The FDA has approved the marketing of an extended-release formulation of trazodone (Oleptro – Angelini Labopharm) for treatment of major depressive disorder in adults. Immediate-release trazodone has been available for treatment of depression for many years, but is used mostly in low doses for its sedating effects.

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).

In our article on Drugs for Chronic Insomnia, we said there is little evidence that antidepressants such as trazodone, mirtazapine, or amitriptyline are effective in treating insomnia not associated with depression. We received a comment from a reader who has prescribed the tricyclic antidepressant amitriptyline for insomnia, particularly for patients with headache disorders, and finds that most patients are satisfied with the treatment.

Mirtazapine (mir taz a peen; Remeron - Organon) has been approved by the US Food and Drug Administration for treatment of depression. A tetracyclic piperazinoazepine, it is an analog of mianserin, an antidepressant available in Europe, but is structurally unrelated to antidepressants previously available in the USA.

Venlafaxine hydrochloride (Effexor - Wyeth-Ayerst) was recently approved by the US Food and Drug Administration for treatment of depression. An aminomethyl-benzyl- cyclohexanol, it is chemically related to bupropion (Wellbutrin).

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).

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

Many commonly used drugs can interfere with sexual function in both men and women, causing loss of libido, interfering with erection or ejaculation in men, and delaying or preventing orgasm in women. Drug-related effects on sexual function may be difficult to distinguish from the effects of depression or disease, but most are reversible when drug use is stopped and sometimes when dosage is decreased. Since many patients are reluctant to talk about sexual difficulties, physicians may wish to ask about the possibility of drug-induced sexual dysfunction, particularly when they have...

View the Inhibitors and Inducers of CYP Enzymes, P-Glycoprotein, and Other Transporters tables

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.