Objectives: To compare the effect of Foeniculum vulgare variety dulce (Sweet Fennel) vs. mefenamic acid for the treatment of primary dysmenorrhea.
Methods: A cohort of seventy women, 15-24 years old from a local university and high-school, who complained of dysmenorrhea were enrolled in this study. Ten cases were excluded due to evidence of secondary dysmenorrhea. The remaining 60 patients were graded mild, moderate and severe on the basis of a verbal multidimensional scoring system. Thirty patients with mild dysmenorrhea were also excluded from the study. Each of the 30 cases with moderate to severe dysmenorrhea was evaluated for three cycles. In the first cycle no medication was given (control cycle), in the second cycle the cases were treated by mefenamic acid (250 mg q6h orally) and in the third cycle, essence of Fennel's fruit with 2% concentration (25 drops q4h orally), was prescribed at the beginning of the cycle. These cycles were compared day by day for the effect, potency, time of initiation of action and also complications associated with each treatment modality, by using a self-scoring system. Intensity of pain was reported by using a 10-point linear analog technique. Statistical analyses were performed by the independent sample t-test, paired t-test and repeated measurement analysis method.
Results: In the study group the mean age of menarche was 12.5+/-1.3 years, the mean duration of menstruation was 6.6+/-1.4 days with the mean cycle days of 27+/-3. The findings observed during menses were as follows: headache in 26.7%, nausea in 63.3%, vomiting in 23.3%, diarrhea in 33.3%, fatigue in 93.3% and leaving the daily tasks undone was reported in 86.9% of the cases. Both of the drugs effectively relieved menstrual pain as compared with the control cycles (P<0.001). The mean duration of initiation of action was 67.5+/-46.06 min for mefenamic acid and 75+/-48.9 min for fennel. The difference was not statistically significant (P=0.57). Mefenamic acid had a more potent effect than fennel on the second and third menstrual days (P<0.05), however, the difference on the other days was not significant. No complication was reported in mefenamic acid treated cycles, but five cases (16.6%) withdrew from the study due to fennel's odor and one case (3.11%) reported a mild increase in the amount of her menstrual flow.
Conclusions: The essence of fennel can be used as a safe and effective herbal drug for primary dysmenorrhea, however, it may have a lower potency than mefenamic acid in the dosages used for this study.