Low-doses of common antidepressant medication could provide a safe and fast-acting means of treating menstrual cycle-linked symptoms, according to Thelma Lovick of the University of Bristol.
Several selective serotonin reuptake inhibitors (SSRIs) like fluoxetine can raise brain concentrations of allopregnanolone, a metabolite of the hormone progesterone.
“[I]t is becoming clear that the name SSRI is in some sense a misnomer, since evidence is now accumulating to indicate that these compounds are far from selective exclusively for serotonin reuptake,” Lovick remarked in her article, published May 23 in the Journal of Psychopharmacology.
The rapid decrease of allopregnanolone in the brain during the luteal phase of the menstrual cycle has been linked to premenstrual syndrome and other disorders.
This could explain why SSRIs are frequently used to treat severe PMS and premenstrual dysphoric disorder (PMDD) symptoms. Research has found the drugs are “highly effective in treating the premenstrual symptoms.”
“Given the undisputed steroid-enhancing properties of fluoxetine, it is perhaps surprising that this aspect of its therapeutic potential has been realized only slowly,” Lovick wrote in her article.
The antidepressant drugs potentially offset the drop of allopregnanolone levels, preventing rapid withdrawal from the hormone, she explained. The dose of SSRIs needed to produce this effect is less than the dose needed for the drugs to produce their antidepressant effects.
“This action of fluoxetine can be achieved at doses far below the threshold for interaction with 5-HT [serotonin] systems, which are the target in antidepressant therapy,” Lovick said. “When translated into the clinical context, these findings suggest that current prescribing practice on SSRIs for PMS in women may not be optimal.”