BUTALBITAL, ASPIRIN, CAFFEINE, AND CODEINE PHOSPHATE
Clinical safety rating: avoid
CNS depressants including alcohol and benzodiazepines increase sedation risk Life-threatening respiratory depression may occur especially in CYP2D6 ultra-rapid metabolizers.
Butalbital is a barbiturate that potentiates GABA-A receptor activity, producing sedation; aspirin inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, providing analgesic and antipyretic effects; caffeine is a non-selective adenosine receptor antagonist, enhancing analgesic efficacy; codeine is an opioid agonist at mu-opioid receptors, producing analgesia via central mechanisms.
| Metabolism | Butalbital: hepatic via CYP2C19 and other CYP enzymes, partly excreted unchanged; aspirin: hydrolyzed to salicylate, conjugated in liver; caffeine: hepatic via CYP1A2 (major), CYP2E1, and CYP3A4; codeine: hepatic via CYP2D6 to morphine (active), CYP3A4 to norcodeine, and glucuronidation. |
| Excretion | Codeine and its metabolites (morphine, codeine-6-glucuronide, norcodeine) are primarily excreted renally (>90%). Aspirin (acetylsalicylic acid) is hydrolyzed to salicylic acid, which is eliminated renally (75% as salicyluric acid, 10% as salicylic acid, 15% as other metabolites). Caffeine is largely metabolized in the liver and excreted renally (<3% unchanged). Butalbital is eliminated renally as metabolites and unchanged drug (about 60-70% as metabolites, 30-40% unchanged). Biliary/fecal elimination is minimal for all components. |
| Half-life | Butalbital: 35-50 hours; Aspirin: 15-20 minutes (parent), salicylic acid: 2-3 hours at low doses, 15-30 hours at high doses; Caffeine: 3-7 hours; Codeine: 2.5-4 hours, morphine: 1.5-3.5 hours. Clinical context: Butalbital's long half-life contributes to prolonged sedation and risk of accumulation with repeated dosing. |
| Protein binding | Butalbital: 20-30% (albumin); Aspirin: dose-dependent, 50-80% to albumin; Caffeine: 25-35% (albumin); Codeine: 20-25% (albumin). |
| Volume of Distribution | Butalbital: 0.5-0.6 L/kg; Aspirin: 0.15-0.2 L/kg; Caffeine: 0.6-1.0 L/kg; Codeine: 3-6 L/kg. Clinical meaning: High Vd for codeine indicates extensive tissue distribution. |
| Bioavailability | Oral: Butalbital ~90%; Aspirin 80-100% (first-pass hydrolysis to salicylic acid); Caffeine ~100%; Codeine ~60-90% (first-pass metabolism to morphine). |
| Onset of Action | Oral: Codeine component effects (analgesia, antitussive) begin within 30-60 minutes. Aspirin analgesic effect starts within 5-30 minutes. Caffeine stimulation onset in 30-60 minutes. Butalbital sedative effect onset in 30-60 minutes. |
| Duration of Action | Analgesic effect of codeine lasts 4-6 hours; caffeine stimulation persists 3-6 hours; butalbital sedation lasts 4-6 hours but may extend due to long half-life. Caution: Prolonged use may lead to tolerance and dependence. |
1-2 capsules (each containing butalbital 50 mg, aspirin 325 mg, caffeine 40 mg, and codeine phosphate 30 mg) orally every 4 hours as needed, not to exceed 6 capsules per day.
