A common complaint about the otherwise highly praised new antidepressant fluoxetine (Prozac) is that it reduces sexual interest and capacity. A new study suggests that patients with this problem may see an improvement if they switch to another antidepressant, bupropion (Wellbutrin).
Largely by placing advertisements in newspapers, researchers found 39 patients, about equally divided between the sexes, who had been taking fluoxetine and were concerned about delayed or infrequent orgasm and loss of sexual desire. After two drug-free weeks, they were switched to bupropion. Eight dropped out during the first month on the new drug because of recurring depression or side effects (agitation, nausea, constipation, headache). Of the remaining 31, 29 recovered their capacity for orgasm at least partially; 25 said their libido had increased and were much or very much more satisfied with their sexual functioning. Men and women were affected similarly. During the next four weeks another six patients dropped out, but 21 of the 25 who took bupropion for eight weeks recovered their capacity for orgasm and felt greater sexual satisfaction without becoming depressed again.
The authors admit that since there was no control group, both patients and investigators could have been responding to their hopes rather than to the change in medication. But they suggest a neurochemical explanation for the difference between the two drugs. Fluoxetine enhances the transmission of serotonin, which may inhibit orgasm; bupropion may influence noradrenergic neurons that have the opposite effect.
