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. |
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 | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Causes an initial increase in testosterone levels which may worsen symptoms in prostate cancer patients.
| FDA category | Contraindicated |
| Breastfeeding | Leuprolide acetate is not recommended during breastfeeding. No data on M/P ratio. Likely excreted in milk due to low molecular weight, but absorption is minimal due to peptide nature. Potential for adverse effects on infant hormonal development. |
| 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. |
■ 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 |
["Hypersensitivity to leuprolide or any component of the formulation","Pregnancy (can cause fetal harm)","Breastfeeding (some formulations)","Undiagnosed abnormal vaginal bleeding","Use in women with endometriosis for longer than 6 months (risk of bone loss)"]
| 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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| 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. |