Medroxyprogesterone: Drug Information
1. Drug Name
Generic Name
Medroxyprogesterone
Brand Name(s)
- Pakistan: Provera
- India: Deviry
- US: Provera, Depo-Provera
- UK: Provera, Depo-Provera
2. Pharmacological Class
Class
Progestin
Subclass
Derivative of progesterone
3. Mechanism of Action
Medroxyprogesterone is a progestin hormone that primarily acts by inhibiting the secretion of gonadotropins (LH and FSH) by the pituitary gland. This prevents follicular maturation and ovulation.
4. Indications
Primary Indications
- Menstrual disorders: Treatment of abnormal uterine bleeding due to hormonal imbalance.
- Contraception: Prevention of pregnancy with the use of Depo-Provera injection.
Off-label Uses
- Endometrial hyperplasia
- Metastatic uterine or renal carcinoma
5. Dosage and Administration
Standard Dosage
For oral tablets (Provera):
- Menstrual disorders: 5-10 mg daily for 5-10 days starting on the 16th or 21st day of the menstrual cycle.
- Endometrial hyperplasia: 5-10 mg daily for 12-14 days per month, usually given in combination with estrogen replacement therapy.
For injectable suspension (Depo-Provera):
- Contraception: 150 mg intramuscularly every 3 months.
Route of Administration
Oral (tablets), Intramuscular (injection)
Special Populations
- Pediatric: Safety and efficacy not established in children.
- Geriatric: Use with caution, as elderly patients may be more susceptible to adverse effects.
6. Pharmacokinetics
Absorption
Well-absorbed after oral administration.
Distribution
Bioavailability is high. Protein binding is approximately 90%.
Metabolism
Metabolized extensively in the liver.
Excretion
Excreted in the urine.
Half-life
Elimination half-life is approximately 25-50 hours.
7. Contraindications
- Pregnancy (Category X)
- Undiagnosed vaginal bleeding
- History of thrombosis or thromboembolic disorders
- Known or suspected breast cancer
8. Warnings and Precautions
- Increased risk of thromboembolic disorders
- Increased risk of breast cancer
- Monitor for signs of depression
9. Side Effects
Common Side Effects
- Irregular vaginal bleeding
- Headache
- Weight changes
Serious Side Effects
- Thromboembolic disorders
- Breast cancer
- Depression
10. Drug Interactions
Major Interactions
- Warfarin
- Phenytoin
Moderate Interactions
- Rifampin
- Carbamazepine
Minor Interactions
- Ascorbic acid (Vitamin C)
- Acetaminophen
11. Pregnancy and Lactation
Pregnancy Category
Category X - Contraindicated during pregnancy.
Breastfeeding Considerations
Not recommended during breastfeeding. Small amounts of medroxyprogesterone may pass into breast milk.
12. Patient Counseling Information
- Follow the prescribed dosing schedule carefully.
- Report any unusual bleeding or symptoms immediately.
- Discuss contraceptive options and potential side effects with your healthcare provider.