Dienogest Versus Luteal Phase Fluoxetine in the Management of Premenstrual Syndrome: A Randomized Double Blind Placebo Controlled Trial

Premenstrual syndrome (PMS) manifests with distressing physical, behavioral and psychological symptoms, in the absence of organic or underlying psychiatric disease, which regularly recur during luteal phase of each menstrual cycle and disappear or significantly improve by the end of menstruation. Approximately 85-90 % of women may experience premenstrual emotional and physical changes in their reproductive age and the prevalence of severe PMS ranges from 3% to 8%.

The etiology of PMS is unknown but cyclical ovarian activity and the effect of estradiol and progesterone on serotonin and gamma-amino butyric acid are key factors. Absence of PMS before puberty, in pregnancy and after the menopause supports a role of cyclical ovarian activity in PMS etiology. PMS symptoms include psychological symptoms like mood swings, irritability, depression and feeling out of control; physical symptoms like breast tenderness, bloating and headaches; and behavioral symptoms like reduced visuospatial and cognitive ability. To diagnose PMS, symptoms should be recorded prospectively over two cycles using a symptom diary. Several symptom diaries exist but the Daily Record of Severity of Problems (DRSP) is reliable and simple for patients.

There is increasing evidence that serotonin may be important in the pathogenesis of PMS. A number of selective serotonin reuptake inhibitors have been used to treat PMS. Fluoxetine at was found to significantly reduce symptoms of tension, irritability and dysphoria, as well as physical symptoms compared with placebo, as measured by visual analogue scales. Luteal phase sertraline was found effective in the management of severe PMS.

Historically, treatment with progesterone was based on the hypothesis that in PMS sufferers, the ratio of progesterone and its derivatives to other hormones was lower than is usual in women. This allowed oestrogens to cause water retention, because there was insufficient progesterone to oppose them.

Gama amino butyric acid (GABA) produced by inhibitory neurons calms symptoms of anxiety, irritability and aggression. Part of the receptors, called GABA(A) on the neurone surface, necessary for GABA to have its effect, cannot be made without the break-down products of progesterone. The occurrence of severe symptoms has been correlated with falling levels of progesterone metabolites. Therefore, progesterone could relieve the symptoms of PMS by preventing falling levels of progesterone metabolites and loss of GABA(A) enhancement.