Anascorp (Rare Disease Therapeutics), an intravenously administered antivenom derived from horse serum, has been approved by the FDA for treatment of clinical signs of scorpion envenomation.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

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 ziconotide (Prialt - Elan) intrathecal infusion for management of severe chronic pain in patients who are intolerant of or refractory to other treatments. Ziconotide is a synthetic neuronal N-type calcium channel blocker. It is intended for use with a programmable implanted microinfusion device, but an external microinfusion device can be used temporarily.

Solifenacin succinate (VESIcare - Yamanouchi and GlaxoSmithKline) and darifenacin hydrobromide (Enablex - Novartis) have been approved by the FDA for oral treatment of overactive bladder.

The FDA has approved Viekira Pak (Abbvie), a fixed-dose combination of two new direct-acting antiviral agents (ombitasvir, paritaprevir) with the pharmacologic enhancer ritonavir in one tablet, co-packaged with a third new direct-acting antiviral agent (dasabuvir) in a second tablet, for oral treatment of chronic hepatitis C virus (HCV) genotype 1 infection. Genotype 1 is responsible for 70-80% of HCV infections in the US.

Fentanyl, a synthetic opioid previously available for parenteral use in anesthesia (Sublimaze, and others) and in a transdermal patch for chronic pain (Duragesic - Medical Letter, 34:97, 1992), has now also been marketed as a raspberry-colored lozenge on a plastic handle (Fentanyl Oralet - Abbott), which resembles a lollipop. The new formulation will probably be promoted mainly for premedication of children before anesthesia, but has also been approved by the US Food and Drug Administration (FDA) for preanesthetic use in adults and for use in anesthesia or 'monitored anesthesia care' in...

The oral kinase inhibitors dabrafenib (Tafinlar – GSK) and trametinib (Mekinist – Novartis) have been approved by the FDA for use together for a sixth indication: treatment of low-grade glioma (LGG) with a BRAF V600E mutation in patients ≥1 years old who require systemic therapy. This combination is the first systemic therapy to be approved in the US for first-line treatment of LGG with a BRAF V600E mutation in pediatric patients. The FDA also approved new oral formulations of both drugs for patients who are unable to swallow dabrafenib capsules or trametinib...

Telavancin (Vibativ - Astellas and Theravance), a lipoglycopeptide derivative of vancomycin (Vancocin, and others), has received FDA approval for treatment of complicated skin and skin structure infections caused by susceptible gram-positive bacteria in adults.

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...