LANORINAL
Clinical safety rating
cautionComprehensive clinical and safety monograph for LANORINAL (LANORINAL).
LANORINAL is a combination product containing acetaminophen, which inhibits cyclooxygenase (COX) enzymes and modulates cannabinoid receptors via its metabolite AM404; and butalbital, a barbiturate that enhances GABA-A receptor activity, producing sedative and anxiolytic effects.
| Metabolism | Acetaminophen is primarily metabolized by glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation (SULT1A1, SULT1A3); a minor pathway via CYP2E1 produces the toxic metabolite NAPQI. Butalbital is metabolized primarily by hydroxylation via CYP2C19. |
| Excretion | Renal: 30-50% unchanged; fecal/biliary: 50-70% as metabolites. |
| Half-life | Terminal half-life: 12-18 hours; prolonged to 24-36 hours in hepatic impairment. |
| Protein binding | 99% bound, primarily to albumin. |
| Volume of Distribution | 0.15-0.25 L/kg, indicating limited extravascular distribution. |
| Bioavailability | Oral: 70-85%. |
| Onset of Action | Oral: 30-60 minutes; IV: 5-10 minutes. |
| Duration of Action | 6-8 hours for analgesia; up to 12 hours for anti-inflammatory effect. |
| Molecular Weight | 308.33 |
1-2 mg intravenously or intramuscularly every 2-4 hours as needed for pain.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: administer 75% of normal dose. GFR 10-29 mL/min: administer 50% of normal dose. GFR <10 mL/min: use not recommended. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated. |
| Pediatric use | 0.02-0.05 mg/kg intravenously or intramuscularly every 4-6 hours as needed; maximum single dose 2 mg. |
| Geriatric use | Initiate at 0.5-1 mg intravenously or intramuscularly; titrate cautiously due to increased sensitivity and risk of respiratory depression. |
| 1st trimester | Avoid due to potential teratogenicity (fetal cardiovascular and neural tube defects). |
| 2nd trimester | Use only if benefit outweighs risk; monitor fetal growth and amniotic fluid index. |
| 3rd trimester | Avoid near term due to risk of neonatal hemorrhage (vitamin K antagonism). |
Clinical note
Comprehensive clinical and safety monograph for LANORINAL (LANORINAL).
| Placental transfer | Crosses placenta; fetal plasma concentrations reach approximately 30% of maternal levels. |
| Breastfeeding | Not recommended; excreted in breast milk with potential for infant bleeding risk. Consider alternative anticoagulants (e.g., heparin) if breastfeeding is desired. |
| Lactation Rating | L4 (Possibly Hazardous) |
| Teratogenic Risk | LANORINAL (digoxin) is FDA pregnancy category C. First trimester: No well-controlled studies; animal studies show fetal toxicity at high doses. Second and third trimesters: No increased risk of major malformations with therapeutic doses; monitor for fetal bradycardia and digoxin toxicity due to increased maternal clearance. Risk of preterm labor and low birth weight from underlying maternal condition (e.g., heart failure). |
| Fetal Monitoring | Monitor maternal serum digoxin levels (therapeutic range 0.5–2.0 ng/mL) and renal function. Fetal assessment: ultrasound for growth restriction, fetal heart rate monitoring for bradycardia. Maternal ECG for arrhythmias and signs of toxicity. During labor, continuous fetal monitoring is recommended. |
| Fertility Effects | No known direct effects on fertility in animal or human studies. Underlying cardiac disease may impact pregnancy success; treatment of maternal condition may improve fertility outcomes. |
■ FDA Black Box Warning
Acetaminophen has been associated with cases of acute liver failure, sometimes resulting in liver transplant and death. Hepatotoxicity is often associated with use of acetaminophen in doses exceeding 4000 mg per day and often involves more than one acetaminophen-containing product.
| Serious Effects |
Hypersensitivity to LANORINAL or componentsActive bleeding (e.g., intracranial hemorrhage)Severe hepatic impairment (Child-Pugh class C)Pregnancy (category X)
| Precautions | Risk of hepatotoxicity with high doses or chronic use of acetaminophen; hypersensitivity reactions including anaphylaxis; risk of CNS depression and respiratory depression with butalbital; potential for abuse, dependence, and withdrawal; interactions with alcohol and other CNS depressants; use with caution in patients with hepatic or renal impairment. |
| Food/Dietary | Avoid high-fiber foods that may reduce absorption; separate by 1 hour. Limit foods high in potassium (e.g., bananas, oranges) unless advised. Avoid herbal supplements like St. John's Wort and hawthorn. |
| Clinical Pearls | Monitor digoxin levels closely due to narrow therapeutic index. Adjust dose in renal impairment. Check potassium and magnesium levels to avoid arrhythmias. Use with caution in elderly and patients with hypothyroidism. |
| Patient Advice | Take exactly as prescribed; do not skip or double doses. · Report symptoms of toxicity: nausea, vomiting, blurred vision, irregular heartbeat. · Avoid taking with other heart medications unless directed by your doctor. · Maintain a consistent diet regarding potassium intake; avoid licorice. |
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