mifepristone + misoprostol: clinical use

Prescribing considerations

• Confirm pregnancy, gestational age and intrauterine location before prescribing.
• Ensure access to emergency assessment, surgical management, transfusion and resuscitation if needed.
• Arrange reliable follow-up to confirm complete abortion; bleeding alone does not establish success.
• Remove an intrauterine contraceptive device before treatment.
• Assess anaemia, coagulation disorders, cardiovascular risk, renal or hepatic impairment and malnutrition.
• Treat reproductive-tract infection before treatment and apply routine rhesus assessment and prophylaxis measures.
• Review corticosteroid therapy and clinically important CYP3A4 interactions.

Contraindications and cautions

• Unconfirmed pregnancy or pregnancy beyond the product’s licensed gestational limit
• Confirmed or suspected ectopic pregnancy
• Severe asthma uncontrolled by treatment
• Chronic adrenal failure
• Inherited porphyria
• Hypersensitivity to mifepristone, misoprostol, other prostaglandins or excipients

Monitoring

• Confirm completion using appropriate clinical, biochemical or ultrasound assessment.
• Assess persistent bleeding for incomplete abortion or previously unrecognised ectopic pregnancy.
• Investigate persistent pain, fever, pelvic tenderness or vaginal discharge for infection.
• Arrange specialist ultrasound monitoring if pregnancy continues.
• Ensure patients know how to recognise heavy bleeding, infection and severe skin reactions.

Clinical pharmacology

Mifepristone competitively blocks progesterone receptors, sensitises the myometrium to prostaglandins and has antiglucocorticoid activity. Misoprostol is converted to an active prostaglandin E1 analogue that promotes cervical relaxation and uterine contraction. Mifepristone is metabolised through CYP3A4 and is eliminated slowly.

Formulation and product differences

• The selected combipack contains an oral mifepristone tablet and misoprostol vaginal tablets.
• The misoprostol vaginal tablets should not be divided.
• Vaginal misoprostol in this product has different absorption from misoprostol products intended for other routes; formulations should not be substituted without specialist instruction.