medroxyprogesterone acetate (Medroxyprogesterone Acetate) tablet
[BARR LABORATORIES, INC.]
AUGUST 2001
21008720103
(Three Patient Information Leaflets Enclosed-Tear at Perforation)
Rx only
Medroxyprogesterone Acetate Tablets contain medroxyprogesterone acetate, which is a derivative of progesterone. It is a white to off-white, odorless, crystalline powder, stable in air, melting between 200 and 210°C. It is freely soluble in chloroform, soluble in acetone and in dioxane, sparingly soluble in alcohol and in methanol, slightly soluble in ether, and insoluble in water.
The chemical name for medroxyprogesterone acetate is Pregn-4-ene-3,20-dione, 17-(acetyloxy)-6-methyl-, (6α)-. The structural formula is:
C24H34O4 Molecular Weight: 386.53O mm
Each tablet, for oral administration, contains 2.5 mg, 5 mg or 10 mg of medroxyprogesterone acetate. In addition, each tablet contains the following inactive ingredients: crospovidone, lactose monohydrate, magnesium stearate, methylcellulose, pregelatinized starch, and sodium lauryl sulfate.
Medroxyprogesterone acetate (MPA), administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. Androgenic and anabolic effects have been noted, but the drug is apparently devoid of significant estrogenic activity. While parenterally administered MPA inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses.
The pharmacokinetics of MPA were determined in 20 postmenopausal women following a single-dose administration of eight Medroxyprogesterone Acetate Tablets 2.5 mg or a single administration of two medroxyprogesterone acetate tablets 10 mg under fasting conditions. In another study, the steady-state pharmacokinetics of MPA were determined under fasting conditions in 30 postmenopausal women following daily administration of one medroxyprogesterone acetate tablet 10 mg for 7 days. In both studies, MPA was quantitated in serum using a validated gas chromatography-mass spectrometry (GC-MS) method. Estimates of the pharmacokinetic parameters of MPA after single and multiple doses of medroxyprogesterone acetate tablets were highly variable and are summarized in Table 1.
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Tablet Strength |
Cmax (ng/mL) |
Tmax (h) |
Auc0-∞ (ng*h/mL) |
t½ (h) |
Vd/f (L) |
CL/f (mL/min) |
|
Single Dose | |||||||
2 x 10 mg | 1.01 (0.599) | 2.65 (1.41) | 6.95 (3.39) | 12.1 (3.49) |
78024 (47220) |
64110 (42662) |
|
8 x 2.5 mg | 0.805 (0.413) | 2.22 (1.39) | 5.62 (2.79) | 11.6 (2.81) |
62748 (40146) |
74123 (35126) |
|
Multiple Dose | |||||||
10 mg* | 0.71 (0.35) | 2.83 (1.83) | 6.01 (3.16) | 16.6 (15.0) |
40564 (38256) |
41963 (38402) |
No specific investigation on the absolute bioavailability of MPA in humans has been conducted. MPA is rapidly absorbed from the gastrointestinal tract, and maximum MPA concentrations are obtained between 2 to 4 hours after oral administration.
Administration of medroxyprogesterone acetate with food increases the bioavailability of MPA. A 10-mg dose of medroxyprogesterone acetate, taken immediately before or after a meal, increased MPA Cmax(50 to 70%) and AUC (18 to 33%).
The half-life of MPA was not changed with food.
MPA is approximately 90% protein bound, primarily to albumin; no MPA binding occurs with sex-hormone binding globulin. The unbound MPA modulates pharmacologic responses.
Following oral dosing, MPA is extensively metabolized in the liver via ring A and/or side-chain hydroxylation, with subsequent conjugation and elimination in the urine. At least 16 MPA metabolites have been identified.
Most MPA metabolites are excreted in the urine as glucuronide conjugates with only minor amounts excreted as sulfates. Mean percent dose excreted in the 24-hour urine of patients with fatty liver as intact MPA after a 10-mg or 100-mg dose was 7.3% and 6.4%, respectively.
The pharmacokinetics of MPA in patients with varying degrees of renal insufficiency have not been investigated. The renal clearance of MPA is negligible and a decrease in total body clearance is not expected in patients with renal insufficiency.
MPA is almost exclusively eliminated via hepatic metabolism. In 14 patients with advanced liver disease, MPA disposition was significantly altered (reduced elimination). As such, medroxyprogesterone acetate is contraindicated in patients with severe hepatic disease (see CONTRAINDICATIONS). However, for patients with mild-moderate degree of hepatic impairment, a lower dose of medroxyprogesterone acetate or a less frequent administration should be considered.
No formal pharmacokinetic drug-drug interaction studies have been conducted with medroxyprogesterone acetate. However, published literature indicates that coadministration of conjugated estrogens with MPA does not affect the pharmacokinetic profile of MPA; similarly, MPA does not affect the pharmacokinetic profile of the conjugated or unconjugated estrogens. Literature data also indicate that concomitant administration with aminoglutethimide would significantly reduce serum concentrations of MPA, likely by increasing the clearance of the drug.
