Hydroxyprogesterone Caproate Injection

Dosage form: injection
Drug class:Progestins

Medically reviewed by Drugs.com. Last updated on May 1, 2021.

Hydroxyprogesterone Caproate Injection Description

Hydroxyprogesterone Caproate Injection, USP is a sterile, long-acting preparation of the caproate ester of the naturally- occurring progestational hormone, hydroxyprogesterone, in an oil solution for intramuscular use.

The chemical name for hydroxyprogesterone caproate is pregn-4-ene-3,20-dione, 17[(1-oxohexyl)oxy]. It has a molecular formula of C27H40O4 and a molecular weight of 428.60. Hydroxyprogesterone caproate exists as white or creamy white crystalline powder.

The structural formula is:


Each 5 mL multiple-dose vial contains hydroxyprogesterone caproate, 250 mg/mL, in castor oil (28.6% v/v) and benzyl benzoate (46 % v/v) with the preservative benzyl alcohol (2% v/v).

Hydroxyprogesterone Caproate Injection - Clinical Pharmacology

Hydroxyprogesterone is a potent, long-acting, progestational steroid ester which transforms proliferative endothelium into secretory endothelium, induces mammary gland duct development, and inhibits the production and/or release of gonadotropic hormone; it also shows slight estrogenic, androgenic, or corticoid effects as well, but should not be relied upon for these effects.

In advanced adenocarcinoma of the uterine corpus, Hydroxyprogesterone Caproate Injection, USP in a dosage of 1,000 mg or more, one or more times each week, often induces regressive changes.

Absorption: Peak serum levels of hydroxyprogesterone caproate appeared after 3 to 7 days in non-pregnant female subjects following a single intramuscular injection of 1,000 mg hydroxyprogesterone caproate. The pharmacokinetics of the 250 mg dose of hydroxyprogesterone caproate has not been evaluated in a study.

Metabolism: The conjugated metabolites include sulfated and glucuronidated products. In vitro data indicate that the metabolism of hydroxyprogesterone caproate is predominantly mediated by CYP3A4 and CYP3A5.

Excretion: Both conjugated metabolites and free steroids are excreted in the urine and feces, with the conjugated metabolites being prominent.