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.

Influenza is generally a self-limited illness, but pneumonia, respiratory failure, and death can occur, especially in persons at increased risk for influenza complications (see Table 1). Updated information on influenza activity and antiviral resistance is available from the CDC at cdc.gov/flu.

Annual vaccination against influenza A and B viruses is recommended in the US for everyone ≥6 months old without a contraindication. Influenza vaccines available in the US for the 2025-2026 season are listed in Table 2.

The drugs of choice for treatment of viral infections (other than HIV) and their dosages are listed in Tables 1-6 on the pages that follow. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used for the prevention of viral infections are discussed elsewhere.

Excessive exposure to ultraviolet (UV) radiation can cause erythema, photoaging, and skin cancer. Sunscreens are widely used to reduce these risks, but questions remain about their effectiveness and safety. In 2021, the FDA proposed a rule that would require additional safety studies for some sunscreen active ingredients and mandate better UVA protection in sunscreen products.

Tuberculosis (TB) is still a common cause of death worldwide, and the prevalence of drug-resistant TB poses challenges to its treatment and control. Guidelines with detailed management recommendations are available from the American Thoracic Society, Centers for Disease Control and Prevention (CDC) and Infectious Diseases Society of America (IDSA).

The drugs of choice for treatment of fungal infections are listed in the table that begins on page 62. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines for some of these infections are available online from the Infectious Diseases Society of America (www.idsociety.org).

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.

An oral nonopioid analgesic is often sufficient for acute treatment of mild to moderate migraine pain without severe nausea or vomiting. A triptan is the drug of choice for treatment of moderate to severe migraine in most patients without vascular disease. Treatment of pain when it is still mild to moderate in intensity improves headache response and reduces the risk of recurrence.

The text that follows reviews some common bacterial infections and their empiric treatment pending the results of culture and susceptibility testing. The recommendations made here are based on the results of susceptibility studies, clinical trials, and the opinions of Medical Letter reviewers. Tables 1 and 2 list the usual dosages of antibacterial drugs.