A comparison of isosorbide mononitrate, misoprostol and combination therapy for first trimester pre-operative cervical ripening : a randomised controlled trial

• Published in: BJOG : an international journal of obstetrics and gynaecology 2001-03, Vol.108 (3), p.276-280
• Main Authors: LEDINGHAM, Marie-Anne, THOMSON, Andrew J, LUNAN, C. Burnett, GREER, Ian A, NORMAN, Jane E
• Format: Article
• Language: English
• Subjects: Abortifacient Agents, Nonsteroidal - administration & dosage; Abortion, Induced - methods; Adult; Biological and medical sciences; Cervical Ripening - drug effects; Drug Therapy, Combination; Female; Genital system. Reproduction; Humans; Isosorbide Dinitrate - administration & dosage; Isosorbide Dinitrate - adverse effects; Isosorbide Dinitrate - analogs & derivatives; Medical sciences; Misoprostol - administration & dosage; Misoprostol - adverse effects; Nitric Oxide Donors - administration & dosage; Nitric Oxide Donors - adverse effects; Pharmacology. Drug treatments; Pregnancy; Treatment Outcome; Vasodilator Agents - administration & dosage; Vasodilator Agents - adverse effects
• ISSN: 1470-0328; 1471-0528
• DOI: 10.1016/S0306-5456(00)00041-3

To determine whether a combined therapy with isosorbide mononitrate (40mg) and misoprostol (400 microg) for pre-operative cervical ripening in the first trimester would result in improved clinical effectiveness, and fewer side effects compared with each agent used alone. Randomised controlled trial. Glasgow Royal Infirmary. Sixty-six primigravid women scheduled for suction termination of pregnancy. Women were randomly assigned to receive before surgery, per vaginam, isosorbide mononitrate 40 mg (n = 22), misoprostol 400 microg (n = 22) or both agents together [isosorbide mononitrate 40 mg and misoprostol 400 microg] (n = 22). 1. To assess the cumulative force required to dilate the cervix to 8 mm; 2. the onset of new symptoms before termination of pregnancy. The cervical resistance following combination therapy with isosorbide mononitrate and misoprostol was not significantly different than following misoprostol alone [24.5N vs 18.5N; median difference (95% CI) 19N (-22 to 49)]. Pre-treatment with misoprostol used alone resulted in a lower cervical resistance than isosorbide mononitrate alone (18.5N vs 39N, P = 0.04, Mann-Whitney U test). There was no difference in the number of women remaining asymptomatic following either isosorbide mononitrate or misoprostol or combination therapy [14/22 (64%) vs 11/21 (52%) vs 11/22 (50%), Fisher's exact test]. We have not shown any advantage of combining misoprostol with the nitric oxide donor isosorbide mononitrate compared with misoprostol alone for pre-operative cervical ripening in the first trimester.