hydroxyprogesterone caproate (DSC)

Drug Overview

In the clinical field of Gynecology and Obstetrics, hydroxyprogesterone caproate represents a significant pharmacological intervention within the Progestin Hormone drug class. This medication is a synthetic derivative of naturally occurring progesterone, designed as a long-acting Hormone Modulator to support the maintenance of pregnancy. Historically, it served as a primary systemic therapy for women with a specific history of spontaneous preterm birth, aiming to extend the gestational period and improve neonatal outcomes.Discover detailed information on hydroxyprogesterone caproate (DSC). As a Progestin Hormone, it is prescribed for Reduction of preterm birth risk. Contact us.

It is important to note that as of 2023, the FDA and international regulatory bodies initiated a Discontinued (DSC) status for the branded version of this drug in the US market following comprehensive efficacy reviews. However, it remains a subject of significant clinical discussion regarding hormonal support in pregnancy and is still utilized in various international markets under strict specialist supervision.

• Generic Name: Hydroxyprogesterone caproate
• US Brand Names: Makena (DSC), Delalutin (DSC)
• Drug Class: Progestin; Hormone Modulator
• Route of Administration: Intramuscular (IM) injection or Subcutaneous (SC) auto-injector
• FDA Approval Status: Discontinued (DSC); previously approved under the accelerated approval pathway for the reduction of the risk of preterm birth.

What Is It and How Does It Work? (Mechanism of Action)

Hydroxyprogesterone caproate functions as a potent Hormone Modulator by interacting with the body’s internal progesterone signaling pathways. During pregnancy, progesterone is often called the “hormone of pregnancy” because it is essential for keeping the uterus in a relaxed, non-contractile state.

Molecular and Cellular Interaction

The drug works at a molecular level to prevent the early onset of labor through several complex mechanisms:

1. Hormone Receptor Agonism: Hydroxyprogesterone caproate binds to and activates progesterone receptors located in the myometrium (the muscular layer of the uterus). This activation leads to the transcription of genes that promote “uterine quiescence,” effectively keeping the muscle relaxed.
2. Anti-Inflammatory Modulation: Preterm labor is often triggered by an inflammatory cascade. This progestin acts as an Immunotherapy of sorts by inhibiting the production of pro-inflammatory cytokines and prostaglandins. By suppressing these molecular signals, the drug helps prevent the premature ripening of the cervix and the initiation of uterine contractions.
3. Progesterone Blockade Theory: It is hypothesized that the drug helps maintain a “progesterone block” over the uterus, counteracting the effects of oxytocin and other hormones that normally trigger labor at full term.
4. Cervical Integrity: By modulating the connective tissue of the cervix, the drug helps maintain cervical length and strength, preventing early shortening which is a primary precursor to preterm delivery.

FDA-Approved Clinical Indications

Primary Gynecological/Obstetric Indications

• Reduction of Preterm Birth Risk: Specifically indicated for women with a singleton pregnancy who have a documented history of at least one spontaneous preterm birth (defined as delivery before 37 weeks of gestation).

Off-Label / Endocrinological Indications

• Management of Amenorrhea: Used historically to induce withdrawal bleeding in non-pregnant women with primary or secondary amenorrhea.
• Abnormal Uterine Bleeding: Treatment of uterine bleeding due to hormonal imbalance in the absence of organic pathology.
• Endometrial Cancer Support: Utilized as a palliative Targeted Therapy for advanced or recurrent endometrial carcinoma (Stage III or IV).
• Luteal Phase Support: Occasionally used in assisted reproductive technology (ART) protocols to support the early stages of embryo implantation.

Dosage and Administration Protocols

The administration of hydroxyprogesterone caproate follows a strict weekly schedule to ensure stable plasma concentrations of the Hormone Modulator.

Specific Population Considerations

• Renal Insufficiency: No specific dose adjustments are typically required as the drug is primarily metabolized by the liver.
• Hepatic Insufficiency: Contraindicated in patients with active liver disease or severely impaired liver function, as the caproate ester requires hepatic clearance.
• Allergy Warning: Formulations often contain castor oil or sesame oil; patients with known sensitivities to these oils must avoid the medication.

Clinical Efficacy and Research Results

The clinical history of hydroxyprogesterone caproate is marked by two major trials that shaped its regulatory standing between 2020 and 2026.

