Overview
11 DESCRIPTION Medroxyprogesterone acetate injectable suspension, USP, a contraceptive injection, contains medroxyprogesterone acetate, USP a derivative of progesterone, as its active ingredient. Medroxyprogesterone acetate is active by the parenteral and oral routes of administration. It is a white or almost white, crystalline powder that is stable in air and that melts between 205°C and 209°C.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Medroxyprogesterone acetate (MPA) injectable suspension, 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. 12.2 Pharmacodynamics No specific pharmacodynamic studies were conducted with medroxyprogesterone acetate injectable suspension. 12.3 Pharmacokinetics Absorption Following a single 150 mg IM dose of medroxyprogesterone acetate injectable suspension in eight women between the ages of 28 and 36 years old, medroxyprogesterone acetate concentrations, measured by an extracted radioimmunoassay procedure, increase for approximately 3 weeks to reach peak plasma concentrations of 1 to 7 ng/mL.
Indications
- 1 INDICATIONS AND USAGE Medroxyprogesterone acetate injectable suspension is indicated for use by females of reproductive potential to prevent pregnancy. Limitations of Use: The use of medroxyprogesterone acetate injectable suspension is not recommended as a long-term (i.e., longer than 2 years) birth control method unless other options are considered inadequate [see Dosage and Administration (2.1) and Warnings and Precautions (5.1)]. Medroxyprogesterone acetate is a progestin indicated for use by females of reproductive potential to prevent pregnancy.
Common Doses
- 150 mg
- 1 mL
Dosage
2 DOSAGE AND ADMINISTRATION The recommended dose is 150 mg of medroxyprogesterone acetate injectable suspension every 3 months (13 weeks) administered by deep, intramuscular (IM) injection in the gluteal or deltoid muscle. (2.1) 2.1 Prevention of Pregnancy The 1 mL prefilled syringe of medroxyprogesterone acetate injectable suspension should be vigorously shaken just before use to ensure that the dose being administered represents a uniform suspension.
Black Box Warning
WARNING: LOSS OF BONE MINERAL DENSITY Women who use medroxyprogesterone acetate injectable suspension may lose significant bone mineral density. Bone loss is greater with increasing duration of use and may not be completely reversible [see Warnings and Precautions (5.1)] . It is unknown if use of medroxyprogesterone acetate injectable suspension 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 [see Warnings and Precautions (5.1)] .
Contraindications
- 4 CONTRAINDICATIONS The use of medroxyprogesterone acetate injectable suspension is contraindicated in the following conditions: Known or suspected pregnancy or as a diagnostic test for pregnancy. Active thrombophlebitis, or current or past history of thromboembolic disorders, or cerebral vascular disease [ see Warnings and Precautions ( 5.2 ) ]. Known or suspected malignancy of breast [ see Warnings and Precautions ( 5.3 ) ]. Known hypersensitivity to medroxyprogesterone acetate injectable suspension or any of its other ingredients [ see Warnings and Precautions ( 5.5 ) ].
Side Effects
- 6 ADVERSE REACTIONS The following important adverse reactions observed with the use of medroxyprogesterone acetate injectable suspension are discussed in greater detail in the Warnings and Precautions section ( 5 ): Loss of Bone Mineral Density [ see Warnings and Precautions ( 5.1 ) ] Thromboembolic disease [ see Warnings and Precautions ( 5.2 ) ] Breast Cancer [ see Warnings and Precautions ( 5.3 ) ] Anaphylaxis and Anaphylactoid Reactions [ see Warnings and Precautions ( 5.5 ) ] Bleeding Irregularities [ see Warnings and Precautions ( 5. 10) ] Weight Gain [ see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS Drugs or herbal products that induce certain enzymes, including CYP3A4, may decrease the effectiveness of contraceptive drug products. Counsel patients to use a back-up method or alternative method of contraception when enzyme inducers are used with medroxyprogesterone acetate injectable suspension. ( 7.1 ) 7.1 Changes in Contraceptive Effectiveness Associated With Co-Administration of Other Products If a woman on hormonal contraceptives takes a drug or herbal product that induces enzymes, including CYP3A4, that metabolize contraceptive hormones, counsel her to use...