Low doses of anti-depressants like fluoxetine (Prozac) can help in preventing symptoms of premenstrual syndrome (PMS), according to scientists from the University of Bristol, UCL and the University of Sao Paolo-Ribeiro Preto in Brazil.
Up to 80 percent of women suffer from PMS, with symptoms such as anxiety, irritability, fatigue, sleep deprivation and increased pain sensitivity. Towards the end of the menstrual cycle there is decreased secretion of the ovarian sex steroid hormone progesterone. Decline in progesterone leads to decline in its breakdown product allopregnanolone, which acts in the brain as a potent sedative and tranquilizing agent. This appears to trigger PMS.
AdvertisementMice studies have shown that short term treatment with low doses of the anti-depressants such as fluoxetine can inhibit a specific enzyme in the brain, which deactivates allopregnanolone, therefore maintaining the chemical balance of this in-built tranquilizer in the brain, and could be used to alleviate symptoms of progesterone withdrawal such as PMS and possibly also postnatal depression. It also blocked the increase in excitability of brain circuits involved in mediating the stress and fear responses that normally occur during this phase of the cycle.
The effective dose of fluoxetine was well below that needed to produce antidepressant effects and this effect was seen within hours of administration, unlike the two to three weeks of treatment normally needed when fluoxetine is used to treat depression.
Dr Lovick, from the School of Physiology and Pharmacology at the University of Bristol said, "The work is important because it introduces the possibility for targeted, intermittent therapy for PMS in women, with minimal side effects."