During pregnancy and the luteal phase of the menstrual cycle, women can hyperventilate and become hypocapnic due to elevated concentrations of endogenous progestins. Therapeutically, medroxyprogesterone has been used successfully in patients with COPD and hypercapnia, in patients with Pickwickian syndrome, and in patients with sleep apnea. Oral bioavailability is not known. Following a single IM dose, concentrations increase progressively for 3 weeks, then begin to decrease exponentially to undetectable levels at 120-200 days following the injection. The half-life following IM administration of the depot form is 50 days.
Metabolism is hepatic, and elimination is primarily fecal.
Medroxyprogesterone is absolutely contraindicated in patients with hepatic disease, hepatic dysfunction, incomplete abortion, suspected pregnancy, or abnormal and undiagnosed vaginal bleeding. The relative risk of developing breast cancer in patients receiving depot medroxyprogesterone for contraception has been investigated in a number of trials. The duration of use was not a factor, that is, the incidence with a single dose was the same as with multiple doses. Depot medroxyprogesterone may accelerate the growth of occult cancers, but is not necessarily a risk factor for breast cancer. D Medroxyprogesterone is contraindicated in patients with pre-existing breast carcinoma or carcinoma of reproductive organs, except for palliative therapy in selected patients.