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.

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.

Hydroxyprogesterone Caproate Injection, USP is indicated in non-pregnant women: for the treatment of advanced adenocarcinoma of the uterine corpus (Stage III or IV); in the management of amenorrhea (primary and secondary) and abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as submucous fibroids or uterine cancer; as a test for endogenous estrogen production and for the production of secretory endometrium and desquamation.

Hydroxyprogesterone caproate is contraindicated in patients with known or suspected carcinoma of the breast, other hormone-sensitive cancer, or history of these conditions; undiagnosed abnormal vaginal bleeding; liver dysfunction or disease; missed abortion, and in those with a history of hypersensitivity to the drug. Hydroxyprogesterone caproate is also contraindicated as a diagnostic test for pregnancy and in patients with current or history of thrombotic or thromboembolic disorders.

Detectable amounts of progestins have been identified in the milk of mothers receiving the drug. Many studies have found no adverse effects of progestins on breastfeeding performance, or on the health, growth, or development of the infant.

A. Serious arterial thrombotic and venous thromboembolic events, including cases of pulmonary emboli (some fatal), deep vein thrombosis, myocardial infarction, and strokes, have been reported in women using progestins.

B. neuroocular lesions (e.g., retinal thrombosis and optic neuritis); nausea; vomiting; gastrointestinal symptoms (such as abdominal cramps or bloating); edema; breakthrough bleeding, spotting, or withdrawal bleeding; breast tenderness; changes in body weight (increase or decrease); headache; increase in cervical mucus; allergic rash; abscess; pain at the injection site; migraine headaches.

C. chloasma or melasma, cholestatic jaundice, rise in blood pressure, mental depression, and amenorrhea during or after treatment.

D. posttreatment anovulation, cystitis, hirsutism, loss of scalp hair, changes in libido, changes in appetite, dizziness, fatigue, backache, itching, or amenorrhea.

E. The following laboratory tests may be affected by progestins: hepatic function (increased sulfobromophthalein retention and other tests); coagulation tests (increased in prothrombin and Factors VII, VIII, IX, and X); thyroid function tests (increase in PBI and butanol extractable protein-bound iodine, decrease in T3 uptake values.

A few instances of coughing, dyspnea, constriction of the chest, and/or allergic-like reactions have occurred following hydroxyprogesterone caproate therapy; the likelihood of these occurring may be increased at higher dosage levels.

Suggested dosages are presented in the therapy guide. Because of the low viscosity of the vehicle, Hydroxyprogesterone Caproate Injection, USP may be administered with a small gauge needle. Care should be taken to inject the preparation deeply into the upper outer quadrant of the gluteal muscle following the usual precautions for intramuscular injection. Since the 250 mg potency provides a high concentration in a small volume, particular care should be observed to administer the full dose.

Hydroxyprogesterone Caproate Injection, USP is available in vials providing hydroxyprogesterone caproate with a potency of 250 mg per mL. The product is formulated in castor oil and 46% benzyl benzoate and containing 2% (v/v) benzyl alcohol as a preservative.