It was thought Viagra does not help women with sexual arousal or enjoyment

But a new study suggests that Viagra could help certain women -- those who suffer the sexual side effects of antidepressants -- to achieve an orgasm.

Pfizer financed the study, which appears in The Journal of the American Medical Association.

The researchers compared the effects of authentic Viagra with a placebo in an eight-week study of 98 women who reported at least a month of sexual dysfunction from taking antidepressants.

They found that 72 percent of the women who took Viagra reported overall sexual improvement in a questionnaire that takes into account arousal, enjoyment and orgasm; 27 percent of those taking the placebo reported such gains.

During the study, women taking Viagra suffered headaches and indigestion at a higher rate than women taking the placebo.

The average age of the women in the study was 37, and none had entered menopause. Initial endocrine levels did not differ significantly between the groups, and the women agreed to try to have sex at least once a week. Previous studies, including those financed by Pfizer have not shown that Viagra works for women.

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