In vivo metabolism of H3-medroxyprogesterone acetate in pregnant and nonpregnant women and in the fetus

Adrenal steroids as parameters of the bioavailability of MA and MPA

Serum levels of cortisol (C), androstenedione (A), dehydroepiandrosterone (D), estrone (E1) and estradiol (E2) were chosen as parameters to compare the bioavailability of megestrol acetate (MA) and medroxyprogesterone acetate (MPA) in postmenopausal patients with advanced breast cancer. In 36 patients randomized to MPA, the levels of A (13% vs. 19%) and C (6% vs. 8%) were slightly lower than in 36 patients on MA, but D-levels (68% vs. 59%) and E1 or E2, were similar. The correlation between baseline C and A disappeared during treatment. Treatment levels of E1 and E2 were correlated. There was no correlation between individual drug levels and any steroid, indicating a maximal suppression. After ingestion of a single dose of MA or MPA, peak levels were found after 2-3 h for MA and 3-4 h for MPA. Four hours after ingestion, the levels of A and C were similar, 40-60% of baseline values, while D levels remained unaltered. Doubling the dose of either drug did not enhance hormone suppression, indicating that the drug dosage is maximally suppressive. In conclusion, although the median serum MA levels are double those of MPA, suppression of A, C and D is usually similar, with corresponding estrogen levels, demonstrating a comparable and maximal bioavailability. Higher dosages of MA or MPA will not increase their pharmacological effects any further.

The effect of depot-medroxyprogesterone acetate on the fetus and nursing infant: a review

Data from published studies of the quantity of medroxyprogesterone acetate and/or its metabolites in the milk of lactating women receiving Depo-Provera for contraception is extrapolated into the amount of drug ingested daily by a theoretically average infant. Comparisons are made with the results of similar studies in animals. Fetal metabolism of medroxyprogesterone acetate is reviewed. Embryonic and fetal development of the human reproductive system is discussed. Results of studies of the effects of steroidal hormones, particularly medroxyprogesterone acetate, on mental development and sexual dimorphic behavior after exposure in utero are presented. It is concluded that the very small amount of drug and/or its metabolites ingested by the nursing infant via breast milk is highly unlikely to have any significant effect on the nursing infant.

Isolation and partial synthesis of a new metabolite of medroxyrogesterone acetate

3 alpha-Hydroxy-17-acetoxy-6 alpha-methyl-5 beta-pregnan-20-one (IIIa) has been isolated from urine of patients receiving medroxyprogesterone acetate (MPA). It was characterized by partial synthesis from MPA by catalytic reduction with palladium-charcoal to 17-acetoxy-6 alpha-methyl-5 beta-pregnan-3,20-dione (IV) and reduction of the latter with sodium borohydride. The isolation of 6 beta, 17,21-trihydroxy-6 alpha-methyl-pregn-4-ene-3,20-dione (IIc) is reported for the first time. The 17- and 21-monoacetates of this compound have been isolated and characterized earlier by other investigators. 7 alpha-3H-Medroxyprogesterone acetate was administered to 4 subjects by intravenous and intramuscular injections and by mouth. The ring A saturated metabolite IIIa was excreted in 0.1% to 4.0% of the administered dose; the highest excretion was after the intravenous dose and lowest after oral ingestion. 6 beta, 17,21-Trihydroxy-6 alpha-methylpregn-4-ene-3,20-dione (IIc) and its 17- and 21-monoacetates were excreted in about 5% of the doses in all subjects. No increase in 6 beta-hydroxylation was observed in the patient treated with o,p'-DDD,2,2-bis(2-chlorophenyl, 4'-chlorophenyl)-l,1-dichloroethane.