Randomised Comparative Trial of the Levonorgestrel Intrauterine System and Mefenamic Acid for the Treatment of Idiopathic Menorrhagia: A Multiple Analysis Using Total Menstrual Fluid Loss, Menstrual Blood Loss, and Pictorial Blood Loss Assessment Charts

Abstract

This paper presents a comparison of 2 management strategies for idiopathic menorrhagiathe levonorgestrel intrauterine system (LNG IUS) and the more commonly used oral mefenamic acid. The LNG IUS is a progesterone-impregnated intrauterine device that has been shown to reduce menstrual blood loss (MBL). Study subjects were chosen from 391 women who presented to The Luton and Dunstable Hospital NHS Trust in South Bedfordshire, U.K., between May 1996 and December 1998 with the complaint of heavy menstrual bleeding. Enrollment was offered to healthy women age 18 to 47 with menorrhagia, defined as menstrual blood loss of 80 mL or more in one cycle confirmed by the modified alkaline-hematin technique. Each subject maintained a menstrual diary and completed a pictorial blood loss assessment chart (PBAC) within 4 months of starting the trial. In addition, study subjects participated in an objective assessment of total menstrual fluid loss (TMFL), which involved measuring the increase in weight of all tampons and sanitary napkins used in one menstrual cycle. Fifty-one women met all inclusion criteria and were randomized to receive 500 mg oral mefenamic acid 3 times daily on days 1 to 4 of the menstrual cycle (n = 26) or to have insertion of an LNG IUS containing 52 mg levonorgestrel released at 20 μg per 24 hours (n = 25). The study period for each treatment method was 6 cycles. Overall, MBL, TMFL, and PBAC scores improved significantly for both treatment groups. However, compared with those in the mefenamic acid group, women in the LNG IUS group had significantly lower blood loss on all 3 measurements at each evaluation point of the study period (P >.001 for all). Improvements in scores for MBL, TMFL, and PBAC were significantly correlated over the study period (P <.001 for the correlation between MBL and TMFL, P =.0007 for correlation of MBL and PBAC, and P = 0002 for correlation of TMFL and PBAC). Overall, women with the LNG IUS experienced more adverse events, 2 of which were serious, over the course of the study than did women in the mefenamic acid group (158 vs 84). In one patient who developed severe hypertension, the LNG IUS was discovered in the endocervical canal and removed after 55 days. In a second woman, the LNG IUS was expelled after successful treatment for chlamydial endometritis.