LEUPROLIDE ACETATE FOR DEPOT SUSPENSION
Clinical safety rating: avoid
No significant drug interactions Causes an initial increase in testosterone levels which may worsen symptoms in prostate cancer patients.
Leuprolide acetate is a synthetic gonadotropin-releasing hormone (GnRH) agonist. Continuous administration suppresses pituitary gonadotropin secretion, leading to decreased luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thereby reducing gonadal steroid production (testosterone and estrogen).
| Metabolism | Leuprolide is primarily degraded by peptidases and proteolytic enzymes in tissues and plasma. It is not significantly metabolized by cytochrome P450 enzymes. Hepatic metabolism is minor. |
| Excretion | Primarily renal (metabolites), approximately 5% unchanged; fecal elimination accounts for <5%. |
| Half-life | 3-4 hours for subcutaneous injection; after depot injection, initial burst release followed by slow release with apparent half-life of approximately 3-4 weeks due to absorption rate-limited elimination. |
| Protein binding | Approximately 46% bound to serum proteins (primarily albumin). |
| Volume of Distribution | Approximately 27-33 L (0.4 L/kg) after intravenous administration; not extensively distributed to tissues. |
| Bioavailability | Subcutaneous daily: 100%; Depot intramuscular: approximately 85% (due to incomplete release and/or presystemic degradation). |
| Onset of Action | Subcutaneous daily: 2-4 weeks to achieve castrate testosterone levels; Depot (1-month): 3-4 weeks; Depot (3-month): 4-8 weeks. |
| Duration of Action | Depot (1-month): maintains castrate testosterone levels for 1 month; Depot (3-month): for 3 months; continuous daily dosing maintains suppression. |
| Molecular Weight | 1269.47 Da |
3.75 mg IM every 4 weeks or 11.25 mg IM every 12 weeks for advanced prostate cancer; 3.75 mg IM every month for endometriosis or uterine leiomyomas; 7.5 mg IM monthly for central precocious puberty.
| Dosage form | FOR SUSPENSION |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (GFR <30 mL/min), use with caution; no specific dose adjustment established. |
| Liver impairment | No dose adjustment recommended for Child-Pugh A or B. For Child-Pugh C, use with caution; no specific dose adjustment established. |
| Pediatric use | Central precocious puberty: 0.3 mg/kg IM every 28 days (minimum dose 7.5 mg); or 11.25 mg IM every 12 weeks for children weighing ≥25 kg. Adjust dose based on pubertal suppression. |
| Geriatric use | No specific age-related dose adjustment. Monitor for bone density loss, cardiovascular events, and glucose intolerance due to prolonged androgen deprivation. |
| 1st trimester | Leuprolide acetate is contraindicated in pregnancy. Potential for fetal harm based on mechanism of action (gonadotropin suppression). Risk of spontaneous abortion or fetal abnormalities. |
| 2nd trimester | Contraindicated in pregnancy. Continued gonadotropin suppression may impair placental function and fetal development. |
| 3rd trimester | Contraindicated in pregnancy. May interfere with parturition and cause fetal harm. |
Clinical note
No significant drug interactions Causes an initial increase in testosterone levels which may worsen symptoms in prostate cancer patients.
| FDA category | Contraindicated |
| Placental transfer | Leuprolide acetate is a synthetic peptide analog of GnRH. Low molecular weight but high polarity likely restricts placental transfer. However, based on animal studies showing fetal effects, some transfer may occur. |
■ FDA Black Box Warning
None explicitly required; however, Leuprolide can cause initial testosterone surge in prostate cancer patients, potentially leading to worsening of symptoms (e.g., bone pain, ureteral obstruction, spinal cord compression). This surge is not a formal black box warning but is a significant safety concern.
| Common Effects | Decreased libido Testicular atrophy Increased sweating Fatigue Muscle weakness Erectile dysfunction Bone pain Injection site reaction Hot flashes |
| Serious Effects |
PregnancyHypersensitivity to leuprolide acetate or any component of the formulationUndiagnosed abnormal vaginal bleeding (if using for endometriosis)
| Precautions | Initial transient increase in serum testosterone or estradiol may worsen prostate cancer symptoms (e.g., bone pain, ureteral obstruction) or cause transient worsening of endometriosis., Risk of hyperglycemia and diabetes mellitus in prostate cancer patients on androgen deprivation therapy (ADT)., Cardiovascular risks (myocardial infarction, sudden cardiac death) with long-term use., Decreased bone mineral density with prolonged use; consider calcium/vitamin D supplementation., Seizures reported, especially in patients with epilepsy or predisposing factors., QT prolongation risk, particularly in patients with electrolyte abnormalities or on QT-prolonging drugs. |
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| Breastfeeding | It is not known if leuprolide acetate is excreted in human milk. Due to potential for serious adverse reactions in nursing infants, decision should be made to discontinue nursing or discontinue drug, taking into account importance of drug to mother. |
| Lactation Rating | L5 (Contraindicated) |
| Teratogenic Risk | Leuprolide acetate is contraindicated in pregnancy. First trimester exposure is associated with an increased risk of spontaneous abortion and potential teratogenicity based on animal studies showing fetal resorption and malformations. No adequate human studies exist; theoretical risk of hormonal disruption to fetal development. |
| Fetal Monitoring | Monitor pregnancy status with serum hCG before initiating therapy. Document negative pregnancy test. During use, monitor for signs of pregnancy (e.g., missed menses, spotting). If pregnancy suspected, discontinue immediately and perform ultrasound for fetal assessment. |
| Fertility Effects | Leuprolide suppresses gonadotropin secretion, causing reversible inhibition of ovulation and spermatogenesis. In women, reduces ovarian estrogen production; in men, lowers testosterone. Fertility typically returns after discontinuation, but time to recovery varies. |
| Food/Dietary | No significant food interactions. No dietary restrictions required. Avoid grapefruit juice if also on certain CYP3A4 substrates (unlikely relevant for leuprolide, but check concomitant medications). Maintain adequate calcium and vitamin D intake to mitigate osteoporosis risk. |
| Clinical Pearls | Monitor for initial flare of symptoms (e.g., increased bone pain in prostate cancer) during first 2-4 weeks due to transient testosterone surge. Administer every 1, 3, 4, or 6 months depending on formulation. Do not crush or chew depot microspheres; ensure proper reconstitution and use of provided diluent. Screen for pregnancy before initiation and use contraception during therapy. Assess bone density in patients at risk for osteoporosis with prolonged use. |
| Patient Advice | This medication may cause a temporary increase in symptoms such as bone pain or urinary problems during the first few weeks of treatment. · You may experience hot flashes, decreased libido, or erectile dysfunction. These are expected effects of hormone suppression. · Do not stop taking this medication abruptly; consult your healthcare provider before discontinuing. · The depot suspension must be administered by a healthcare professional; it is not self-injectable. · Avoid pregnancy during treatment; use effective contraception for at least 2 weeks after the first injection. · Report any signs of allergic reaction (rash, hives, difficulty breathing) or injection site reactions (pain, swelling, abscess). · Long-term use may increase risk of bone thinning; ensure adequate calcium and vitamin D intake and discuss bone health with your doctor. |