The FDA has approved two new drugs for treatment of previously-treated unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer: fam-trastuzumab deruxtecannxki (Enhertu – Daiichi-Sankyo/AstraZeneca), an IV HER2-directed monoclonal antibody linked to the topoisomerase I inhibitor DXd, and tucatinib (Tukysa – Seagen), an oral tyrosine kinase inhibitor.

The FDA has approved opicapone (Ongentys – Neurocrine), a peripherally-acting reversible catechol-O-methyltransferase (COMT) inhibitor, for oral use as an adjunct to carbidopa/levodopa in adults with Parkinson’s disease (PD) who experience "off" episodes. It is the third COMT inhibitor to be approved for this indication; tolcapone (Tasmar, and generics) and entacapone (Comtan, and generics) were approved earlier. Opicapone has been available in Europe since 2016.

A new CDC guideline for prescribing opioids for pain recently became available. Nonopioid drugs for pain were reviewed in a previous issue.

Every pharmaceutical drug is a dose-dependent poison. This article describes the clinical presentation and treatment of some dangerous overdoses commonly reported in adults.

In the short time since fluoxetine (Prozac - Lilly) first became available in the USA (Medical Letter, 30:45, 1988), it has become the most frequently prescribed of all antidepressants. Some recent reports, however, have questioned its safety.

Terbinafine (Lamisil - Sandoz), an allylamine synthetic antifungal, previously available in the USA in a topical formulation (Medical Letter, 35:76, 1993) has now been marketed for oral use in the treatment of fungal nail infections caused by dermatophytes. Oral terbinafine has been available in Europe since 1992.

Troglitazone (Rezulin - Parke-Davis), the first of a new class of thiazolidinedione derivatives ('glitazones') for diabetes, has been marketed for oral treatment of noninsulin- dependent diabetes mellitus (NIDDM) in patients who take more than 30 units of insulin daily and still have a glycosylated hemoglobin concentration (HbA1c) of 8.5% or higher.

Bosentan (Tracleer - Actelion), a non-peptide endothelin receptor antagonist, has been approved by the FDA for oral treatment of patients who have pulmonary arterial hypertension (PAH) with symptoms of dyspnea at rest or with minimal exertion.

Aprepitant (Emend - Merck), the first substance P/neurokinin 1 (NK₁) receptor antagonist to be approved by the FDA, is now available for oral use with corticosteroids and selective serotonin (5-HT₃) receptor antagonists to prevent nausea and vomiting caused by highly emetogenic anticancer drugs such as cisplatin.

The FDA has approved a new genetic test to identify patients who may be at increased risk of severe toxicity when treated with the cancer chemotherapy drug irinotecan (Camptosar). The Invader UGT1A1 Molecular Assay (Third Wave Technologies) detects the UGT1A1*28 allele, a variation in the uridine diphosphate glucuronosyltranferase 1A1 (UGT1A1) gene. The FDA recently revised the safety labeling for irinotecan, recommending that the dosing of irinotecan be reduced for patients who are homozygous for the UGT1A1*28 allele.