This article includes recommendations for management of most sexually transmitted infections (STIs) other than HIV and viral hepatitis. Some of the indications and dosages recommended here have not been approved by the FDA (see Table 1).

Acute toxic reactions to drugs of abuse continue to be important problems. Some patients may have mixed intoxications with complex combinations of signs and symptoms.

The gram-positive anaerobic bacillus Clostridium difficile is the most common identifiable cause of antibiotic-associated diarrhea. The antibiotics most often implicated have been ampicillin, second and third generation cephalosporins, clindamycin and fluoroquinolones. The emergence in recent years of a new, more toxic epidemic strain (BI/NAP1), possibly related to widespread use of fluoroquinolones, has caused a marked increase in the incidence and severity of C. difficile-associated disease (CDAD).

The FDA has approved daridorexant (Quviviq – Idorsia), an orexin receptor antagonist, for treatment of sleep-onset and/or sleep-maintenance insomnia in adults. Daridorexant is the third orexin receptor antagonist to be approved for this indication; suvorexant (Belsomra) and lemborexant (Dayvigo) were approved earlier.

Fluticasone furoate nasal spray (Veramyst - GSK) is now available for once-daily treatment of seasonal and perennial allergic rhinitis in adults and children ≥2 years old. It is similar to fluticasone propionate nasal spray (Flonase, and others), which is now available generically.

The FDA has approved lixisenatide (Sanofi), a short-acting injectable GLP-1 (glucagon-like peptide-1) receptor agonist, for once-daily treatment of adults with type 2 diabetes, both alone (Adlyxin) and in a fixed-ratio combination with insulin glargine (Soliqua 100/33). Lixisenatide has been available since 2013 in many other countries as Lyxumia. It is the fifth GLP-1 receptor agonist to be approved in the US.

The severity and rapid spread of COVID-19 (caused by SARS-CoV-2) have raised questions about the use of some drugs in patients with the disease and whether currently available drugs could be effective in treating it. Definitive answers are lacking, but some recommendations can be made. For additional information on specific drugs, see our table Some Drugs Being Considered for Treatment of COVID-19.

Cholesterol management guidelines from the American College of Cardiology/American Heart Association Task Force were last published in 2019.

Varenicline tartrate (Chantix - Pfizer) is now available for oral treatment of tobacco dependence. Some other drugs for this indication are listed in this article.

Patients with seasonal allergies often experience nasal itching and congestion, sneezing, rhinorrhea, and itchy, watery eyes. Oral, intranasal, and ophthalmic preparations are widely available over the counter (OTC) for relief of symptoms. Prescription products for management of allergic rhinitis and allergic conjunctivitis are reviewed separately.