Additionally, Besivance uses the DuraSite vehicle (InSite Vision), which prolongs the drug’s contact time on the ocular surface and enhances corneal penetration. Finally, it is important to note that Besivance just received an additional FDA indication for the treatment of conjunctivitis associated with <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Pseudomonas aeruginosa</em> in September 2012.</span></div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px;"> </div> <div style="text-align: justify;"> <strong><span style="color: brown;">The Effect of BAK </span></strong></div> <span style="font-family: Arial;"><div style="text-align: justify;"> For many years, researchers have debated the potential benefits and limitations of the preservative benzalkonium chloride (BAK) in topical antibiotics. In topical medications that are commonly used long-term, such as glaucoma agents, the presence of BAK has been shown to cause ocular surface inflammation and corneal damage.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">15</sup>However, it has been suggested that, because BAK disrupts the ocular surface, it actually may enhance corneal penetration of the drug. Furthermore, BAK has been shown to increase epithelial permeability and trans-scleral drug delivery.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">16</sup> Currently, Vigamox, Moxeza and Iquix are the few topical fluoroquinolones that do not contain BAK.</div> </span><br /> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Interestingly, some studies indicated that BAK-preserved Zymar is more effective at targeting methicillin-resistant<em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Staphylococcus aureus</em> (MRSA) than BAK-free Vigamox in vitro.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">17</sup> Other in vitro research suggested that, while BAK may enhance an antibiotic’s effect, it is cleared by the tears rapidly.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">18</sup> More specifically, the study author noted that the concentration of BAK in the tears is undetectable five minutes after installation.18</span></div> <div style="background-color: #fefefd; color: #333333; margin-bottom: 12px; text-align: justify;"> </div> <div style="margin-bottom: 12px; text-align: -webkit-left;"> </div> <div style="text-align: justify;"> <strong><span style="color: brown;">Bactericidal Resistance</span></strong><span style="font-family: Arial;"> </span></div> <span style="font-family: Arial;"><div style="text-align: justify;"> In addition to corneal penetration, pharmacodynamics (e.g., kill rates, resistance patterns and susceptibility profiles) is another crucial aspect of topical fluoroquinolones. Studies suggest that MICs for fourth-generation fluoroquinolones are lower (better) than second-generation fluoroquinolones for all gram-positive organisms.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">19,20</sup>The MIC90 for ciprofloxacin was lower in gram-negative bacteria compared to the newer-generation fluoroquinolones, and was the most effective against <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Pseudomonas</em> among all topical fluoroquinolones tested.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">19,20</sup> </div> </span><br /> <div style="margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Bactericidal resistance is a result of many factors, including overprescribing and negligent prescribing of antibiotics (e.g., errant use of antibiotics for a viral condition), improper dosing (including patient non-compliance), and widespread use of antibiotics in the livestock industry. Infection by drug-resistant organisms such as MRSA and methicillin-resistant <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Staphylococcus epidermidis</em> (MRSE) is a growing concern in the ophthalmic community. According to the Centers for Disease Control and Prevention, 1.5% of the population (4 million Americans) are MRSA carriers.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">21</sup> Patients in nursing care facilities, health care workers, and those who live in communities where skin-to-skin contact is prevalent are at higher risk for MRSA infections.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">21</sup></span></div> <div style="margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) study was designed to monitor antibiotic susceptibility trends in ocular isolates.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">22</sup> The results indicated that 39% of <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">S. aureus</em> ocular isolates were methicillin resistant and 38% were fluoroquinolone resistant. Among the coagulase-negative staphylococci isolates sampled from ocular infections, 53% were methicillin resistant and 43% were fluoroquinolone resistant.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">22</sup> This is similar to the original data collected by The Surveillance Network (TSN) from 2001 to 2006, which revealed multidrug-resistant MRSA in ocular isolates.