The use of unopposed estrogen therapy has been associated with an increased risk of endometrial hyperplasia, a possible precursor of endometrial carcinoma.1 The incidence of estrogen-associated endometrial hyperplasia and endometrial cancer was assessed in two large, long-term, randomized clinical trials. The histological results of the clinical studies indicate that the addition of medroxyprogesterone acetate to an estrogen replacement regimen for 12 to 14 days per cycle reduces the incidence of endometrial hyperplasia in women with intact uteri. The addition of a progestin to 0.625 mg conjugated estrogen has not been shown to interfere with the efficacy of 0.625 mg conjugated estrogen for its approved indications.1-3
A 3-year, double-blind, placebo-controlled study of nonhysterectomized, postmenopausal women between the ages of 45 and 64 years were randomized to receive placebo, conjugated estrogen only, or conjugated estrogen plus cyclic medroxyprogesterone acetate. The treatment group receiving 10 mg medroxyprogesterone acetate plus 0.625 mg conjugated estrogens showed a significantly lower rate of hyperplasia in comparison to the group given 0.625 mg conjugated estrogens only. The 3-year histological results are summarized in Table 2.
* Includes most extreme abnormal result | |||
Histological Results |
Placebo (n=119) |
CEE* (n=119) |
Medroxyprogesterone |
Normal/No hyperplasia (%) |
116 (97) | 45 (38) | 112 (95) |
Simple (cystic) hyperplasia (%) |
1 (1) | 33 (28) | 4 (3) |
Complex (adenomatous) hyperplasia (%) |
1 (1) | 27 (22) | 2 (2) |
Atypia(%) | 0 | 14 (12) | 0 |
Adenocarcinoma (%) |
1 (1) | 0 | 0 |
In a second study, postmenopausal women between the ages of 45 and 65 years were enrolled in a 1-year, double-blind study. All patients received conjugated estrogen 0.625 mg every day of a 28-day cycle, and were randomized to receive cyclic MPA 5 mg, cyclic MPA 10 mg, or conjugated estrogen only. The treatment groups receiving MPA 5 or 10 mg plus conjugated estrogens showed a significantly lower rate of hyperplasia in comparison to the group given conjugated estrogens only. The incidence of endometrial hyperplasia is shown in Table 3.
CEE* | MPA† + CEE* | ||
(n=283) |
MPA 5 mg (n=277) |
MPA 10 mg (n=272) |
|
Cystic hyperplasia (%) |
55 (19) | 3 (1) | 0 |
Adenomatous hyperplasia without atypia |
2 (1) | 0 | 0 |
Medroxyprogesterone Acetate Tablets are indicated for secondary amenorrhea and for abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as fibroids or uterine cancer. Medroxyprogesterone Acetate Tablets are also indicated to reduce the incidence of endometrial hyperplasia in nonhysterectomized postmenopausal women receiving 0.625 mg conjugated estrogen.
Long-term intramuscular administration of medroxyprogesterone acetate has been shown to produce mammary tumors in beagle dogs. There was no evidence of a carcinogenic effect associated with the oral administration of medroxyprogesterone to rats and mice. Medroxyprogesterone acetate was not mutagenic in a battery of in vitro or in vivo genetic toxicity assays.
Medroxyprogesterone acetate at high doses is an antifertility drug and high doses would be expected to impair fertility until the cessation of treatment.
See Patient Information at the end of the brochure.
Medroxyprogesterone acetate tablets are contraindicated during pregnancy. Several reports suggest an association between intrauterine exposure to progestational drugs in the first trimester of pregnancy and genital abnormalities in male and female fetuses. The risk of hypospadias in male fetuses may be doubled with exposure to these drugs. Some progestational drugs induce mild virilization of the external genitalia of female fetuses.
The administration of any drug to nursing mothers should be done only when clearly necessary since many drugs are excreted in human milk. Detectable amounts of progestin have been identified in the milk of nursing mothers receiving progestins. The effect of this on the nursing infant has not been determined.
The safety and effectiveness of medroxyprogesterone acetate tablets in pediatric patients has not been established.
Breast tenderness or galactorrhea has been reported.
Sensitivity reactions consisting of urticaria, pruritus, edema and generalized rash have occurred. Acne, alopecia and hirsutism have been reported.
Thromboembolic phenomena including thrombophlebitis and pulmonary embolism have been reported.
The following adverse reactions have been observed in women taking progestins, including medroxyprogesterone acetate tablets:
breakthrough bleeding
cholestatic jaundice
spotting
anaphylactoid reactions and anaphylaxis rash (allergic) with and without pruritus
change in menstrual flow
amenorrhea
edema
change in weight (increase or decrease)
mental depression
pyrexia
changes in cervical erosion and cervical secretions
insomnia
nausea
somnolence
Although available evidence is suggestive of an association, such a relationship has been neither confirmed nor refuted for the following serious adverse reactions:
neuro-ocular lesions, e.g., retinal thrombosis and optic neuritis.
