S-adenosyl-methionine (SAM; SAMe; ademetionine; adomet), an endogenous compound synthesized from methionine and adenosine-triphosphate (ATP), has been marketed in stores and on the internet as a dietary supplement to promote "emotional well being."

Zolpidem (Ambien - Searle), an imidazopyridine hypnotic available in Europe for several years, was recently approved by the US Food and Drug Administration for short-term treatment of insomnia.

Citalopram hydrobromide (Celexa - Forest/Parke-Davis), a selective serotonin reuptake inhibitor (SSRI) available in Europe since 1989, has now been approved by the US Food and Drug Administration (FDA) for treatment of depression. It is being advertised as having a 'favorable side-effect profile.'

Alprazolam (Xanax - Upjohn), a triazolobenzodiazepine previously available in the USA for treatment of anxiety (Medical Letter 24:41, 1982), was recently approved by the US Food and Drug Administration (FDA) for treatment of panic disorder, with or without agoraphobia. According to one report, alprazolam was the fifth most widely prescribed drug in the USA last year (American Medical News, March 4, 1991, page 4).

Fluoxetine (Prozac - Dista), a phenylpropylamide, is the first serotonin-reuptake blocker introduced in the USA for treatment of . It is being promoted as causing fewer adverse effects than other antidepressants. Claims of greater safety and patient tolerability have often been made for new non-tricyclic antidepressants in recent years, but unpredicted adverse effects have emerged with widespread use, including priapism with trazodone (Desyrel - Medical Letter, 26:35, 1984) and fatal hemolytic anemia with nomifensine (Merital - Medical Letter, 27:73, 1985).

Mibefradil dihydrochloride (Posicor - Roche), a chemically distinct nondihydropyridine calcium-channel blocker, has been approved by the US Food and Drug Administration (FDA) and is being heavily promoted as the first T-type calcium-channel blocker for treatment of hypertension and chronic stable angina.

Recombinant interleukin-2 (IL-2; Proleukin - Cetus), a lymphokine that stimulates growth of T lymphocytes, is available from the National Cancer Institute on an investigational basis for treatment of renal cell carcinoma and malignant melanoma. Although recently released in many European countries, the drug has not been approved for marketing by the US Food and Drug Administration.

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.

As the weather becomes warmer, physicians may see more photosensitivity reactions due to systemic or topical drugs, perfumes, cosmetics or sunscreens. Even brief exposure to sunlight in warm or cold weather can cause intense cutaneous reactions in patients with drug-induced photosensitivity, and some patients may continue to be sensitive to sunlight long after stopping use of the offending agent.

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