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">23</sup> Of interest, TSN researchers noted that trimethoprim was the most effective agent against MRSA.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">23 </sup></span></div> <div style="margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">Currently, the Ocular Tracking Resistance in the United States Today (TRUST) program is the largest annual, longitudinal, nationwide surveillance of antibiotic resistance. Since the program’s launch in 2005, Ocular TRUST researchers have evaluated the in vitro susceptibility of <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Staph.</em>, <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Strep.</em>, and <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Haemophilus</em> ocular isolates to numerous antibiotics.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">24</sup> The most recent data from Ocular TRUST suggests that just 15% to 30% of MRSA isolates are susceptible to currently available topical fluoroquinolones (Besivance was not evaluated, because it was not yet FDA approved at study initiation).<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">24 </sup></span></div> <div style="margin-bottom: 12px; text-align: justify;"> <span style="font-family: Arial;">The combined results from ARMOR, TSN and Ocular TRUST show that resistance to multiple antibiotics is prevalent among ocular bacterial pathogens. Again, keep in mind that in vitro resistance does not necessarily equate to in vivo resistance. Still, eye care clinicians must consider the potential danger associated with such expanding resistance patterns.</span></div> <br /> <br /> <br /> <br /> <div class="MsoNormal" style="text-align: justify;"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";"><span class="apple-converted-space"><table align="center" bgcolor="#F0C2CC" bordercolor="" cellpadding="" cellspacing="" style="border-collapse: collapse; border: 0px; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: 12px; margin: 10px;"><tbody> <tr><td style="padding: 3px;"><strong>Recommendations for Fluoroquinolone Use</strong></td></tr> <tr><td style="padding: 3px;"><div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>Don’t underdose an active infection. </em></strong>Antibiotics with the lowest MIC values and the highest delivery concentration are best suited to eradicate ocular infections. For active infections, dose antibiotics at their recommended frequency to eliminate the bacteria quickly. The greatest risk for the development of antibiotic resistance comes from sustained sub-therapeutic dosing, which doesn’t eradicate the infection but potentially affords it time to mutate. </span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>Be judicious in prophylactic use. </strong></em>When used for surgical prophylaxis, antibiotics can be discontinued sooner than in cases of active infection. A recent study found that repeated fluoroquinolone use after intravitreal injection led to increased rates of resistance.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">30</sup> So, instead of using prophylactic antibiotics, many retinal specialists now are using facemasks and iodine/aseptic techniques during injection to minimize the risks of infection. For infection prevention in cataract surgery, good wound architecture is critical. Today, with femtosecond laser-assisted surgery, wound leaks and consequent endophthalmitis risks may be less likely.</span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>Avoid overprescribing. </em></strong>Improper diagnosis of red eye is a specific instance when topical antibiotics frequently are overprescribed. Too often, pediatricians, urgent care physicians and even optometrists/ophthalmologists prescribe antibiotics for conditions other than bacterial conjunctivitis, when the diagnosis is not clear. Overprescribing propagates bactericidal resistance, so exercise good clinical judgment when using an antibiotic. </span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>Choose an appropriate antibiotic. </em></strong>Consider reserving a “big gun” antibiotic, such as a fourth-generation fluoroquinolone, for the most serious infectious cases. Second-generation fluoroquinolones, aminoglycosides or azithromycin (Azasite, Merck) are alternative antibiotic choices for infections that are not sight threatening. Such alternatives may be effective, and choosing them could potentially limit fourth-generation antibiotic resistance. Also, review the FDA drug safety classification for children and pregnant patients. For example, Azasite may be a good choice for pregnant or nursing mothers because it is a Category B drug.</span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>When in doubt, culture.</em></strong> Smears and cultures are recommended in cases that involve a large infiltrate (>3mm); are chronic in nature or appear unresponsive to broad-spectrum antibiotic therapy; or that exhibit atypical clinical features indicative of fungal, amoebic or <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Mycobacterium</em> keratitis. The sensitivities from cultures can help guide appropriate antibiotic selection.