It’s called premenstrual syndrome, or PMS, and every woman who has had a menstrual period knows what I’m talking about because it has happened to them. It can be mild or severe. It begins a few days to two weeks before her monthly period, and is a group of emotional and physical symptoms that make a woman miserable. Mood swings, crying, fatigue, irritability, and insomnia, plus bloating, breast tenderness, headaches, cravings, or loss of appetite are common symptoms. It varies in duration and severity, but is universally unpleasant.
PMS is very difficult to treat. The symptoms occur right before the onset of a period and last only a few days to a week. Ideally, the patient could take medication only during the time of symptoms. But the drugs of choice are SSRI’s like Prozac, Zoloft, Celexa, and Lexapro, and they can take a week or longer to reach therapeutic levels. They wouldn’t take effect until after the symptoms ended. So, until recently, patients were required to take medication every day of the month.
However, recent guidelines from the American College of Obstetrics and Gynecology (ACOG) have changed the protocol. They now say that intermittent dosing of SSRI’s daily starting 1 week before a period and ending 3 days after onset of the period is just as effective as continuous dosing. This regimen is now the preferred treatment.
My concerns are will the SSRI reach a therapeutic level enough to be effective and will the patient remember to start the drug a week before her period begins. Intermittent dosing is a good method, but the pharmacokinetics of SSRI’s may not allow it to succeed.
Reference: AFP Clinical Answers “Is intermittent dosing of SSRIs an acceptable alternative to continuous dosing in premenstrual disorders?” Am Fam Phys 2025 December;112(6):606.
