Mifepristone

Drug Overview

Mifepristone is an antiprogestin medication primarily used for terminating early pregnancies and treating hormone-related conditions. This drug blocks progesterone receptors, preventing the endometrial lining from supporting embryo implantation, thereby inducing uterine contractions to expel tissue. Clinically, it is often combined with other medications such as misoprostol to enhance efficacy.

Additionally, mifepristone is used to treat conditions like uterine fibroids or endometriosis by inhibiting adrenal cortex hormone receptors, which can alleviate related symptoms. However, it must be used strictly under medical supervision due to its potent effects and potential for serious side effects.

Brand Names and Generic Name

The generic name of this medication is "Mifepristone." It may have different brand names in various regions, such as:

• RU-486 (original drug from France)
• Other brands depending on the pharmaceutical manufacturer

Generic versions are widely available in many markets, but it is essential to verify the legality and medical oversight before use.

Drug Classification

Mifepristone is classified as an "Antiprogestin." Its chemical structure resembles natural progesterone but can competitively bind to receptors, blocking normal hormonal action. This classification gives it unique therapeutic value in obstetrics and gynecology.

Indications

Main Uses

1. Termination of early pregnancy: suitable for pregnancies within 49 days of missed period, used in combination with other medications. 2. Treatment of uterine fibroids: to reduce excessive menstrual bleeding or uterine hemorrhage. 3. Other uses: such as treatment for endometriosis or certain hormone-related tumors.

Usage Restrictions

Restricted to prescription use after thorough medical evaluation. Self-medication is not advised. Candidates must meet specific physiological conditions, such as gestational age and normal uterine structure.

Common Side Effects

Mild reactions:

• Lower abdominal cramping or pain
• Vaginal bleeding or tissue expulsion
• Dizziness, nausea, and other gastrointestinal discomforts

These reactions are typically expected effects of the medication but require close monitoring for any worsening.

Serious side effects:

• Excessive bleeding leading to anemia
• Allergic reactions (rash, hives, difficulty breathing)
• Rare but severe complications such as uterine perforation

Immediate medical attention is necessary if these symptoms occur.

Warnings and Precautions

Contraindications:

• Pregnant women (except for pregnancy termination purposes)
• Patients with ectopic pregnancy
• Allergy to the medication components

Unsupervised use may lead to serious consequences.

This medication carries a black box warning. Prior confirmation of gestational age and uterine condition is required. Use in late pregnancy may increase the risk of uterine rupture. Breastfeeding women should consult a physician before use.

Drug Interactions

Concurrent use with the following drugs may affect efficacy or increase side effects:

• Anticoagulants (e.g., warfarin) may increase bleeding risk
• Antiepileptic drugs (e.g., phenytoin) may accelerate metabolism
• Steroids may reduce effectiveness

Always inform your healthcare provider about any prescription, over-the-counter, or herbal medications.

Dosage and Administration

Administration and dosage should strictly follow medical instructions:

• For pregnancy termination: usually combined with misoprostol in multiple doses
• For uterine fibroid treatment: dosage adjusted based on weight and condition

Initial doses should be administered under medical supervision with ultrasound follow-up.

The medication should be swallowed whole; do not chew or split tablets. Timing and dosage errors can lead to reduced efficacy or increased side effects. Do not adjust the medication plan independently.

Missed Dose Management

If a dose is missed:

• If within 2 hours, take immediately
• If close to the next scheduled dose, skip the missed dose

Never double the dose to compensate; contact your healthcare provider immediately.

Overdose Management

Overdose may cause severe bleeding, excessive uterine contractions, or electrolyte disturbances. Immediate actions include: 1. Lie flat with legs elevated 2. Seek medical attention immediately and inform the amount and timing of overdose. Medical teams may perform hemostasis or supportive treatments.

If signs of shock occur (such as sudden drop in blood pressure or altered consciousness), it is a medical emergency requiring urgent hospital care.

 

Frequently Asked Questions

What should I do if I experience severe abdominal pain or heavy bleeding after taking mifepristone?

If you experience intense abdominal pain or bleeding exceeding 2 pads per hour, seek medical attention immediately. Mild pain can be alleviated with warm compresses on the lower abdomen. During bleeding, use sanitary pads and change regularly. Do not self-medicate with painkillers; consult a doctor for appropriate treatment.

Does taking other hormonal medications (such as contraceptives) affect the efficacy of mifepristone?

Hormonal drugs may interfere with the mechanism of mifepristone. During treatment, avoid concurrent use of progestin-based contraceptives or certain other hormonal medications. If undergoing hormonal therapy, inform your doctor as dosage adjustments or alternative treatments may be necessary.

Can I engage in vigorous exercise or lift heavy objects during treatment?

Uterine contractions may increase bleeding risk. It is advisable to avoid lifting objects over 5 kg and strenuous activities for at least one week. Light activities like walking are permitted, but if dizziness or increased bleeding occurs, stop immediately and seek medical care.

What is the likelihood of incomplete uterine evacuation after medical abortion, and how can I confirm success?

Approximately 5-10% of cases may require follow-up curettage. Ultrasound examinations are typically used to confirm complete uterine evacuation, and serum hCG levels can serve as additional indicators. If bleeding persists beyond two weeks or fever develops, return to the clinic promptly.

Does mifepristone affect future fertility?

When used as directed, this medication does not cause long-term uterine damage or affect future pregnancy ability. However, severe uterine bleeding or infection during treatment may increase the risk of subsequent infertility. Strict adherence to medical advice and follow-up is essential.