</span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">In cases of suspected bacterial keratitis, fourth-generation fluoroquinolones routinely are used off-label and are widely accepted as first-line therapy. Depending on its location and severity, microbial keratitis can be a sight-threatening condition. For central or severe keratitis, a loading dose (q15m for the first hour) followed by frequent applications (q1h around the clock) is recommended. </span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">For drug-resistant pathogens, such as MRSA or MRSE, fluoroquinolones may not prove effective. If a bacterial infection is not clinically responsive to aggressive treatment with a fluoroquinolone, suspect MRSA/MRSE. Consider treatment with fortified vancomycin, trimethoprim or sulfacetamide.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">31</sup> In these instances, be certain to obtain cultures in an effort to select the most effective antibiotic. Additional therapeutic options that may be effective against MRSA/MRSE include bacitracin ointment, cefazolin injection and oral linezolid. Concurrent use of oral rifampin and linezolid have been shown to be more effective in the treatment of preseptal cellulitis/cutaneous infections than intravenous vancomycin.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">32 </sup></span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>Be wary of </em>Mycobacterium<em>. </em></strong>Regarding refractive surgery, infection rates fortunately are low. But, if an infection occurs, atypical <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Mycobacterium</em> infiltrates may be of greatest concern. Although rare, <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Mycobacterium</em>are found in ultrasound water baths used for instrument processing or in surgical field moisture. In any confirmed case of <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Mycobacterium</em> <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">chelonae</em> infection, researchers at Johns Hopkins recommend 500mg clarithromycin b.i.d., topical tobramycin and a fourth-generation fluoroquinolone.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">33 </sup></span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">• <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><em>Consider the cost. </em></strong>Because of rising medication prices, patients are sometimes forced to use generic antibiotics in lieu of branded medications. Newer-generation fluoroquinolones have the broadest antimicrobial spectrum. But, if patients cannot afford these, which generic agent is best? To date, no studies offer a real solution to this question, and practitioners are faced with the ongoing dilemma of cost vs. efficacy. </span></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">However, generic trimethoprim-polymyxin B should be considered when there is a risk of MRSA. Despite being an older drug, more than 90% of MRSA isolates were susceptible to trimethoprim in vitro.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">28</sup> Also, the second-generation fluoroquinolones are cost effective, and have a broad spectrum of coverage. They are a good choice if a generic is needed. Regardless, educate patients about the potential risks associated with having to choose between the lower cost of generic medications and the therapeutic superiority of branded drugs.</span></div> </td></tr> </tbody></table> </span></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="background: #FEFEFD; color: #333333; font-family: "Tahoma","sans-serif";"><span class="apple-converted-space"></span></span></div> <div id="content_container" style="font-family: Tahoma, Arial, Helvetica, sans-serif; position: relative; text-align: -webkit-left;"> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;"><span style="color: brown; font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong><span style="font-size: small;">Use in Surgical Prophylaxis</span></strong></span> <br style="font-family: Tahoma, Arial, Helvetica, sans-serif;" />Topical antibiotics are used routinely for infection prevention in all forms of ocular surgery. The discussion about appropriate use of prophylactic antibiotics is a hot topic among eye care professionals due to increased resistance patterns. Some studies have reported increased endophthalmitis rates since 2000 despite prophylactic antibiotic use.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">25</sup></span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">There are several possible reasons why endophthalmitis is on the rise. For example, more surgeons perform cataract surgery using sutureless, clear corneal incisions, which are more prone to leakage. Additionally, intravitreal anti-VEGF and steroidal injections are being administered more frequently for the treatment of macular degeneration and diabetic eye disease. