Pharmacokinetics of Subcutaneous Depot Medroxyprogesterone Acetate Injected in the Upper Arm

Background: The abdomen and thigh are recommended injection sites in the label for Depo-SubQ Provera 104™. We evaluated the pharmacokinetic profile of medroxyprogesterone acetate (MPA) following injection of Depo-SubQ Provera 104 in the upper arm, a preferred injection site in developing countries.

Study Design: Twenty-six women in Norfolk, VA, received a single injection of Depo-SubQ Provera 104 in the upper arm in this prospective noncomparative study. We measured MPA serum concentrations prior to injection (day 1) and 11 times postinjection (days 2, 4, 8, 14, 30, 44, 60, 74, 91, 104 and 120).

Results: Serum MPA levels peaked at 0.953 ng/mL 2-14 days (interquartile range; median=8) after dosing. Mean AUC0-91 was 45.1 ng·day/mL. Mean MPA levels at days 91, 104 and 120 were 0.427, 0.367 and 0.327 ng/mL, respectively. A total of 15 individual measurements of MPA were below 0.2 ng/mL. All women but one had MPA levels above 0.1 ng/mL on day 91.

Conclusions: Injection of Depo-SubQ Provera 104™ in the upper arm provided sufficient MPA levels for contraceptive protection for 3 months (13 weeks). The uptake and metabolism of MPA when injected in the upper arm may be different from the abdomen and thigh.