Psychiatrists may want to add sildenafil (Viagra) to their treatment armamentarium for sexual dysfunction. New studies show that the drug yields significant improvements in patients on SSRIs or with untreated depression.

An estimated 52 percent of men aged 40 to 70 years experience sexual problems, in particular erectile dysfunction (ED). Depression may cause ED or be a consequence of ED. SSRIs also can cause sexual dysfunction, which contributes to noncompliance and premature medication switching, said human sexuality expert Pierre Assalian, M.D., at the annual meeting of the Canadian Psychiatric Association last month in Victoria, British Columbia.

Although sildenafil is best known for the treatment of ED, researchers have found that the drug leads to improvements in other areas of male sexual dysfunction, including ejaculations and orgasms, according to Assalian, the director of the human sexuality unit and chief of psychiatry at Montreal General Hospital in Quebec.

He referred to a 1999 study showing that 66 percent of men on SSRIs had significant improvement in erectile and orgasmic function after taking between 5 mg and 200 mg of sildenafil for six to 24 weeks. Subjects were started on the lower dose, which was increased as needed and taken one hour before sex.

In contrast, 33 percent of the men on SSRIs and placebo had no change in those areas of sexual function, according to Assalian.

Women also suffer sexual side effects from SSRIs, including a lack of desire, arousal, and orgasm. An open trial of sildenafil in 14 depressed men and women showed that both experienced significant improvement in sexual functioning, said Assalian.

However, he cautioned that sildenafil should not be prescribed until after the patient has had an adequate trial on an SSRI. "Some patients have no interest in sex when they are depressed, and others may not have sexual dysfunction. If the patient’s interest increases, but his or her sexual functioning worsens, then it’s time to talk about options," said Assalian.

Because many patients with sexual dysfunction have comorbid depression, researchers have examined whether sildenafil is an effective and safe treatment for them, according to Assalian. A 1999 study of 146 depressed men found that 83 percent of the group treated with sildenafil had improved sexual functioning, compared with 17 percent of the men in the placebo group. The subjects were started on 25 mg of sildenafil, which they took one hour before having sex. The researchers increased the dosage up to 100 mg if lower doses were found to be ineffective over the 12-week trial.

The most common side effects were headache, flushing, and indigestion, noted Assalian.

Researchers also found that that 83 percent of the sildenafil group had a significant reduction in their mean scores on the Beck Depression Inventory and Hamilton Depression Rating Scale, according to Assalian.

He noted that the 146 subjects were diagnosed with a depressive disorder not otherwise specified in DSM-IV rather than major depression. Assalian commented that the depression might have improved as a consequence of improved sexual function.

Patients may prefer sildenafil, which is taken orally, to invasive methods available for treating sexual dysfunction such as mechanical devices, injections, and penile implants, said Assalian.

In addition, sildenafil’s reported side effects have resulted in minimal noncompliance, said Assalian. Sildenafil is contraindicated in men taking any type of nitrate therapy and should be used cautiously in men who have suffered a heart attack, stroke, or life-threatening arrhythmia or have high blood pressure, said Assalian.

Because sildenafil works only in response to sexual stimulation, Assalian recommends patients take 50 mg one hour before sexual activity.

Assalian urged psychiatrists to ask their men patients about sexual activity and functioning during the initial assessment and at appropriate intervals. "We should not accept sexual dysfunction as the norm and expect patients to bring it up. If left untreated, the problem can devastate a person’s self-esteem and cause marital friction and even divorce," said Assalian.

Because sexual dysfunction affects the patient’s partner, Assalian recommends couples counseling. "It’s important to demystify the problem so the woman doesn’t blame herself and think she is undesirable. It is also important to discuss treatment options with both partners. I have had a woman complain that since her partner took Viagra, he has forgotten about foreplay."

The studies that Assalian discussed were funded by Pfizer.