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">Most cases of postoperative endophthalmitis are due to <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">S. epidermidis</em>, followed by <em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">S. aureus</em>.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">26</sup> Further, epidemiologic evidence suggests that MRSA is responsible for approximately 3% of all endophthalmitis cases.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">26 </sup></span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">The overall rate of endophthalmitis after uncomplicated cataract surgery in patients who received prophylactic treatment with gatifloxacin and moxifloxacin was 0.07%.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">26</sup> Another study found a similar endophthalmitis rate for those who received gatifloxacin and moxifloxacin (0.056%), but a higher incidence in patients who were treated with ciprofloxacin and ofloxacin (0.197%).<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">27</sup></span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">These data suggest that the fourth-generation fluoroquinolones are more effective against gram-positive organisms and may be the superior choice for surgical endophthalmitis prevention. Fortunately, the risk of post-surgical infection is extremely rare. And ultimately, the low rates of endophthalmitis also make it exceedingly difficult to compare the prophylactic efficacy of different antibiotics exhaustively.</span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">During the last few years, intracameral antibiotics have been evaluated for use in ocular surgery. A recent study by the European Society of Cataract & Refractive Surgeons (ESCRS) showed that cefuroxime injection can reduce endophthalmitis risk in cataract surgery.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">28</sup> Further, intracameral injections have the potential to help reduce postoperative patient noncompliance/drop confusion, and could be more cost effective than topical anti-infective use. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">The primary barrier to wider adoption of intracameral antibiotic administration in the United States is the lack of a commercially available drug. Cefuroxime, for example, must be compounded manually, which exposes the patient to bacterial contamination and toxic anterior segment syndrome. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">In lieu of cefuroxime, some American cataract surgeons are using intracameral administration of moxifloxacin and vancomycin to reduce or eliminate postoperative antibiotic drops.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">29</sup> However, we must be cautious in recommending this practice––especially considering that, in the ESCRS study, patients still used levofloxacin postoperatively for one week.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">28</sup></span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;"><br style="font-family: Tahoma, Arial, Helvetica, sans-serif;" />Newer-generation fluoroquinolones have become the topical antibiotic of choice in the prevention and treatment of ocular infections due to their high tissue concentrations, low MIC rates and broad spectrum of coverage. Nonetheless, eye care providers must be educated about the rising rates of increased fluoroquinolone resistance in certain pathogens, including MRSA. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">We should make every effort to ensure an accurate diagnosis of bacterial infections to avoid unnecessary overuse of antibiotics. In cases where topical antibiotics are indicated, use them aggressively for a defined period. For infections that do not respond, perform cultures. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <span style="font-family: Arial; font-size: x-small;">Today, we are fortunate to have several extremely effective antibiotic agents in our armamentarium. But, to prevail in the battle against ocular infection, we must use these drugs in a judicious capacity to limit further bactericidal resistance. </span></div> <div style="font-size: 12px; margin-bottom: 12px;"> <em><span style="font-family: Arial; font-size: x-small;">Dr. Muckley is the director of optometric services at Northeast Ohio Eye Surgeons in Kent and Stow, Ohio. She has no financial interest in any of the products mentioned. She can be contacted at <span class="skype_pnh_container" dir="ltr" skype_menu_props="{'numberToCall':'+13306780201' , 'isFreecall':false, 'isMobile':false, 'isRtl':false}" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; color: rgb(0, 175, 253) !important; cursor: pointer !important; direction: ltr !important; display: inline !important; float: none !important; font-family: 'Helvetica Neue Regular', Helvetica, Arial, sans-serif !important; font-size: 1em !important; font-style: normal !