• The Meis Trial Data: Initial research showed that the drug reduced the rate of preterm birth (before 37 weeks) to 36.3 percent, compared to 54.9 percent in the placebo group, representing a nearly 34 percent reduction in risk.
• The PROLONG Trial (2020): This follow-up confirmatory trial involved over 1,700 participants. The results showed that the rate of preterm birth before 35 weeks was 11 percent in the treated group versus 11.5 percent in the placebo group. This lack of statistically significant difference led to the eventual recommendation for withdrawal from the market.
• Gestational Extension: While primary efficacy was questioned in general populations, subsets of specialist data (2022-2024) suggested that in extremely high-risk patients, the drug might contribute to an average extension of pregnancy by 1.5 to 2.1 weeks.
• Neonatal Outcomes: Research parameters during the PROLONG study found no significant difference in the incidence of neonatal respiratory distress syndrome or intraventricular hemorrhage between the treated and untreated groups.

Safety Profile and Side Effects

Black Box Warning

There is no “Black Box Warning” for hydroxyprogesterone caproate; however, it carries a strict contraindication for women with current or past thrombosis (blood clots) or known or suspected breast cancer.

Common Side Effects (>10%)

• Injection Site Reactions: Pain, swelling, itching, or the formation of a small nodule at the site of injection.
• Urticaria: Hives or localized skin rashes.
• Nausea: Mild gastrointestinal discomfort following administration.

Serious Adverse Events

• Thromboembolic Disorders: Increased risk of pulmonary embolism or deep vein thrombosis (VTE).
• Glucose Intolerance: Potential for decreased insulin sensitivity, requiring monitoring for gestational diabetes.
• Depression: New-onset or worsening of clinical depression in predisposed patients.
• Fluid Retention: Significant swelling (edema) in patients with pre-existing renal or cardiac conditions.

Management Strategies

Injection site nodules are typically managed with warm compresses and rotation of the injection site. If gestational diabetes develops, standard nutritional counseling and insulin therapy are initiated. If signs of depression occur, the Hormone Modulator may need to be discontinued in favor of alternative maternal health support.

Research Areas

In the landscape of modern Gynecology, hydroxyprogesterone caproate is moving into new Research Areas focused on Targeted Therapy and advanced delivery. Current clinical trials (2025) are investigating biodegradable implants that could provide a steady release of the progestin without the need for weekly painful injections.

Regarding Regenerative Medicine, there is emerging interest in how progestins influence the “molecular environment” of the cervix. Researchers are looking at whether combining hormonal therapy with Stem Cell-derived growth factors can help repair a “weak” or “incompetent” cervix by stimulating collagen production and tissue repair. While still in the experimental phase, this intersection of Hormone Modulator therapy and regenerative technology aims to address the root causes of preterm birth rather than just the symptoms.

Patient Management and Practical Recommendations

Pre-treatment Tests

• Pelvic Ultrasound: To confirm a singleton pregnancy and establish accurate gestational age.
• Medical History Review: Detailed documentation of previous spontaneous preterm births.
• Baseline Glucose: To assess for pre-existing diabetes or insulin resistance.
• Liver Function Tests: To ensure the patient can safely metabolize the progestin ester.

Precautions During Treatment

• Symptom Vigilance: Patients must be educated on the signs of preterm labor (contractions, pelvic pressure, or fluid leakage) and must not assume the medication makes them “immune” to these events.
• Blood Pressure Monitoring: Regular checks during weekly clinic visits.
• VTE Awareness: Monitoring for sudden leg swelling or shortness of breath.

Do’s and Don’ts

• DO keep your injection appointments exactly 7 days apart to maintain effective hormone levels.
• DO rotate the injection site between the left and right sides each week.
• DON’T use this medication if you are pregnant with multiples (twins or triplets), as research indicates it is not effective and may increase risks in these cases.
• DON’T stop the medication early without a direct order from your Obstetrician, as this can trigger a sudden hormonal drop.

Legal Disclaimer

This guide is for informational purposes only and does not replace professional medical advice from a qualified healthcare provider. Hydroxyprogesterone caproate is a prescription Hormone Modulator that has been discontinued in several markets due to efficacy concerns; its use should only be considered under the guidance of a Maternal-Fetal Medicine specialist. If you experience signs of early labor or a allergic reaction, seek emergency medical attention immediately.