Update on medical abortion

How to take MA medications

Mifepristone, a potent antiprogesterone, is taken first as a 200-mg oral tablet, administered with a glass of water. It begins the MA process by causing the endometrial lining to break down and the products of pregnancy to detach from the uterine lining. Mifepristone also promotes uterine contraction, softens the cervix, and sensitizes the myometrium to the effects of misoprostol.

Misoprostol is taken 1 to 2 days later. Patients typically prefer the buccal route, where two 200-μg tablets are placed in each cheek pouch for 30 minutes (2 tablets in the left cheek and 2 tablets in the right cheek for a total of 4 tablets), with any remaining fragments swallowed with water. It can also be administered vaginally or sublingually. Misoprostol is a synthetic prostaglandin that causes the uterus to contract and release the uterine contents.

Prescribing MA

In Canada, MA can be prescribed and dispensed by physicians or nurse practitioners, and dispensed by pharmacists. It is not necessary to supervise administration.

Before a prescription is written, the pregnancy should be confirmed using an in-office pregnancy test and the gestational age calculated using the last menstrual period, a pelvic examination, or an ultrasound. Bloodwork should be completed to determine Rh immune globulin status. If the patient is Rh-negative and at least 49 days pregnant, she should receive an injection of immune globulin 24 hours before starting MA to minimize risk of Rh sensitization for future pregnancies. There is limited evidence for the use of Rh immune globulin before 49 days of pregnancy.³ Finally, an ectopic pregnancy should be ruled out either by ultrasound or clinical symptoms, risk factors, or β-human chorionic gonadotropin levels. A follow-up appointment 7 to 14 days after MA should include a clinical examination, ultrasound, or β-human chorionic gonadotropin measurement to confirm a successful abortion.

Contraindications to MA

Medical abortion has several contraindications, which can be reviewed with the patient using the Medical Abortion Charting Form from the Canadian Abortion Providers Support network (https://www.caps-cpca.ubc.ca/AnnokiUploadAuth.php/e/e0/Canadian_Resource_1_-_Medical_Abortion_Prescriber_Checklist_2018-07-11.pdf). Mifepristone should be avoided in patients with inherited porphyria, as it can cause a porphyria storm, leading to severe abdominal pain, chest pain, vomiting, and confusion.⁶ Mifepristone is also a potent antiglucocorticoid and should be avoided in patients with chronic adrenal failure or uncontrolled asthma. Patients taking long-term glucocorticoid therapy might require a higher glucocorticoid dose for a week after taking mifepristone. Patients taking anticoagulants, or who have blood disorders or severe anemia (hemoglobin level < 95 g/L), should use MA with caution, as blood loss is expected in MA. Medical abortion will not work for an ectopic pregnancy, and it should not be prescribed if a patient is at increased risk of ectopic pregnancy or has severe abdominal pain or vaginal bleeding. Finally, intrauterine devices increase the likelihood of ectopic pregnancy and should be removed before MA, once an ectopic pregnancy has been ruled out.

Drug interactions

There is little information on the clinical importance of drug interactions with MA. That said, mifepristone is metabolized by the CYP (cytochrome P450) 3A4 enzyme, and CYP 3A4 inducers such as phenytoin, rifampin, or St John’s wort might decrease the effectiveness of MA, leading to a higher likelihood of treatment failure. Inhibitors such as ketoconazole and grapefruit juice might increase the mifepristone side effects such as nausea. Food and antacids can decrease the bioavailability of oral misoprostol, but this should have little effect if it is administered by the buccal or vaginal route.

Patient education

Patients should know what to expect when they complete MA at home. Some patients can have bleeding after taking the mifepristone (step 1) but many do not feel anything at all. By comparison, within 3 hours of taking misoprostol (step 2), patients should expect bleeding heavier than menses. Patients should seek urgent care if they are soaking 2 sanitary pads per hour for more than 2 hours; if they are passing lemonsized tissues for more than 2 hours; or if the pain is unbearable or not improving with medication. Patients who do not have bleeding after misoprostol likely had either a treatment failure or are retaining the products of conception. Patients should be counseled on the potential for failure with MA and the potential need for a dilation and curettage procedure. Light bleeding can last an average of 2 weeks after MA, and only sanitary napkins should be used, not tampons or menstrual cups.

Cramps are often painful and patients can find relief from over-the-counter nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen. Some patients might also benefit from having a few doses of a prescription opioid. Some individuals might prefer to take the misoprostol in the evening to avoid heavy cramping during the daytime hours.

Misoprostol can cause nausea, diarrhea, dizziness, fever, and headaches within 2 to 4 hours of administration. Loperamide and dimenhydrinate can be recommended for symptom control. A fever of 38°C (100.4°F) or higher, and nausea, vomiting, diarrhea, dizziness, or weakness occurring more than 24 hours after misoprostol administration require emergency assessment for infection or toxic shock syndrome.

Finally, it is crucial that practitioners inquire about future contraception, as ovulation can occur 8 days after MA, and counsel on available contraception and pregnancy options. For example, hormonal contraceptive pills or the patch can be started when misoprostol is taken, or an intrauterine device can be inserted at the follow-up visit after MA.

Conclusion

Primary care practitioners are well positioned to provide patients with education and access to MA. The next time your patient requests MA, remember to educate them on what to expect, assess for contraindications, and plan for future contraception and follow-up.