Magestron (medroxyprogesterone acetate): Uses, Dosage & Side Effects

What it's for (Indications)

Used for contraception (including in women for whom other methods are contraindicated) and for the treatment of irregular menstrual periods and endometriosis-associated pain.

Dosage Information

Type	Guideline
Standard	Administration is to be performed by a healthcare professional. Prior to the first injection, pregnancy must be confirmed as absent. For contraception, the initial injection is typically given within 5 days from the start of menstruation. The injection is administered approximately every 3 months (12 to 14 weeks). Specifics depend on the formulation: the intramuscular formulation (e.g., Depo-Provera) is injected into the muscle of the buttock or upper arm; for the subcutaneous formulation (e.g., Depo-subQ Provera 104), 104 mg is administered subcutaneously into the anterior thigh or abdomen. If an injection is missed after 3 months from the previous dose, there is a high risk of pregnancy, and alternative contraception (e.g., condoms) should be used. Use for longer than 2 years is generally not recommended due to its impact on bone mineral density, unless other contraceptive methods or medical therapies for endometriosis-associated pain are inadequate.

Type

Guideline

Standard

Administration is to be performed by a healthcare professional. Prior to the first injection, pregnancy must be confirmed as absent. For contraception, the initial injection is typically given within 5 days from the start of menstruation. The injection is administered approximately every 3 months (12 to 14 weeks). Specifics depend on the formulation: the intramuscular formulation (e.g., Depo-Provera) is injected into the muscle of the buttock or upper arm; for the subcutaneous formulation (e.g., Depo-subQ Provera 104), 104 mg is administered subcutaneously into the anterior thigh or abdomen. If an injection is missed after 3 months from the previous dose, there is a high risk of pregnancy, and alternative contraception (e.g., condoms) should be used. Use for longer than 2 years is generally not recommended due to its impact on bone mineral density, unless other contraceptive methods or medical therapies for endometriosis-associated pain are inadequate.

Safety & Warnings

Common Side Effects

Common side effects include dysfunctional uterine bleeding (irregular, prolonged, heavy vaginal bleeding, or amenorrhea), headache, increased weight, and injection site reactions.
More serious or notable side effects include loss of bone mineral density, arterial and venous thromboembolic disorders, anaphylaxis, fluid retention, delayed return of ovulation or fertility (infertility on continuous use), and depression.

Serious Warnings

Black Box Warning: WARNING: LOSS OF BONE MINERAL DENSITY. Women who use medroxyprogesterone acetate may lose significant bone mineral density. Bone loss is greater with increasing duration of use and may not be completely reversible. It is unknown if use during adolescence or early adulthood, a critical period of bone accretion, will reduce peak bone mass and increase the risk for osteoporotic fracture in later life.
Patients should inform their doctor about their complete medical history, especially concerning bleeding disorders, clotting disorders, stroke, heart attack, liver impairment, undiagnosed abnormal vaginal bleeding, severe depression, or diabetes.
Use may lead to significant loss of bone mineral density, with greater loss seen with increasing duration of use; long-term use (over 2 years) is generally not recommended unless other birth control methods or medical therapies are considered inadequate.
Other warnings include arterial and venous thromboembolic disorders, anaphylaxis, fluid retention, and delayed return of fertility after discontinuation.
Medroxyprogesterone acetate is unsafe for use in patients with significant liver disease.
Safety and effectiveness in kidney patients are undetermined, and alcohol consumption should be limited.
This medicine may cause sleepiness and dizziness; therefore, driving should be avoided if these symptoms occur.

How it Works (Mechanism of Action)

Medroxyprogesterone acetate inhibits the secretion of gonadotropins, which primarily prevents follicular maturation and ovulation, and causes thickening of cervical mucus. These actions contribute to its contraceptive effect. Suppression of serum estradiol concentrations is likely responsible for the therapeutic effect on endometriosis-associated pain.