HPC

• Approved Indications
• Prevention of Preterm Birth:
• Indicated for women with a singleton pregnancy and a history of spontaneous preterm birth to reduce the risk of recurrent preterm delivery.
• Hormone Replacement / Support:
• Used in select cases for progesterone deficiency during the second and third trimesters of pregnancy.
• Off-label / Clinically Accepted Uses
• Occasionally used for menstrual disorders such as secondary amenorrhea or abnormal uterine bleeding
• Management of endometriosis-related pain (limited clinical acceptance)
• Support in assisted reproductive technology cycles (ART) for luteal phase support

• Adults / Pregnant Women
• Typical Dose: 250 mg intramuscularly once weekly
• Initiation: Begin between 16–20 weeks of gestation
• Duration: Continue up to 37 weeks gestation or until delivery, whichever occurs first
• Elderly / Non-pregnant: Not typically used
• Pediatrics: Safety and efficacy not established
• Special Populations
• Renal / Hepatic Impairment: No specific dose adjustment, but use cautiously
• Administration Route
• Intramuscular injection only; avoid intravenous or subcutaneous use

Hydroxyprogesterone caproate is a synthetic progestogen that mimics the action of natural progesterone. It binds to progesterone receptors in uterine and cervical tissues, maintaining uterine quiescence by reducing myometrial contractions and modulating cervical remodeling. Additionally, it alters local prostaglandin and cytokine activity, decreasing the risk of premature labor and supporting the maintenance of pregnancy.

• Absorption: Slowly absorbed after intramuscular injection, providing sustained plasma levels
• Distribution: Highly protein-bound in plasma, primarily to albumin
• Metabolism: Metabolized in the liver via CYP3A4 enzymes
• Excretion: Metabolites eliminated primarily in urine and feces
• Onset: Therapeutic levels achieved within 24–48 hours post-injection
• Half-life: Approximately 7–9 days, allowing weekly dosing
• Active Metabolites: None clinically significant

• Pregnancy: Category B (no evidence of fetal harm in animal studies; limited human data). Specifically indicated for prevention of preterm birth in high-risk pregnancies.
• Lactation: Limited data; small amounts may be excreted in breast milk. Caution advised if breastfeeding, particularly in the early postpartum period.

• Primary Class: Progestogen / Progesterone analog
• Subclass: Injectable synthetic progestin

• Known hypersensitivity to hydroxyprogesterone caproate or any formulation components
• History of thromboembolic disorders (e.g., DVT, PE, stroke)
• Liver dysfunction or hepatic tumors
• Unexplained vaginal bleeding outside pregnancy
• Breast cancer or other progesterone-sensitive malignancies

• High-risk patient groups: Women with cardiovascular disease, diabetes, or thrombotic risk
• Potential serious risks:
• Thromboembolic events (rare but serious)
• Allergic reactions at injection site or systemically
• Monitoring:
• Periodic evaluation for blood pressure, liver function, and injection site reactions
• Early warning signs: Sudden shortness of breath, chest pain, leg swelling, jaundice, or severe injection site reactions

• Common: Injection site pain, headache, fatigue, mild edema, nausea
• Endocrine / Gynecologic: Irregular uterine bleeding, breast tenderness
• Serious / Rare:
• Thromboembolic events (DVT, PE, stroke)
• Allergic reactions including rash or urticaria
• Timing: Usually within days of injection; dose-dependent effects are rare due to weekly dosing

• CYP3A4 Inducers: (e.g., rifampin, phenytoin) may reduce therapeutic efficacy
• CYP3A4 Inhibitors: (e.g., ketoconazole, erythromycin) may increase plasma levels, enhancing risk of side effects
• Anticoagulants: May alter coagulation profiles; monitor carefully
• No significant food or alcohol interactions reported

• Guideline updates:
• ACOG recommends weekly 250 mg IM hydroxyprogesterone caproate for women with prior spontaneous preterm birth
• Avoid use in multiple gestations (twins/triplets) due to lack of efficacy
• Safety warnings: Emphasis on thromboembolic risk monitoring and caution in women with cardiovascular risk factors

• Store at 20°C to 25°C (room temperature)
• Protect from light and freezing
• Do not shake vigorously; maintain vial integrity
• Keep out of reach of children
• Single-use vials recommended; discard unused portion after administration