Thalidomide is now available as an investigational drug in the USA. A synthetic derivative of glutamic acid, it was marketed in Europe in 1957 as a sedative but withdrawn four years later after being associated with severe human teratogenicity (PF DArcy and JP Griffin, Adverse Drug React Toxicol Rev, 13:65, 1994). The drug has since been found effective for several different indications.

Adapalene (Differin - Galderma), a synthetic retinoid analog, has been marketed in the USA in a 0.1% gel formulation for topical treatment of acne vulgaris.

The FDA has approved another fixed combination of the antibiotic clindamycin phosphate and the oxidizing agent benzoyl peroxide (Onexton Gel 1.2%/3.75% – Valeant) for topical treatment of acne in patients ≥12 years old. Topical products containing the same drugs have been available for many years. Onexton Gel contains a new strength of benzoyl peroxide.

The FDA has approved setmelanotide (Imcivree – Rhythm), a subcutaneously injected melanocortin 4 (MC4) receptor agonist, for chronic weight management in patients ≥6 years old with obesity due to pro-opiomelanocortin (POMC) deficiency, proprotein subtilisin/kexin type 1 (PCSK1) deficiency, or leptin receptor (LEPR) deficiency.

Topical ivermectin lotion 0.5% (Sklice, and generics), which has been available by prescription since 2012, is now FDA-approved for sale over the counter (OTC) for treatment of head lice in patients ≥6 months old. Ivermectin is also available by prescription as a 1% cream (Soolantra) approved for topical treatment of inflammatory lesions of rosacea and in oral tablets (Stromectol, and generics) for treatment of various parasitic infections.

The FDA has approved Zunveyl (Alpha Cognition), a delayed-release formulation of the prodrug benzgalantamine, for treatment of mild to moderate dementia of Alzheimer's disease (AD). Immediate- and extended-release formulations of the acetylcholinesterase inhibitor galantamine have been available in the US for years for treatment of AD.

A variety of glucose monitoring devices have been used in an effort to reduce the hypoglycemia and wide glucose excursions that complicate insulin treatment of diabetes. Since the last Medical Letter issue reviewing such devices, more continuous glucose monitoring (CGM) systems have become available. Five devices available now, and two expected to be marketed soon, are listed in the table on page 14. The FDA has approved continuous glucose devices only for the observation of glucose trends.

A topical formulation of 0.75% metronidazole gel (MetroGel - Curatek), an antibacterial, antiparasitic agent, was recently approved by the US Food and Drug Administration for treatment of rosacea.

Dirithromycin (Dynabac - manufactured by Lilly, distributed by Bock), an oral macrolide antibiotic chemically similar to erythromycin, clarithromycin (Biaxin) and azithromycin (Zithromax), has been approved for marketing by the US Food and Drug Administration (FDA).

Thalidomide (Thalomid - Celgene), a synthetic derivative of glutamic acid, has been approved by the FDA for use in treatment of leprosy. Thalidomide was marketed in Europe in 1957 as a sedative but withdrawn four years later after being associated with severe human teratogenicity. The drug has since been found to be effective for several different indications.