The FDA has approved esketamine (Spravato – Janssen), an N-methyl-D-aspartate (NMDA) receptor antagonist, for intranasal treatment (in conjunction with an oral antidepressant) of adults with treatment-resistant depression (TRD). This is the first FDA approval for esketamine, which is the S-enantiomer of the intravenous anesthetic ketamine (Ketalar, and generics). In recent years, IV ketamine has been increasingly used (off-label) for treatment of TRD.

View the Comparison Chart: Some Drugs for Irritable Bowel Syndrome with Constipation (IBS-C)

The FDA has approved the 5-HT4 receptor agonist prucalopride (Motegrity – Shire) for treatment of chronic idiopathic constipation (CIC) in adults. Prucalopride is the only drug currently approved in the US for treatment of CIC that stimulates colonic peristalsis. It has been available in Europe and Canada for several years.

The FDA has approved a once-daily, extended-release oral suspension of methylphenidate (Quillivant XR – Pfizer) for treatment of attention-deficit/hyperactivity disorder (ADHD). It is the first liquid formulation of the drug to be marketed for once-daily use. A short-acting oral solution (Methylin, and generics) has been available since 2003.

The injectable glucose-dependent insulinotropic polypeptide (GIP)/glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide (Zepbound) has been approved by the FDA for treatment of moderate to severe obstructive sleep apnea (OSA) in adults with obesity. It is the first drug to be approved in the US for this indication. Zepbound is also approved for chronic weight management in adults with obesity and in those who are overweight and have at least one weightrelated comorbidity. Tirzepatide is also available as Mounjaro for treatment of type 2 diabetes.

Dehydroepiandrosterone (DHEA) is an adrenal androgen now being marketed as a "food supplement"in health food stores. DHEA is not approved for any indication by the US Food and Drug Administration (FDA).

The Medical Letter has received many inquiries about use of glucosamine, a basic constituent of articular cartilage glycosaminoglycans, for treatment of arthritis. A recently published book (The Arthritis Cure), several television news shows, and articles in The New York Times have suggested it may be effective for treatment of osteoarthritis. Glucosamine is sold as a 'dietary supplement' in the USA.

Belotero Balance (Merz), an injectable hyaluronic acid dermal filler, has been approved by the FDA for temporary correction of moderate-to-severe facial wrinkles and folds. Several other hyaluronic acid products are also available for this indication (e.g., Restylane, Perlane, Juvéderm). They have supplanted bovine collagen products, which persist for a shorter time and cause more allergic reactions.

Rotigotine (Neupro - Schwarz Pharma), a nonergot dopamine agonist in a transdermal patch formulation, was recently approved by the FDA for treatment of early Parkinson's disease (PD).

Darbepoetin alfa (Aranesp) has been approved by the FDA for treatment of anemia caused by chronic renal disease and will probably also be approved for use in patients with cancer..