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).

Alprazolam, a short-acting benzodiazepine, is one of the most widely prescribed drugs in the US. It is approved by the FDA for treatment of anxiety and panic disorder. An extended-release formulation, Xanax XR, which can be taken once a day, recently became available for panic disorder.

The FDA has approved an extended-release (XR) formulation of the benzodiazepine alprazolam (Xanax XR - Pfizer) for treatment of panic disorder, with or without agoraphobia. The new formulation is intended to reduce the need for frequent dosing and problems of interdose anxiety. This review describes the effectiveness of the extended-release formulation, as well as sections on dependence, abuse and withdrawal, adverse effects, and drug interactions. The review concludes with an overall assessment of the drug's efficacy and cost.

Since The Medical Letter last reviewed the choice of benzodiazepines (Volume 23, page 41, 1981), several new drugs have been marketed and some old ones are now available generically. Most of the benzodiazepines available for oral use in the USA are listed in the table on page 28.

Estazolam (ProSom - Abbott), a triazolobenzodiazepine derivative similar in structure to alprazolam (Xanax) and triazolam (Halcion), was recently marketed in the USA for treatment of insomnia.

The FDA recently advised health care professionals and consumers not to use a number of dietary supplements found to contain the phosphodiesterase-5 inhibitor sildenafil (Viagra) or an analog of the drug (www.fda.gov). Although the effects of sildenafil may be noticeable (in men), the presence of other, possibly more toxic adulterants in dietary supplements may be more difficult or impossible to detect.Other drugs previously found in dietary supplements have included lovastatin (Mevacor, and others), estrogen, alprazolam (Xanax, and others), indomethacin (Indocin, and others) and warfarin...

Three benzodiazepines and 16 other compounds are marketed in the USA for treatment of insomnia. Many authorities believe that insomnia is overdiagnosed and overtreated (MK Erman, ed, Sleep Disorders, Psychiatr Clin North Am, Volume 10, Dec 1987).

Fluvoxamine (Luvox - Solvay), a selective serotonin reuptake inhibitor (SSRI), has been approved for treatment of obsessive-compulsive disorder (OCD) by the US Food and Drug Administration. Fluoxetine (Prozac), another SSRI antidepressant, and clomipramine (Anafranil), a tricyclic antidepressant that also inhibits serotonin reuptake, are the only other drugs available for this indication in the USA. Antidepressants that do not inhibit serotonin reuptake have not been effective for treatment of this condition.

Nefazodone (Serzone - Bristol-Myers Squibb) was recently approved by the US Food and Drug Administration for treatment of depression. A phenylpiperazine, nefazodone is chemically related to trazodone (Desyrel, and others).

The FDA now requires boxed warnings in the package inserts of benzodiazepines describing the potential for these drugs to be abused and misused and to cause addiction and physical dependence. Benzodiazepine labels have contained a boxed warning about a risk of serious drug interactions with opioids since 2016.