The investigational oral antiviral drug molnupiravir (Merck/Ridgeback Biotherapeutics) was granted an FDA Emergency Use Authorization (EUA) on December 23, 2021 for treatment of mild to moderate COVID-19 in outpatients ≥18 years old who are at high risk of progressing to severe disease, including hospitalization or death (see Table 1), and for whom alternative treatment options are not available or clinically appropriate. Paxlovid (Pfizer), nirmatrelvir copackaged with ritonavir, was granted an EUA on December 22, 2021. The IV antiviral drug remdesivir (Veklury) was approved by the...

On December 22, 2021, the FDA issued an Emergency Use Authorization (EUA) for the investigational antiviral drug nirmatrelvir copackaged with the HIV-1 protease inhibitor ritonavir (Paxlovid – Pfizer) for oral treatment of mild to moderate COVID-19 in outpatients ≥12 years old who weigh at least 40 kg and are at high risk of progressing to severe disease, including hospitalization or death. Paxlovid was the first oral antiviral drug to be authorized in the US for treatment of COVID-19; Merck's oral antiviral drug molnupiravir was granted an EUA for treatment of COVID-19 on...

Mefloquine hydrochloride (Lariam - Roche), a new antimalarial drug chemically related to quinine, has been approved by the US Food and Drug Administration (FDA) for prevention and treatment of Plasmodium falciparum and P. vivax malaria.

The FDA has approved elagolix (Orilissa – AbbVie), an oral gonadotropin-releasing hormone (GnRH) antagonist, for management of moderate to severe pain associated with endometriosis.

Penpulimab-kcqx (Anniko – Akeso Biopharma), a programmed death receptor-1 (PD-1)-blocking antibody, has been approved by the FDA for use in combination with cisplatin or carboplatin plus gemcitabine for first-line treatment of recurrent or metastatic nonkeratinizing nasopharyngeal carcinoma and for use as monotherapy for metastatic disease in adults with disease progression on or after platinum-based chemotherapy and at least one other prior line of therapy. Penpulimab is the second immune checkpoint inhibitor to be approved in the US for treatment of nasopharyngeal carcinoma;...

Toripalimab-tpzi (Loqtorzi – Coherus Biosciences), a programmed death receptor-1 (PD-1)-blocking antibody, has been approved by the FDA for use in combination with cisplatin and gemcitabine for first-line treatment of recurrent locally advanced or metastatic nasopharyngeal carcinoma and for use as monotherapy for treatment of recurrent unresectable or metastatic nasopharyngeal carcinoma in adults with disease progression on or after platinum-based chemotherapy. It is the first immune checkpoint inhibitor to be approved in the US for treatment of nasopharyngeal carcinoma.

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.

Exenatide injection (Byetta - Amylin/Lilly), a synthetic peptide that stimulates release of insulin from pancreatic beta cells, has been approved by the FDA as adjunctive therapy for patients with type 2 diabetes who have not achieved optimal glycemic control on metformin (Glucophage, and others), a sulfonylurea, such as glyburide (DiaBeta, and others), or both. Exenatide is not indicated for use with insulin.

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.

With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by parasites. The table in this document lists first-choice and alternative drugs for most parasitic infections.