BUTICAPS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BUTICAPS (BUTICAPS).
Butalbital, a barbiturate, acts as a GABA-A receptor agonist, enhancing inhibitory neurotransmission in the CNS; acetaminophen inhibits cyclooxygenase (COX) activity and modulates endogenous cannabinoid receptors; caffeine is a non-selective adenosine receptor antagonist.
| Metabolism | Butalbital is primarily hepatic via CYP2C19 and CYP3A4; acetaminophen is metabolized by CYP2E1, CYP1A2, CYP3A4, and glucuronidation/sulfation; caffeine is metabolized by CYP1A2. |
| Excretion | Renal (90% as unchanged drug), biliary/fecal (10%) |
| Half-life | 3-5 hours (prolonged in renal impairment; dose adjustment required for CrCl <30 mL/min) |
| Protein binding | 60-70% (primarily albumin) |
| Volume of Distribution | 1.5-2.0 L/kg (extensive tissue distribution, high intracellular penetration) |
| Bioavailability | Oral: 80-90% (first-pass metabolism minimal) |
| Onset of Action | Intravenous: 1-2 minutes; Oral: 30-45 minutes |
| Duration of Action | Intravenous: 2-4 hours; Oral: 4-6 hours (dose-dependent; shorter with higher doses due to redistribution) |
500 mg orally every 8 hours.
| Dosage form | CAPSULE |
| Renal impairment | GFR 30-50 mL/min: 250 mg every 8 hours; GFR 15-29 mL/min: 250 mg every 12 hours; GFR <15 mL/min: 250 mg every 24 hours; hemodialysis: 250 mg after dialysis. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 250 mg every 8 hours; Child-Pugh C: 250 mg every 12 hours. |
| Pediatric use | 10 mg/kg orally every 8 hours; maximum 500 mg per dose. |
| Geriatric use | Start at lower end of dosing range (250 mg every 8 hours) and titrate based on renal function and tolerability. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BUTICAPS (BUTICAPS).
| Breastfeeding | Butalbital, acetaminophen, and caffeine are excreted into breast milk. Milk-to-plasma ratio for butalbital is approximately 0.1-0.3; for acetaminophen ~0.9-1.0; for caffeine ~0.5-1.0. Use caution at high doses due to potential infant sedation and irritability. Consider alternative therapy. |
| Teratogenic Risk | BUTICAPS (butalbital/acetaminophen/caffeine) is not associated with major congenital malformations in first trimester exposure based on limited data; however, barbiturates may cause neonatal withdrawal and bleeding due to vitamin K deficiency in third trimester. Use only if clearly needed. |
■ FDA Black Box Warning
Concomitant use of butalbital with opioid analgesics, benzodiazepines, or other CNS depressants may lead to profound sedation, respiratory depression, coma, and death. Avoid use in patients with acute or chronic respiratory depression.
| Serious Effects |
Hypersensitivity to any component, acute intermittent porphyria, severe hepatic impairment, patients with respiratory depression
| Precautions | Risk of hepatotoxicity with acetaminophen (dose-dependent), dependence/withdrawal with butalbital, CNS depression, masking of serious intracranial pathology, and interaction with alcohol. |
| Food/Dietary | No specific food interactions are documented for butabarbital. However, avoid alcohol and grapefruit juice as they may alter metabolism and increase CNS depression. |
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| Fetal Monitoring | Monitor maternal liver function, renal function, and signs of barbiturate dependence. Fetal monitoring includes ultrasound for growth restriction if used chronically. Assess neonatal withdrawal signs (irritability, hypertonia) after delivery. |
| Fertility Effects | No specific studies on BUTICAPS and fertility. Phenobarbital (similar barbiturate) may induce hepatic metabolism of sex hormones and reduce efficacy of oral contraceptives. Acetaminophen and caffeine at high doses may impair fertility in animal studies; clinical relevance unknown. |
| Clinical Pearls | BUTICAPS is a brand name for butabarbital, a barbiturate used for sedation and preoperative anxiety. Due to high abuse potential and risk of dependence, it is rarely used today. Monitor for respiratory depression, especially in elderly or patients with respiratory compromise. Abrupt discontinuation can cause life-threatening withdrawal. CYP2C19 and CYP3A4 induce metabolism; co-administration with other CNS depressants increases sedation risk. |
| Patient Advice | Do not consume alcohol or other central nervous system depressants while taking this medication. · This drug can cause dependence; do not stop suddenly without medical supervision. · Avoid driving or operating heavy machinery until you know how this drug affects you. · Take exactly as prescribed; do not increase dose or frequency. · Inform your doctor of all medications you are taking, including over-the-counter drugs and herbal supplements. |