Women's Health Specialists of St. Louis
Obstetrics and Gynecology

Articles - PMS

Most women will complain of some emotional or physical changes associated with their monthly cycle. Premenstrual syndrome, or PMS, is the recurrence of these symptoms during the five days before the menstrual period. The symptoms may include irritability, food cravings and breast tenderness, and may significantly interfere with occupational, social, and sexual function. Twenty to forty percent of women have symptoms which have significant impact on work and social performance. The definition of PMS varies among studies. The key to diagnosis is that the symptoms occur predictably within five days of the onset of the period, that the symptoms are consistent with PMS and not explained by other illness, and that the symptoms have an impact on social or professional performance. The symptoms should be relieved spontaneously within four days after the onset of the menstrual period. Between 2-10% of all women have severe symptoms of PMS that significantly interfere with work or social life by causing extreme change in mood, appetite, and fatigue to such an extent as to jeopardize work and relationships. This severe form of PMS is called Premenstrual Dysphoric Disorder, or PMDD. Both PMS and PMDD are caused by changes in the estrogen and progesterone levels and the effect on the chemical messengers (neurotransmitters) of the brain. Serotonin is a neurotransmitter that is affected by changes in sex hormones.

Most of the studies about PMS have been small, so there are few recommendations for the treatment of PMS. There is evidence however that dietary supplementation and exercise can be of benefit. In a randomized study, regular aerobic exercise was shown to reduce PMS symptoms. Dietary supplementation with 1200mg of calcium carbonate per day and/or 200-400mg of magnesium per day has been shown to reduce symptoms. Vitamin E 400-800 IU/day and oil of primrose have been shown to reduce breast tenderness. Craving for high carbohydrate foods is behavior that increases the levels of tryptophan which is a precursor to serotonin. Women with severe PMS however will find little relief of symptoms with these lifestyle modifications. Because serotonin levels are reduced in patients with PMS, the initial drug of choice is a "Selective serotonin reuptake inhibitor" (SSRI) called Fluoxetine. Fluoxetine is better known as Prozac. Prozac is most often used for the treatment depression. Because of the stigma associated with depression, fluoxetine is prescribed under the trade name of Sarafem for the treatment of PMS. The dose used to treat PMS is typically lower then the dose need for the treatment of depression. Fluoxetine works by helping to stabilize serotonin levels. The drug may be taken daily throughout the month or during the two weeks prior to the menstrual period. Oral contraceptive pills may also be used to reduce the fluctuation in sex hormones throughout the month and thereby reduce the symptoms of PMS. Other anti-anxiety drugs and drugs to suppress the release of hormones from the ovary can be used in severe cases of PMS or PMDD.

The take home message is that most women will notice changes in mood, fluid retention, and sexual desire with normal changes in hormones that occur throughout the menstrual cycle. In some cases, the symptoms are severe enough to warrant intervention. Intervention may include lifestyle modification with change in diet, exercise and dietary supplements. It may, in some cases, require medical intervention with a SSRI or oral contraceptive pills.