In a study of the interaction between alcohol and the calcium-channel blocker felodipine (Plendil), the grapefruit juice vehicle for the alcohol appeared to increase felodipine plasma concentrations. Subsequent studies have found that grapefruit juice increases plasma concentrations of several calcium-channel blockers and of some other drugs as well (DG Bailey et al, Clin Pharmacokinet, 26:91, 1994).

Rapid exposure to altitudes more than 8,000 feet above sea level can cause serious medical problems. Since the last Medical Letter article on this subject (Vol. 30, page 89, 1988), some new information on prevention and treatment of these disorders has been reported.

The FDA has approved flibanserin (Addyi – Sprout) for treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD) not caused by another medical or psychiatric condition, the effects of another drug, or relationship difficulties. Flibanserin is the first drug to be approved for treatment of HSDD. It is not approved for use in men or postmenopausal women. Previous FDA reviews of flibanserin in 2010 and 2013 did not result in approval.

The FDA has approved remimazolam (Byfavo – Acacia Pharma), an ultra-short-acting IV benzodiazepine, for induction and maintenance of sedation in adults undergoing procedures of up to 30 minutes' duration.

The FDA has approved use of gamma hydroxybutyrate (sodium oxybate is the official generic name; Xyrem - Orphan Medical) for oral treatment of cataplexy in patients with narcolepsy. Gamma hydroxybutyrate (GHB), a metabolite of gamma-aminobutyric acid (GABA), is a central-nervous-system depressant marketed in Europe for use in general anesthesia. In recent years it has been notorious for its use in "date-rape" (Medical Letter 2002; 44:21). Xyrem is a Schedule III controlled substance.

Oliceridine (Olinvyk - Trevena), an IV opioid agonist, has been approved by the FDA for management of acute pain severe enough to require an opioid and for which alternative treatment options are inadequate.

The FDA has approved the oral second-generation antipsychotic drug brexpiprazole (Rexulti – Otsuka/Lundbeck) for once-daily treatment of agitation associated with dementia due to Alzheimer's disease (AD). Brexpiprazole is the first drug to be approved in the US for this indication. It is also approved for treatment of schizophrenia and as an adjunct to antidepressants for treatment of major depressive disorder.

The FDA has approved a sublingual film formulation of the alpha-2 adrenergic receptor agonist dexmedetomidine (Igalmi — BioXcel Therapeutics) for acute treatment of agitation associated with schizophrenia or bipolar I or II disorder in adults. It is the first alpha-2 agonist and the only sublingual film to be approved for this indication. Dexmedetomidine has been available for many years in an injectable formulation (Precedex) for sedation in the intensive care unit and to facilitate procedures such as mechanical ventilation.

Telithromycin (Ketek - Aventis) has been approved by the FDA for oral treatment of mild to moderate community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute bacterial sinusitis in patients age 18 and older. The drug is the first in a new class of antibiotics, the ketolides, derived from the macrolide erythromycin. Telithromycin has been marketed in Europe since 2001.

View the Comparison Table: Some Oral/Transdermal Opioid Analgesics