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.

Sertraline (Zoloft - Roerig), a serotonin reuptake inhibitor, was recently approved for marketing by the US Food and Drug Administration for treatment of depression. Another serotonin reuptake inhibitor, fluoxetine (Prozac), is prescribed more frequently in the USA than any other antidepressant (Medical Letter, 32:83, 1990).

The FDA has approved injection of onabotulinumtoxinA (Botox – Allergan) for prevention of headaches in adult patients with chronic migraine (≥15 headache days/month for ≥3 months). It is the first drug approved for treatment of this indication. Botox is also FDA-approved for treatment of upper limb spasticity, axillary hyperhidrosis, cervical dystonia, blepharospasm and strabismus, and for cosmetic reduction of wrinkles.

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.

Since the introduction of fluoxetine (Prozac - Medical Letter, 30:45, 1988), bupropion (Wellbutrin - Medical Letter, 31:97, 1989), sertraline (Zoloft - Medical Letter, 34:47, 1992) and paroxetine (Paxil - this issue), the choice of an antidepressant has become more difficult. Should these widely prescribed new drugs replace tricyclic antidepressants such as amitriptyline (Elavil, and others), imipramine (Tofranil, and others), or nortriptyline (Aventyl, and others) for treatment of most patients with depression?

Gabapentin (Neurontin - Pfizer), which has been available in the US since 1994, is approved by the FDA only for treatment of partial epilepsy and postherpetic neuralgia, but is widely used off-label for a number of other indications, especially neuropathic pain syndromes. According to one report, among Medicaid recipients in Florida receiving gabapentin, 71% of prescriptions were for chronic pain and 8% for seizures and neuralgia ("The Pink Sheet" February 2, 2004; 66:30).

View the Comparison Table: Some Drugs for Migraine Prevention in Adults

View Figure: Treatments for Irritable Bowel Syndrome (IBS) in Adults

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).

Pentosan polysulfate sodium (Elmiron - Baker Norton), a semi-synthetic mucopolysaccharide structurally similar to heparin, has been approved by the US Food and Drug Administration for oral treatment of interstitial cystitis.