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...

Patients may ask about taking elderberry for prevention and treatment of influenza. Products containing elderberry are promoted for relief of cold and flu symptoms and as an immune system booster.

The FDA has approved the antiviral drug remdesivir (Veklury – Gilead) for IV treatment of COVID-19 in hospitalized patients who are ≥12 years old and weigh ≥40 kg. Hospitalized children who are <12 years old or weigh <40 kg can receive remdesivir through an Emergency Use Authorization (EUA). Remdesivir is the first drug to be approved in the US for treatment of COVID-19.

Remdesivir (Veklury – Gilead), an investigational antiviral drug administered by IV infusion, is now available through an FDA Emergency Use Authorization (EUA) for treatment of COVID-19 in all hospitalized patients. An earlier EUA limited use of the drug to patients hospitalized with severe disease.

Our article on Antiviral Drugs for Prophylaxis and Treatment of Influenza (Med Lett Drugs Ther 2005;47:93) mentioned possible use of amantadine (Symmetrel, and others) and rimantadine (Flumadine, and others), but warned that the incidence of resistance has increased substantially. The CDC recently issued a Health Alert (www.cdc.gov) saying that current evidence indicates that a high proportion of circulating influenza A viruses in the US are now resistant to amantadine and rimantadine and they should not be used for this indication, at least this year. Click here to go to this update...

Since publication of our recent article on antiviral drugs for influenza, increased levels of resistance to oseltamivir (Tamiflu) have been detected in influenza A H1N1 strains.

The FDA has approved baloxavir marboxil (Xofluza – Shionogi/Genentech), the first polymerase acidic (PA) endonuclease inhibitor, for single-dose, oral treatment of acute uncomplicated influenza in patients ≥12 years old. Baloxavir is the first drug with a new mechanism of action to be approved for treatment of influenza in almost 20 years.

The FDA has approved peramivir (Rapivab – BioCryst), an IV neuraminidase inhibitor administered as a single dose, for treatment of acute uncomplicated influenza in patients ≥18 years old who have had symptoms for no more than 2 days. Peramivir was available temporarily in the US during the 2009-2010 influenza season under an emergency use authorization for treatment of hospitalized patients. It has been available in some Asian countries since 2010. Peramivir is the third neuraminidase inhibitor to be approved in the US. Oseltamivir (Tamiflu), which is taken orally, and zanamivir...

The FDA recently announced changes in the labeling of the hepatitis C drugs Sovaldi (sofosbuvir) and Harvoni (sofosbuvir/ledipasvir) to warn about a risk of serious and potentially fatal bradycardia when either drug is taken with the antiarrhythmic drug amiodarone (Cordarone, and others).1 Symptomatic bradycardia was reported following initiation of treatment with Harvoni or with Sovaldi plus simeprevir (Olysio) or the investigational antiviral drug daclatasvir in 9 patients already taking amiodarone; it occurred within 24 hours of starting hepatitis C therapy in 6 patients and within 2-12...

Ganciclovir sodium (Cytovene - Syntex), a synthetic antiviral nucleoside analog, is now available in the USA for intravenous treatment of cytomegalovirus (CMV) retinitis in immunocompromised patients. CMV retinitis occurs in 20% to 25% of patients with AIDS.