This issue includes reviews of drugs for glaucoma, age-related macular degeneration (AMD), bacterial conjunctivitis, and dry eye disease. Allergic conjunctivitis is reviewed in a separate issue.

Antimicrobial prophylaxis can decrease the incidence of postoperative surgical site infection after some procedures. Since the last Medical Letter article on this subject, consensus guidelines have been published. Recommendations for prophylaxis in specific surgical procedures are listed in Table 1.

Drugs for glaucoma, age-related macular degeneration, bacterial conjunctivitis, and dry eyes are reviewed here. Drugs for the treatment of allergic conjunctivitis will be reviewed in a future issue of Treatment Guidelines on Drugs for Allergic Disorders.

Antimicrobial prophylaxis can decrease the incidence of postoperative infection, particularly surgical site infection, after some procedures. Recommendations for such prophylaxis are listed in the table that begins on page 74. Antimicrobial prophylaxis for dental procedures to prevent endocarditis was recently discussed in The Medical Letter.

Drugs for glaucoma, age-related macular degeneration, bacterial conjunctivitis, and dry eyes are reviewed here. Ophthalmic drugs can have local and systemic adverse effects. In addition, for some elderly patients, the complexity of self-administering numerous ophthalmic drugs may be the limiting factor in their ability to care for themselves. Drugs for the treatment of allergic conjunctivitis will be reviewed in a future issue of Treatment Guidelines on Drugs for Allergic Disorders.

The FDA has approved the fluoroquinolone besifloxacin 0.6% ophthalmic suspension (Besivance - Bausch & Lomb) for treatment of bacterial conjunctivitis caused by susceptible bacteria. According to the manufacturer, this product was developed specifically for ophthalmic use in a specialized vehicle designed to prolong contact time on the ocular surface. Besifloxacin is not available for systemic use.

Antimicrobial prophylaxis can decrease the incidence of infection, particularly surgical site infection, after certain procedures. Recommendations for prevention of surgical site infection are listed in the table that begins on page 48. Antimicrobial prophylaxis for dental procedures to prevent endocarditis is discussed in The Medical Letter 2007; 49:99.

Antimicrobial prophylaxis can decrease the incidence of infection, particularly surgical site infection, after certain procedures. Recommendations for prevention of surgical site infection are listed in this article.

A study now available on the web site of The New England Journal of Medicine (LY Park-Wyllie et al. Outpatient gatifloxacin therapy and dysglycemia in older adults. www.nejm.org, published online March 1, 2006) reports an increased risk of hypoglycemia (RR 4.3) and hyperglycemia (RR 16.7) with use of gatifloxacin (Tequin), a fluoroquinolone antibiotic. The Medical Letter published an article on this risk in 2003 (vol. 45, page 64); at that time the extent to which other fluoroquinolones carried the same risk was unclear. The recent report indicates that, except for a slightly increased relative risk of hypoglycemia (RR 1.5) with levofloxacin (Levaquin), they do not. Gatifloxacin, levofloxacin, moxifloxacin (Avelox) and gemifloxacin (Factive) are more active than other quinolones against gram-positive organisms such as Streptococcus pneumoniae, including strains highly resistant to penicillin; they are sometimes called "the respiratory quinolones." Given the availability of other drugs with similar in vitro and clinical activity, there is no good reason to continue to use gatifloxacin.

Methicillin-resistant Staphylococcus aureus (MRSA) infections, which have been a concern for many years, previously occurred primarily in hospitalized patients and those recently treated with antibiotics. In the past few years, there has been an increasing incidence worldwide of community-associated (CA) MRSA infections in patients without recent antibiotic exposure or contact with the healthcare system.

Tuberculosis (TB) is still a problem in the United States, even though the incidence continues to decline in most of the country (MMWR Morbid Mortal Wkly Rep 2004; 53:209). Treatment of TB can be divided into treatment of latent infection diagnosed by a positive PPD and treatment of active clinical TB. Guidelines with detailed management recommendations are available from the US Centers for Disease Control and Prevention (CDC) (MMWR Morbid Mortal Wkly Rep 2003; 52RR-11:1).

Gemifloxacin (Factive - Oscient), a new oral fluoroquinolone antibiotic, has been approved by the FDA for 5 days' treatment of acute bacterial exacerbations of chronic bronchitis (ABECB) and 7 days' treatment of mild to moderate community-acquired pneumonia (CAP) in adults. For the next 6-8 months it will only be available, presumably for commercial reasons, in states east of the Rocky Mountains.

Telithromycin (Ketek - Aventis) has been approved by the FDA for oral treatment of mild to moderate community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute bacterial sinusitis in patients age 18 and older. The drug is the first in a new class of antibiotics, the ketolides, derived from the macrolide erythromycin. Telithromycin has been marketed in Europe since 2001.

Antimicrobial prophylaxis can decrease the incidence of infection, particularly surgical site infection, after certain operations, but this benefit must be weighed against the risks of toxic and allergic reactions, emergence of resistant bacteria, adverse drug interactions, superinfection and cost. Medical Letter consultants generally recommend antimicrobial prophylaxis only for procedures with high infection rates, those involving implantation of prosthetic material, and those in which the consequences of infection are likely to be especially serious.

Two new fluoroquinolone solutions, moxifloxacin 0.5% (Vigamox - Alcon) and gatifloxacin 0.3% (Zymar - Allergan) are now available in the US for ophthalmic use in treatment of bacterial conjunctivitis.

New drugs for bacterial infections and new information about older drugs continue to become available. Empirical treatment of some common bacterial infections is discussed in this article. A table listing the drugs of choice and alternatives for each pathogen begins on page 18. These recommendations are based on results of susceptibility studies, clinical trials and the opinions of Medical Letter consultants. Local resistance patterns should be taken into account. Trade names are listed on page 24.

The choice of drugs for treatment of pneumonia depends on the most likely pathogens causing the infection and local antimicrobial resistance patterns. Factors such as severity of illness, presence of co-morbid conditions and whether the infection is community or hospital-acquired also need to be considered.

The July 2003 edition of the Canadian Adverse Reaction Newsletter, published by Health Canada (the Canadian FDA), reported that the Health Canada database had received more spontaneous reports of hypoglycemia (19) and hyperglycemia (7) with gatifloxacin (Tequin) than with other quinolone antibiotics.

Augmentin XR (GlaxoSmithKline), an oral extended-release combination of amoxicillin and the beta-lactamase inhibitor clavulanic acid, is now being promoted for treatment of acute bacterial sinusitis and community-acquired pneumonia. Augmentin XR contains a higher dose of amoxicillin than Augmentin.

Gatifloxacin and moxifloxacin are now available for once-daily treatment of patients with community-acquired pneumonia, acute bacterial exacerbations of chronic bronchitis, or acute sinusitis.