DELALUTIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DELALUTIN (DELALUTIN).
Progestogen; suppresses gonadotropin secretion, induces secretory endometrium, inhibits uterine contractions.
| Metabolism | Hepatic via CYP3A4 reduction and conjugation. |
| Excretion | Primarily renal; conjugated metabolites excreted in urine (50-60%) and bile/feces (30-40%). |
| Half-life | Terminal elimination half-life approximately 5.5 days (range 3-7 days), supporting weekly intramuscular dosing for sustained progestational effect. |
| Protein binding | 96-99% bound to albumin and corticosteroid-binding globulin (CBG). |
| Volume of Distribution | 0.5-1.0 L/kg, indicating extensive distribution into tissues, including adipose and reproductive organs. |
| Bioavailability | Intramuscular: near 100% due to route; oral: negligible (<5%) due to extensive first-pass metabolism; not available orally. |
| Onset of Action | Intramuscular: clinical effect on endometrium within 1-2 days; peak plasma concentration at 1-3 days. |
| Duration of Action | Intramuscular: progestational effect persists for 2-4 weeks; used for luteal phase support or contraception with injections every 7-14 days. |
Hydroxyprogesterone caproate: 250-500 mg IM weekly, starting at 16-20 weeks gestation and continuing until 37 weeks or delivery, for prevention of preterm birth in women with singleton pregnancy and prior spontaneous preterm birth.
| Dosage form | SOLUTION |
| Renal impairment | No specific dose adjustment guidelines available. Use with caution in severe renal impairment due to potential accumulation; monitor for adverse effects. |
| Liver impairment | Contraindicated in severe hepatic dysfunction (Child-Pugh class C). For mild to moderate (Child-Pugh A or B), use with caution and monitor liver function; consider dose reduction or alternative therapy due to risk of reduced clearance. |
| Pediatric use | Safety and efficacy not established in pediatric patients; use is not indicated for preterm birth prevention in adolescents due to lack of data. |
| Geriatric use | Not indicated for use in geriatric patients; no specific dosing guidelines available. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DELALUTIN (DELALUTIN).
| Breastfeeding | Delalutin is excreted in breast milk in small amounts. M/P ratio not explicitly reported. No known adverse effects on infant from maternal use; however, theoretical risk of hormonal effects. Consider alternative contraception if breastfeeding. |
| Teratogenic Risk | Delalutin (hydroxyprogesterone caproate) is a progestin. First trimester: Risk of hypospadias and congenital heart defects based on some studies; however, definitive causal link not established. Second/third trimester: No increased risk of major malformations; used for preterm birth prevention. Overall, FDA Pregnancy Category B. |
■ FDA Black Box Warning
None.
| Serious Effects |
Known or suspected pregnancy, undiagnosed vaginal bleeding, known or suspected breast cancer (unless for treatment), active thromboembolic disease, liver disease or dysfunction, hypersensitivity to hydroxyprogesterone caproate.
| Precautions | Thromboembolic disorders, myocardial infarction, stroke, hepatic impairment, breast cancer risk, fluid retention, depression, carbohydrate intolerance, ocular disorders. |
| Food/Dietary | No specific food interactions are reported. Grapefruit juice may inhibit CYP3A4 metabolism, but clinical significance is unclear; advise avoidance of excessive grapefruit consumption. |
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| Fetal Monitoring | Monitor maternal blood pressure, glucose levels, and signs of thromboembolic disease. In pregnancy, monitor fetal growth and amniotic fluid index if used prolonged. No specific fetal monitoring required for short-term use. |
| Fertility Effects | Delalutin may suppress ovulation if used as contraceptive; no permanent negative effects on fertility. Reversible upon discontinuation. |
| Clinical Pearls |
| Hydroxyprogesterone caproate (Delalutin) is a synthetic progestin used to reduce the risk of preterm birth in women with a singleton pregnancy and a history of spontaneous preterm birth. Administer intramuscularly 250 mg weekly starting at 16-20 weeks gestation until 36 weeks or delivery. Monitor injection site for pain, swelling, or abscess. Contraindicated in women with current or history of thromboembolic disorders, known/suspected breast cancer, or liver dysfunction. Not effective for multiple gestations, cervical insufficiency, or preterm labor. May cause transient injection site reactions, pruritus, and urticaria. |
| Patient Advice | You will receive weekly injections of this medication into a muscle, usually the buttock, until week 36 of pregnancy or until your baby is delivered, whichever comes first. · Common side effects include injection site pain, swelling, or itching; hives; and nausea. Contact your healthcare provider if you have severe injection site reactions, signs of blood clots (leg swelling, chest pain, shortness of breath), or jaundice. · This medication does not prevent all preterm births and is not a treatment for active preterm labor or cervical insufficiency. · Do not use this medication if you have a history of blood clots, breast cancer, liver disease, or unexplained vaginal bleeding. · Inform your healthcare provider of all medications you are taking, as this drug may interact with certain anticonvulsants, rifampin, and protease inhibitors. |