By Albuquerque Journal Staff, Albuquerque Journal
People taking antidepressants often find that their mood lifts, but their sex life sinks.
Viagra might help -- in women as well as men, according to a couple of small-scale studies headed by Dr. H. George Nurnberg, professor of psychiatry at the University of New Mexico.
Nurnberg is halfway through a larger study on men and hopes to start another one soon with women. It's important to include women in the research, he said, since depression and panic disorder tends to strike women twice as often as men.
The research might open up a new way of looking at how sexual dysfunction is related to antidepressants. On the face of it, it doesn't seem to make sense that sexual dysfunction caused by antidepressants, which work on brain chemicals, would be helped by Viagra, which works on relaxation of smooth muscles and opening up blood flow to the genitals.
Yet a study of nine women taking antidepressant medication and suffering side effects of reduced orgasms or no orgasms during sexual activity showed that Viagra restored sexual function in all of them. That study, conducted at UNM and Texas Tech University in Amarillo, was published in the August issue of Psychiatric Services.
Four similar patients on antidepressants -- two men and two women -- also saw their sexual function restored after taking Viagra, according to a study at UNM by Nurnberg and others. It was published in the January issue of the Journal of Clinical Psychiatry.
"It really makes you think differently about assumptions of the way certain things work," he said. "I think the whole vascular effect (of antidepressants) was totally underemphasized in terms of its actual role."
Some antidepressants have shown signs of inhibiting nitric oxide, which plays a role in blood flow during sexual arousal, he said. Nitric oxide also plays a role in brain function, he added. Some antidepressants also can increase the level of the hormone prolactin, which inhibits sexual function, he said.
Serotonin itself might play a role. That chemical, which is associated with pleasurable feelings and is enhanced by many antidepressants, is carried by platelets in the blood throughout the body, Nurnberg said. Serotonin leaking out of platelets, he added, can cause vascular and muscular spasms.
But while researchers can't say exactly why Viagra would help counter sexual dysfunction caused by antidepressants, they are pursuing further studies to explore the connection.
Nurnberg said UNM is more than halfway through a placebo-controlled, double-blind study, along with the University of Arizona and Harvard, on 90 men suffering sexual problems while taking antidepressants. He added that he is hoping to start a parallel trial with women.
During the course of the trial, participants might be taken off Viagra for a period of time to see if the sexual problems have been resolved or if people still need it to generate arousal and orgasm.
"No studies have been done on the course of the sexual dysfunction," Nurnberg said. In other words, does the side effect of antidepressants eventually go away on its own, or does it continue as long as the person is taking the drug?
Finding a way to counter this side effect can help with treatment of the actual depression, Nurnberg said. To get long-range help with their depression, people need to continue taking antidepressants for six to nine months after they feel better, he said.
Yet, he said, 60 percent of patients don't fill more than three prescriptions for the drug; a prescription usually covers enough pills for a month. Twenty-five percent don't finish treatment with the same antidepressant they started with; most of them switch because of problems with side effects, Nurnberg said.
UNM is looking for more volunteers for its studies. They must be between 18 and 55 years old and taking antidepressants, Nurnberg said. Their sexual dysfunction must not have occurred before they became depressed or started taking antidepressants, he said. They need to be physically healthy, with no heart disease that requires them to take organic nitrates, such as nitroglycerin. People on nitroglycerin can suffer dangerously low blood pressure when they take Viagra.
