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Randomised trial, 1997

Does taking fluoxetine only during the premenstrual period work as well as taking it every day?

Both daily and premenstrual-only fluoxetine were effective for PMDD. Intermittent dosing appears to work nearly as well as daily dosing while causing fewer side effects.

Moderate study design 48 women with confirmed PMDD: 24 with a history of mood disorders or alcoholism, and 24 with no psychiatric history

What they did

Researchers compared two ways of taking fluoxetine in 48 women with PMDD. One group of 24 took it every day at 20 mg, and another group of 24 took 20 mg for 14 days before their period each month. Both groups took medication for 3 menstrual cycles.

What they found

In the daily group, 16 of 24 women (66.7%) responded well to treatment. In the premenstrual-only group, 18 of 24 women (75.0%) responded well. The intermittent group had mostly no side effects.

What it means for you

Taking fluoxetine only during the premenstrual phase may be just as effective as daily dosing and causes fewer unwanted effects, which could appeal to women who prefer shorter-term treatment. The study only looked at 3 menstrual cycles and one dose of fluoxetine.

24

women per treatment group

75.0%

response rate with intermittent dosing

66.7%

response rate with daily dosing

About the study

Original title
Intermittent fluoxetine dosing in the treatment of women with premenstrual dysphoria
Authors
Steiner M, Korzekwa M, Lamont J et al.
Journal
Psychopharmacology bulletin
Year
1997
Study design
Randomised trial
Participants
24
What was tested
Fluoxetine 20 mg daily (24 women) versus fluoxetine 20 mg for 14 days before the period (24 women)

Topics