The CDC is recommending that persons at high risk of mpox (see Table 1) receive two doses of the Jynneos vaccine. The recommendation follows reports of a recent cluster of mpox cases in the US and warnings about the risk of a renewed outbreak during the spring and summer as people gather for festivals and other events. The CDC does not recommend routine immunization against mpox for the general population.

Itraconazole (Sporanox - Janssen), an antifungal triazole, has been approved by the US Food and Drug Administration (FDA) for oral treatment of histoplasmosis and blastomycosis. These two endemic mycoses occur both in normal hosts and in immunocompromised patients, such as those with AIDS (RW Bradsher, Clin Infect Dis, 14:S82, 1992; LJ Wheat, Clin Infect Dis, 14:S91, 1992).

Since the last Medical Letter review of cephalosporin antibiotics (volume 25, page 57, 1983), many new cephalosporins have become available in the USA.

The FDA has recently approved 2 new drugs for treatment of chronic hepatitis C virus (HCV) infection. Simeprevir (Olysio – Janssen) is the third oral protease inhibitor to be approved for use in combination with peginterferon and ribavirin for treatment of chronic HCV genotype 1 infection in adults with compensated liver disease. Telaprevir (Incivek) and boceprevir (Victrelis) were approved in 2011 for the same indication. Sofosbuvir (Sovaldi – Gilead), a nucleotide analog polymerase inhibitor that has been approved for use with and without interferon for treatment of multiple HCV...

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 vonoprazan, a potassium-competitive acid blocker, copackaged with amoxicillin (Voquezna Dual Pak – Phathom) and with amoxicillin and clarithromycin (Voquezna Triple Pak) for treatment of Helicobacter pylori infection in adults. Vonoprazan is the first potassium-competitive acid blocker to be approved in the US. It has been available in Japan for treatment of various acid-related disorders since 2014. Vonoprazan is not available alone in the US.

The FDA has approved Genvoya (Gilead), a fixed-dose combination of the integrase strand transfer inhibitor (INSTI) elvitegravir, the pharmacokinetic enhancer cobicistat, and the nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) emtricitabine and tenofovir alafenamide, for treatment of HIV-1 infection in patients ≥12 years old. This is the first approval for tenofovir alafenamide (TAF), a tenofovir prodrug. Stribild, a fixed-dose combination of elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (TDF), was approved in 2012.

The FDA has approved Vowst (Seres Therapeutics/Nestle HealthScience), an oral capsule containing live fecal microbiota spores, for prevention of additional recurrences of Clostridioides difficile infection (CDI) in adults. Vowst is the first orally administered microbiota-based treatment to be approved for this indication. A rectally-administered live fecal microbiota-based suspension (Rebyota) was approved in 2022 for the same indication. Neither product is approved for acute treatment of CDI.

The FDA has approved three new once-daily fixed-dose antiretroviral drug combinations for treatment of HIV-1 infection. Symfi and Symfi Lo (Mylan) contain the non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz and the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine and tenofovir disoproxil fumarate (TDF) and were approved as complete antiretroviral regimens. Symfi Lo contains a lower dose of efavirenz than both Symfi and Atripla, a fixed-dose combination of efavirenz, TDF, and the NRTI emtricitabine that was approved in 2006. Cimduo (Mylan), which...

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.