The following adverse reactions have been observed in patients receiving estrogen-progestin combination drugs:
rise in blood pressure in susceptible individuals
fatigue
backache
hirsutism
premenstrual-like syndrome
loss of scalp hair
erythema multiforme
changes in libido
erythema nodosum
hemorrhagic eruption
changes in appetite
cystitis-like syndrome
headache
itching
nervousness
dizziness
The following laboratory results may be altered by the use of estrogen-progestin combination drugs:
Increased sulfobromophthalein retention and other hepatic function tests.
Coagulation tests: increase in prothrombin factors VII, VIII, IX and X.
Metyrapone test.
Pregnanediol determination.
Thyroid function: increase in PBI, and butanol extractable protein bound iodine and decrease in T3 uptake values.
Medroxyprogesterone acetate tablets may be given in dosages of 5 or 10 mg daily for 5 to 10 days. A dose for inducing an optimum secretory transformation of an endometrium that has been adequately primed with either endogenous or exogenous estrogen is 10 mg of medroxyprogesterone acetate daily for 10 days. In cases of secondary amenorrhea, therapy may be started at any time. Progestin withdrawal bleeding usually occurs within three to seven days after discontinuing medroxyprogesterone therapy.
Beginning on the calculated 16th or 21st day of the menstrual cycle, 5 or 10 mg of medroxyprogesterone acetate may be given daily for 5 to 10 days. To produce an optimum secretory transformation of an endometrium that has been adequately primed with either endogenous or exogenous estrogen, 10 mg of medroxyprogesterone acetate daily for 10 days beginning on the 16th day of the cycle is suggested. Progestin withdrawal bleeding usually occurs within three to seven days after discontinuing therapy with medroxyprogesterone. Patients with a past history of recurrent episodes of abnormal uterine bleeding may benefit from planned menstrual cycling with medroxyprogesterone.
Medroxyprogesterone acetate tablets may be given in dosages of 5 or 10 mg daily for 12 to 14 consecutive days per month, either beginning on the 1st day of the cycle or the 16th day of the cycle.
Medroxyprogesterone Acetate Tablets, USP are available as:
2.5 mg: | White, round, scored, biconvex tablet. Debossed with 555/872 on the scored side and stylized b on the other side. | |
Available in bottles of: | ||
30 | NDC 0555-0872-01 | |
100 | NDC 0555-0872-02 | |
500 | NDC 0555-0872-04 | |
1000 | NDC 0555-0872-05 |
5 mg: | White, round, scored, biconvex tablet. Debossed with 555/873 on the scored side and stylized b on the other side. | |
Available in bottles of: | ||
30 | NDC 0555-0873-01 | |
100 | NDC 0555-0873-02 | |
500 | NDC 0555-0873-04 | |
1000 | NDC 0555-0873-05 |
10 mg: | White, round, scored, biconvex tablet. Debossed with 555/779 on the scored side and stylized b on the other side. | |
Available in bottles of: | ||
30 | NDC 0555-0779-01 | |
100 | NDC 0555-0779-02 | |
500 | NDC 0555-0779-04 | |
1000 | NDC 0555-0779-05 |
Dispense with a child-resistant closure in a tight container as defined in the USP.
Store at controlled room temperature 15°-30°C (59°-86°F) [see USP].
The text of the patient insert for progesterone and progesterone-like drugs is set forth below:
Medroxyprogesterone acetate tablets contain medroxyprogesterone acetate, a progesterone. The information below is that which the U.S. Food and Drug Administration requires be provided for all patients taking progesterones. The information below relates only to the risk to the unborn child associated with use of progesterone during pregnancy. For further information on the use, side effects and other risks associated with this product, ask your doctor.
Progesterone or progesterone-like drugs have been used to prevent miscarriage in the first few months of pregnancy. No adequate evidence is available to show that they are effective for this purpose. Furthermore, most cases of early miscarriage are due to causes which could not be helped by these drugs.
There is an increased risk of minor birth defects in children whose mothers take this drug during the first 4 months of pregnancy. Several reports suggest an association between mothers who take these drugs in the first trimester of pregnancy and genital abnormalities in male and female babies. The risk to the male baby is the possibility of being born with a condition in which the opening of the penis is on the underside rather than the tip of the penis (hypospadias). Hypospadias occurs in about 5 to 8 per 1,000 male births and is about doubled with exposure to these drugs. There is not enough information to quantify the risk to exposed female fetuses, but enlargement of the clitoris and fusion of the labia may occur, although rarely.
Therefore, since drugs of this type may induce mild masculinization of the external genitalia of the female fetus, as well as hypospadias in the male fetus, it is wise to avoid using the drug during the first trimester of pregnancy.
These drugs have been used as a test for pregnancy but such use is no longer considered safe because of possible damage to a developing baby. Also, more rapid methods for testing for pregnancy are now available.
If you take medroxyprogesterone acetate and later find you were pregnant when you took it, be sure to discuss this with your doctor as soon as possible.
MANUFACTURED BY
BARR LABORATORIES, INC.
POMONA, NY 10970
AUGUST 2001
BR-872, 873, 779
Medroxyprogesterone Acetate (Medroxyprogesterone Acetate) | ||||||||||||||||||||||||||||
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