View the Expanded Table: Statins

The ability of grapefruit juice to increase serum concentrations of drugs was first discovered during a study of the effect of ethanol on felodipine (Plendil) pharmacokinetics. Double-strength grapefruit juice used to disguise the taste of ethanol resulted in higher than expected serum concentrations of felodipine (DG Bailey et al, Clin Invest Med 1989; 12:357).

The FDA has approved Epclusa (Gilead), a fixed-dose combination of sofosbuvir (Sovaldi) and velpatasvir, a new direct-acting antiviral agent, for oral treatment of chronic hepatitis C virus (HCV) infection. Epclusa is the first oral combination to be approved for treatment of all six major HCV genotypes.

The lipid-lowering drug rosuvastatin is now available in a sprinkle capsule formulation (Ezallor Sprinkle – Sun Pharma). Rosuvastatin tablets (Crestor, and generics) have been available since 2003.1,2The new formulation is being marketed specifically for residents of long-term care facilities who have difficulty swallowing. Ezallor Sprinkle capsules can be swallowed whole or opened and their contents sprinkled over applesauce or mixed with water for administration via nasogastric tube.For those long-term care residents who still have a reasonable indication for a statin but have difficulty...

The FDA has amended its Emergency Use Authorization (EUA) for Paxlovid (Pfizer), the investigational oral antiviral drug nirmatrelvir copackaged with oral ritonavir, to allow for it to be prescribed by licensed pharmacists in certain situations. Paxlovid is authorized for oral treatment of mild to moderate COVID-19 in high-risk outpatients ≥12 years old who weigh at least 40 kg. NIH guidelines list it as the treatment of choice for COVID-19 in high-risk adult outpatients.

Vardenafil (Levitra -Bayer) is the second oral drug approved by the FDA for treatment of erectile dysfunction. Sildenafil (Viagra - Medical Letter 1998; 40:51), the first oral drug, has been available for 5 years. Pharmacokinetics, effectiveness, adverse effects, dosage and cost of the new drug are reviewed. Whether it offers any benefits over sildenafil is discussed.

About 2.5 million persons in the US had hepatitis C between 2017 and 2020. Guidelines from the American Association for the Study of Liver Diseases (AASLD) and the Infectious Diseases Society of America (IDSA) on management of hepatitis C virus (HCV) infection were updated in 2023.

View Table: Mechanisms of Drug Interactions

View the Treatment of COVID-19 in High-Risk Outpatients Chart

The physiologic changes that occur with aging can affect the pharmacokinetics and pharmacodynamics of many prescription and over-the-counter drugs, increasing the likelihood of adverse effects.