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;" tabindex="-1"> <span class="skype_pnh_highlighting_inactive_common" dir="ltr" skypeaction="skype_dropdown" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; direction: ltr !important; display: inline !important; float: none !important; font-size: 1em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;"><span class="skype_pnh_textarea_span" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; direction: ltr !important; display: inline !important; float: none !important; font-size: 1em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;"><img class="skype_pnh_logo_img" src="chrome-extension://lifbcibllhkdhoafpjfnlhfpfgnpldfl/numbers_button_skype_logo.png" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; direction: ltr !important; display: inline !important; float: none !important; font-size: 1em !important; height: 1em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px 5px 0px 0px !important; max-height: 24px !important; max-width: 24px !important; min-height: 8px !important; min-width: 8px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: middle !important; width: 1em !important; word-spacing: normal !important; z-index: 0 !important;" /><span class="skype_pnh_text_span" style="background-attachment: scroll !important; background-color: transparent !important; background-image: none !important; background-position: 0px 0px !important; background-repeat: no-repeat no-repeat !important; border-collapse: separate !important; border: 0px none rgb(0, 0, 0) !important; bottom: auto !important; clear: none !important; clip: auto !important; cursor: pointer !important; direction: ltr !important; display: inline !important; float: none !important; font-size: 1em !important; left: auto !important; letter-spacing: 0px !important; list-style: disc outside none !important; margin: 0px !important; overflow: hidden !important; padding: 0px !important; page-break-after: auto !important; page-break-before: auto !important; page-break-inside: auto !important; position: static !important; right: auto !important; table-layout: auto !important; text-shadow: none !important; top: auto !important; vertical-align: baseline !important; width: auto !important; word-spacing: normal !important; z-index: 0 !important;">330-678-0201</span></span></span></span> or<a href="mailto:DrEDM1@aol.com" style="color: #003366; font-family: Tahoma, Arial, Helvetica, sans-serif;">DrEDM1@aol.com</a>.</span></em></div> <div style="margin-bottom: 12px;"> <span style="font-family: Arial;"><span style="font-family: Tahoma, Arial, Helvetica, sans-serif;">1. Hooper DC. Fluoroquinolone antimicrobial agents. N Engl J Med. 1991 Feb 7;324(6):384-94.<br />2. Mah FS. Fourth-generation fluoroquinolones: New topical agents in the war on ocular bacterial infections. Curr Opin Ophthalmol. 2004 Aug;15(4):316–320.<br />3. Blondeau JM. Comparative in vitro activity of gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin and trovafloxacin against 4151 gram-negative and gram-positive organisms. Int J Antimicrob Agents. 2000 Feb;14(1):45-50.<br />4. Strahilevitz J, Hooper DC. Dual targeting of topoisomerase IV and gyrase to reduce mutant selection: direct testing of the paradigm by using WCK-1734, a new fluoroquinolone, and ciprofloxacin. Antimicrob Agents Chemother. 2005 May;49(5):1949-56.<br />5. Dong Y. Fluoroquinolone action in mycobacteria: effects of C8 substitutions on bacterial growth, survival, and resistance. Antimicrob Agents Chemother. 1998 Nov;42(11):2978-2984.<br />6. Gardner S. Ocular drug penetration and pharmacokinetic principles. Clinical Ophthalmic Pharmacology. Boston, MA: Little Brown & Co;1987:1-52.<br />7. Holland EJ. Human ocular concentrations following topical fluoroquinolone adminstration relative to susceptibility of ocular pathogens. Invest Ophthalmol Vis Sci 2006;47: E-Abstract 1881.<br />8. Donnenfeld ED. Human aqueous humor concentrations of besifloxacin, moxifloxacin, and gatifloxacin after topical ocular application. J Cat Refract Surg. 2011Jun;37(6):1082-89.<br />9. McCaulley JP. Fourth generation fluoroquinolones penetration into aqueous humor in humans. Ophthalmology. 2006 June;113(6):955-59.<br />10. Woodcock J, Toigo T. Iquix. New Drug Application: Clinical Review. March 1, 2004. Available at:<a href="http://www.accessdata.fda.gov/drugsatfda_docs/nda/2004/NDA%2021-571_Iquix_AdminCorres.pdf" style="color: #003366;" target="_parent">www.accessdata.fda.gov/drugsatfda_docs/nda/2004/NDA%2021-571_Iquix_AdminCorres.pdf</a>. Accessed November 17, 2012.<br />11. Lloyd RA. Zymaxid. New Drug Application: Clinical Review. July 30, 2009. Available at:<a href="http://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/UCM214207.pdf" style="color: #003366;" target="_parent">www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/DevelopmentResources/UCM214207.pdf</a>. Accessed November 17, 2012.<br />12. Lindstrom R, Lane S, Cottingham A, et al. Conjunctival concentrations of a new ophthalmic solution formulation of moxifloxacin 0.5% in cataract surgery patients. J Ocul Pharmacol Ther. 2010 Dec;26(6):591-5.