LERITINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LERITINE (LERITINE).
LERITINE (anileridine) is a synthetic opioid analgesic that acts as a mu-opioid receptor agonist, modulating pain perception and emotional response to pain.
| Metabolism | Hepatic metabolism via N-dealkylation and glucuronidation; CYP450 enzymes (likely CYP3A4) involved. |
| Excretion | Renal (70-90% as unchanged drug and metabolites); biliary/fecal (10-30%) |
| Half-life | 2-3 hours (terminal half-life in adults; may be prolonged in hepatic impairment or elderly, dosing adjustments recommended) |
| Protein binding | 85-95% bound primarily to alpha-1-acid glycoprotein and albumin |
| Volume of Distribution | 3-5 L/kg (extensive tissue distribution; high affinity for CNS and adipose tissue) |
| Bioavailability | Oral: 40-60% (first-pass metabolism); Intramuscular: 70-80% |
| Onset of Action | Intravenous: 1-2 minutes; Intramuscular: 10-15 minutes; Oral: 30-60 minutes |
| Duration of Action | Analgesic effect: 3-4 hours (IV/IM); 4-6 hours (oral) due to sustained release formulation |
Adults: 25-50 mg orally every 6 hours as needed for pain; not to exceed 200 mg/day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: reduce dose by 25%; GFR 15-29 mL/min: reduce dose by 50% and administer every 8-12 hours; GFR <15 mL/min: avoid use. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50% and administer every 8-12 hours; Child-Pugh Class C: avoid use. |
| Pediatric use | Weight-based: 0.5-1 mg/kg/dose orally every 6 hours as needed; maximum 4 mg/kg/day. |
| Geriatric use | Age >65 years: start at lower end of dosing range (12.5-25 mg orally every 6 hours), monitor for CNS and respiratory depression. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LERITINE (LERITINE).
| Breastfeeding | Excreted into breast milk; relative infant dose >10%, risk of neonatal sedation and respiratory depression. M/P ratio unknown; avoid breastfeeding while on leritine. Consider alternative agents. |
| Teratogenic Risk | Pregnancy category D. First trimester: Increased risk of congenital malformations, particularly neural tube defects and cardiac anomalies; avoid if possible. Second and third trimesters: Risk of fetal dependence and withdrawal syndrome, decreased fetal breathing movements, and neonatal respiratory depression at delivery; prolonged use may cause neonatal opioid withdrawal syndrome. |
■ FDA Black Box Warning
Risk of respiratory depression, addiction, abuse, misuse, and neonatal opioid withdrawal syndrome with prolonged use during pregnancy.
| Serious Effects |
Hypersensitivity to anileridine, significant respiratory depression, acute/suspected ileus, concurrent MAOI use or within 14 days.
| Precautions | Respiratory depression, CNS depression, hypotension, biliary tract spasm, seizure threshold reduction, serotonin syndrome risk with MAOIs, tolerance/dependence, withdrawal, impaired mental/physical abilities. |
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| Fetal Monitoring | Maternal: Respiratory rate, sedation level, bowel function, signs of tolerance or dependence. Fetal/neonatal: Heart rate variability, growth scans if chronic use, assessment for neonatal opioid withdrawal syndrome after delivery. |
| Fertility Effects | May alter gonadotropin secretion, potentially causing estrogen deficiency, anovulation, and impaired fertility. Reversible upon discontinuation. |