LYBALVI
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LYBALVI (LYBALVI).
LYBALVI is a combination of olanzapine and samidorphan. Olanzapine is an atypical antipsychotic with high affinity for serotonin 5-HT2A and 5-HT2C, dopamine D1-D4, histamine H1, and alpha1-adrenergic receptors. Samidorphan is an opioid receptor antagonist with high affinity for mu-opioid receptors, hypothesized to reduce olanzapine-associated weight gain by blocking opioid receptors in the central nervous system.
| Metabolism | Olanzapine is extensively metabolized via direct glucuronidation and CYP1A2-mediated oxidation. Samidorphan is primarily metabolized by CYP3A4 and to a lesser extent by CYP2C8. |
| Excretion | Renal: ~50% as unchanged drug and metabolites; Fecal: ~40%; Biliary: minor. |
| Half-life | Terminal half-life ~20-30 hours; supports once-daily dosing. |
| Protein binding | ~99% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Approximately 10-15 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral: ~80% (tablet); not administered parenterally. |
| Onset of Action | Oral: 2-4 weeks for initial clinical response in schizophrenia; 1-2 weeks for bipolar depression. |
| Duration of Action | Sustained symptom control with chronic daily dosing; steady-state achieved in 5-7 days. |
| Molecular Weight | 469 |
Olanzapine 10 mg / samidorphan 10 mg orally once daily.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73 m²). Not recommended in severe renal impairment (eGFR <30 mL/min/1.73 m²) due to insufficient data. |
| Liver impairment | No dose adjustment required for mild hepatic impairment (Child-Pugh A). Not recommended in moderate to severe hepatic impairment (Child-Pugh B or C) due to insufficient data. |
| Pediatric use | Safety and effectiveness in pediatric patients have not been established. |
| Geriatric use | No specific dose adjustment recommended; use with caution due to increased sensitivity to olanzapine (e.g., orthostatic hypotension, sedation) and limited data in patients ≥65 years. |
| 1st trimester | Limited human data; avoid use in first trimester unless benefit outweighs risk. Has shown teratogenicity in animal studies. |
| 2nd trimester | Use only if clearly needed; potential for fetal adverse effects due to anticholinergic and antipsychotic mechanisms. |
| 3rd trimester | Risk of neonatal extrapyramidal symptoms and withdrawal; avoid use near term. |
Clinical note
Comprehensive clinical and safety monograph for LYBALVI (LYBALVI).
| Placental transfer | Crosses placenta; detected in fetal plasma and amniotic fluid in animal studies. |
| Breastfeeding | Excreted in breast milk in low concentrations. Monitor infant for sedation, irritability, and feeding difficulties. Consider alternative agents if available. |
| Lactation Rating |
■ FDA Black Box Warning
Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. LYBALVI is not approved for the treatment of patients with dementia-related psychosis.
| Serious Effects |
Hypersensitivity to olanzapine or samidorphan or any componentConcurrent use with opioid analgesics or opioid agonists (including partial agonists)Acute opioid intoxication or opioid withdrawalHistory of severe allergic reaction to similar agents
| Precautions | Increased mortality in elderly patients with dementia-related psychosis, Neuroleptic malignant syndrome (NMS), Tardive dyskinesia, Metabolic changes (hyperglycemia, dyslipidemia, weight gain), Orthostatic hypotension and syncope, Falls, Seizures, Leukopenia, neutropenia, and agranulocytosis, Dysphagia, Body temperature dysregulation, Anticholinergic effects, Potential for opioid withdrawal with samidorphan component, Hepatic impairment |
| Food/Dietary | Grapefruit and grapefruit juice may increase olanzapine concentrations and should be avoided. High-fat meals may delay absorption of olanzapine; take consistently with or without food. No specific dietary restrictions with samidorphan. Alcohol may enhance CNS depression and should be limited or avoided. |
Loading safety data…
| L4 (Possibly Hazardous) |
| Teratogenic Risk | LYBALVI (olanzapine/samidorphan) is classified as Pregnancy Category C. First-trimester exposure: No adequate human studies; animal studies with olanzapine showed fetal toxicity (reduced fetal weight, delayed ossification) at doses >2 times MRHD; samidorphan animal studies showed no teratogenicity at clinically relevant doses. Second and third trimesters: Olanzapine may cause extrapyramidal symptoms and/or withdrawal symptoms in neonates; risk of gestational diabetes, weight gain, and hypertension. Use only if benefit clearly outweighs risk. |
| Fetal Monitoring | Maternal: Blood glucose, weight, blood pressure, lipid profile, signs of EPS or metabolic syndrome. Fetal/Neonatal: Third-trimester exposure requires neonatal monitoring for extrapyramidal symptoms, withdrawal, sedation, respiratory distress. Consider ultrasound for fetal growth if prolonged use. |
| Fertility Effects | Olanzapine may cause hyperprolactinemia leading to menstrual irregularities, galactorrhea, and reduced fertility in females. Samidorphan has no known independent effects. In males, olanzapine may reduce libido and erectile function. Effects are reversible upon discontinuation. |
| Clinical Pearls | LYBALVI (olanzapine/samidorphan) combines olanzapine, an atypical antipsychotic, with samidorphan, an opioid receptor antagonist, to mitigate olanzapine-induced weight gain. Monitor for opioid withdrawal in opioid-dependent patients; samidorphan can precipitate acute withdrawal. Avoid use with other opioid antagonists or partial agonists (e.g., naltrexone, buprenorphine). Assess for metabolic syndrome, including weight, waist circumference, fasting glucose, and lipids at baseline and periodically. Use with caution in patients with history of seizures or with conditions that lower seizure threshold. Do not administer to patients receiving opioids or during opioid withdrawal; start LYBALVI only after opioid-free interval (e.g., 7-14 days for short-acting, longer for long-acting). Tablet is scored; dose adjustments needed for hepatic impairment. No direct QTc prolongation expected, but olanzapine may cause orthostatic hypotension; titrate slowly. |
| Patient Advice | Take LYBALVI exactly as prescribed; do not stop without consulting your doctor. · This medication combines two drugs: olanzapine treats psychosis, and samidorphan helps reduce weight gain from olanzapine. · Do not use LYBALVI if you are taking opioid pain relievers, opioid dependence medications, or have recently used opioids (e.g., codeine, morphine, heroin). It can cause severe opioid withdrawal. · Avoid alcohol and grapefruit juice while taking this medication as they may increase side effects or affect drug levels. · Monitor your weight weekly; report rapid or significant weight gain to your healthcare provider. · Be aware of drowsiness, dizziness, or lightheadedness, especially when starting; avoid driving or operating machinery until you know how the drug affects you. · Seek immediate medical attention if you experience symptoms of neuroleptic malignant syndrome (fever, muscle rigidity, confusion) or tardive dyskinesia (uncontrolled facial or limb movements). · Report new or worsening depression, suicidal thoughts, or mood changes. |