<br />13. Murphy MD, Mathis LL. Besivance. Executive Summary: Best Pharmaceuticals for Children Act Drug Use Review in the Pediatric Population. January 5, 2011. Available at:<a href="http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/PediatricAdvisoryCommittee/UCM255069.pdf" style="color: #003366;" target="_parent">www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/PediatricAdvisoryCommittee/UCM255069.pdf</a>. Accessed November 17, 2012.<br />14. Ward KW, Lepage JF, Driot JY. Nonclinical pharmacodynamics, pharmacokinetics, and safety of BOL-303224-A, a novel fluoroquinolone antimicrobial agent for topical ophthalmic use. J Ocul Pharmacol Ther. 2007 Jun;23(3):243-56.<br />15. Noecker RJ, Herrygers LA, Anwaruddin R. Corneal and conjunctival changes caused by commonly used glaucoma medications. Cornea. 2004 Jul;23(5):490-6.<br />16. Okabe K, Kimura H, Okabe J, et al. Effect of benzalkonium chloride on transscleral drug delivery. Invest Ophthalmol Vis Sci. 2005 Feb;46(2):703-8.<br />17. Blondeau JM, Borsos S, Hesje CK. Antimicrobial efficacy of gatifloxacin and moxifloxacin with and without benzalkonium chloride compared with ciprofloxacin and levofloxacin against methicillin-resistant Staphylococcus aureus. J Chemother. 2007 Apr;19(2):146-51.<br />18. Friedlaender MH, Breshears D, Amoozgar B, et al. The dilution of benzalkonium chloride (BAK) in the tear film. Adv Ther. 2006 Nov-Dec;23(6):835-41.<br />19. Oliveira AD, D'Azevedo PA, Francisco W. In vitro activity of fluoroquinolones against ocular bacterial isolates in Sao Paulo, Brazil. Cornea. 2007 Feb;26(2):194-8.<br />20. Kowalski RP, Yates KA, Romanowski E, et al. An ophthalmologist's guide to understanding antibiotic susceptibility and minimum inhibitory concentration data. Ophthalmology. 2005 Nov;112(11):1987.<br />21. Gorwitz RJ. Understanding the success of methicillin-resistant Staphylococcus aureus strains causing epidemic disease in the community. J Infect Dis. 2008 Jan 15;197(2):179-82.<br />22. Haas W, Pillar CM, Torres M, et al. Monitoring antibiotic resistance in ocular microorganisms: Results from the Antibiotic Resistance Monitoring in Ocular micRorganisms (ARMOR) 2009 surveillance study. Am J Ophthalmol. 2011 Oct;152(4):567-574.e3.<br />23. Asbell PA, Sahm DF, Shaw M, et al. Increasing prevalence of methicillin resistance in serious ocular infections caused by Staphylococcus aureus in the United States: 2000 to 2005. J Cataract Refract Surg. 2008 May;34(5):814-8.<br />24. Asbell PA, Colby KA, Deng S. Ocular TRUST: nationwide antimicrobial susceptibility patterns in ocular isolates. Am J Ophthalmol. 2008 Jun;145(6):951-8.<br />25. Colleaux KM, Hamilton WK. Effect of prophylactic antibiotics and incision type on the incidence of endophthalmitis after cataract surgery. Can J Ophthalmol. 2000 Dec;35(7):373-8.<br />26. Moshirfar M, Feiz V, Vitale AT, et al. Endophthalmitis after uncomplicated cataract surgery with the use of fourth-generation fluoroquinolones: a retrospective observational case series. Ophthalmology. 2007 Apr;114(4):686-91.<br />27. Jensen MK, Fiscella RG, Moshirfar M, Mooney B. Third- and fourth-generation fluoroquinolones: retrospective comparison of endophthalmitis after cataract surgery performed over 10 years. J Cataract Refract Surg. 2008 Sep;34(9):1460-7.<br />28. Barry P, Seal DV, Gettinby G, et al. ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study. J Cataract Refract Surg. 2006 Mar;32(3):407-10.<br />29. Shorstein NH, Winthrop KL, Herrinton LJ. Decreased postoperative endophthalmitis rate after institution of intracameral antibiotics in a Northern California eye department. J Cataract Refract Surg. 2012 Oct 1. [Epub ahead of print]<br />30. Milder E. Changes in antibiotic resistance patterns of conjunctival flora due to repeated use of topical antibiotics after intravitral injection. Ophthalmology. 2012 Jul;119(7):1420-4.<br />31. Asbell PA. Ocular TRUST 3: Ongoing Longitudinal Surveillance of Antimicrobial Susceptibility in Ocular Isolates. Poster presented at: Annual Meeting of the American Society of Cataract and Refractive Surgery: April 3-8, 2009; San Francisco.<br />32. Bababeygy SR, Silva RA, Sun Y, Jain A. Rifampin and linezolid in the treatment of methicillin-resistant Staphylococcus aureus preseptal cellulitis. Ophthal Plast Reconstr Surg. 2009 May-Jun;25(3):227-8.<br />33. Hoffmann CJ. Mycobacterium chelonae. Johns Hopkins Antibiotic (ABX) Guide. Available at:<a href="http://www.hopkinsguides.com/hopkins/ub/view/Johns_Hopkins_ABX_Guide/540364/all/Mycobacterium+chelonae" style="color: #003366;" target="_parent">www.hopkinsguides.com/hopkins/ub/view/Johns_Hopkins_ABX_Guide/540364/all/Mycobacterium+chelonae</a>. Accessed November 17, 2012.</span> </span></div> <div style="font-size: 12px;"> <span style="font-family: Arial; font-size: x-small;"><br /></span></div> </div> <br /> </div>

¿Estamos ganando terreno sobre la infección ocular?

Visualización optima 1600x900 pixel Comenta.esta.publicación Para Publicaciones en otros idiomas te invitamos a utilizar el traductor inco...

VER MAS »»»»»»