Monograph: |
Gemeprost
Adverse Effects and Precautions
Gemeprost is given vaginally as pessaries and systemic adverse effects such as nausea, vomiting, and diarrhoea are relatively mild. Other reported adverse effects have included headache, muscle weakness, dizziness, flushing, chills, backache, dyspnoea, chest pain, palpitations, and mild pyrexia. Vaginal bleeding and mild uterine pain may occur.
Uterine rupture has been reported rarely, most commonly in multiparous women and in those with a history of uterine surgery. There have also been rare reports of severe hypotension and coronary spasm with subsequent myocardial infarction.
The effects of gemeprost on the fetus are not known. Once a prostaglandin has been given to terminate pregnancy it is essential that termination take place; if the prostaglandin is unsuccessful other measures should be used.
Gemeprost should be used with caution in patients with obstructive airways disease, cardiovascular disease, raised intra-ocular pressure, cervicitis, or vaginitis. Blood pressure and pulse rate should be monitored after use; when given with mifepristone monitoring for 6 hours is recommended.
Incidence of adverse effects.
The incidence of vomiting (19 or 35%) and diarrhoea (12 or 19%) in 2 studies of patients treated with gemeprost pessaries was similar to that seen with other prostaglandins, but gemeprost was reported to cause less uterine pain. Like other prostaglandins used for termination of pregnancy it may occasionally produce hyperstimulation and uterine rupture.
Effects on the cardiovascular system.
Periods of ventricular standstill of up to 6 seconds were observed in a patient during treatment with gemeprost vaginal pessaries. The patient required temporary cardiac pacing, but no persistent cardiac rhythm disturbances were detected on follow-up. Severe cardiogenic shock due to vasospasm, and subsequent stroke, has been reported in a patient who had received gemeprost pessaries some hours earlier; myocardial infarction ensuing from coronary spasm was reported in a second patient.
Uses and Administration
Gemeprost is a synthetic analogue of alprostadil (prostaglandin E1). It is used to soften and dilate the cervix and as a uterine stimulant in the termination of pregnancy. In the first trimester, a pessary containing gemeprost 1 mg is inserted into the vagina 3 hours before surgery to ripen the cervix. Gemeprost may also be used for termination of pregnancy in the second trimester when a 1-mg pessary is inserted every 3 hours to a maximum of 5 pessaries. Should this course be ineffective one further course may be given after an interval of 24 hours. In the case of intra-uterine fetal death only one course of five pessaries should be given. Vaginal gemeprost is also used after oral mifepristone in the termination of pregnancy.
|