| Dosage form | CAPSULE |
| Renal impairment | CrCl 10-50 mL/min: Administer at 75% of usual dose every 6 hours; CrCl <10 mL/min: Administer at 50% of usual dose every 6 hours. |
| Liver impairment | Child-Pugh Class A: No adjustment; Child-Pugh Class B: Reduce dose by 50% and extend interval to every 6 hours; Child-Pugh Class C: Contraindicated. |
| Pediatric use | Not recommended for children under 12 years; for adolescents 12-18 years: 1 capsule orally every 4 hours as needed, not to exceed 4 capsules per day. |
| Geriatric use | Initiate at lowest effective dose; consider reducing dose by 50% and extending interval to every 6 hours due to increased risk of respiratory depression, renal impairment, and aspirin-induced gastrointestinal bleeding. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
CNS depressants including alcohol and benzodiazepines increase sedation risk Life-threatening respiratory depression may occur especially in CYP2D6 ultra-rapid metabolizers.
| FDA category | Positive |
| Breastfeeding | Aspirin and caffeine are excreted in breast milk; codeine is excreted in low amounts but may cause CNS depression in infants, especially in CYP2D6 ultrarapid metabolizers. Butalbital is excreted in low amounts. M/P ratio: Not established for this combination; codeine M/P ratio approximately 0.2-0.4. Use with caution; monitor infant for sedation, respiratory depression, poor feeding. |
■ FDA Black Box Warning
Risk of medication overuse headache; codeine: risk of addiction, abuse, misuse, life-threatening respiratory depression, neonatal opioid withdrawal syndrome, and risks from concomitant use with benzodiazepines or other CNS depressants.
| Common Effects | cough |
| Serious Effects |
Hypersensitivity to any component; pediatric patients with chickenpox or influenza-like illness (aspirin); significant respiratory depression; acute or severe bronchial asthma; GI obstruction; suspected surgical abdomen; breastfeeding (codeine); concurrent use with MAOIs or within 14 days; porphyria (barbiturates).
| Precautions | Risk of Reye's syndrome with aspirin in children/viral illness; avoid exceeding recommended dosage due to rebound headache; GI bleeding risk with aspirin; opioid-induced respiratory depression, misuse, abuse, addiction; codeine use in children post-tonsillectomy/adenoidectomy; impaired alertness; risk of serotonin syndrome with serotonergic drugs; barbiturate dependence; caffeine withdrawal headache; hepatic/renal impairment; co-administration with alcohol or CNS depressants. |
Loading safety data…
| Teratogenic Risk |
| First trimester: Aspirin associated with increased risk of gastroschisis; codeine may increase risk of congenital malformations (orofacial clefts, cardiac defects) based on some studies. Second trimester: Risk of miscarriage with NSAIDs; codeine not clearly associated. Third trimester: Aspirin and codeine associated with premature closure of ductus arteriosus, oligohydramnios, neonatal hemorrhage, and respiratory depression; butalbital may cause neonatal withdrawal. Overall: Combination product has multiple teratogenic components; avoid in pregnancy unless benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal blood pressure, renal function, liver function, and signs of bleeding. Fetal monitoring: ultrasound for growth, amniotic fluid volume, and ductus arteriosus patency in third trimester. Neonatal monitoring for withdrawal symptoms (butalbital, codeine) and respiratory depression. |
| Fertility Effects | Aspirin and other NSAIDs may impair female fertility by inhibiting prostaglandin synthesis, potentially disrupting ovulation and implantation. Effect is reversible upon discontinuation. Codeine and butalbital may cause hormonal alterations but data are limited. |
| Food/Dietary | Avoid alcohol. High-fat meals may delay absorption. Avoid excessive caffeine intake from diet (coffee, tea, soda) to prevent additive stimulation. Maintain adequate hydration to reduce salicylate renal toxicity risk. |
| Clinical Pearls | Combination analgesic with opioid and non-opioid components. Hepatotoxicity risk from aspirin in children and adolescents (Reye syndrome). Measure serum salicylate and acetaminophen levels in overdose, but codeine is a prodrug requiring CYP2D6 metabolism; poor metabolizers may have reduced efficacy while ultra-rapid metabolizers risk toxicity. Avoid in patients with G6PD deficiency (aspirin-induced hemolysis). Caffeine may potentiate analgesia but also cause CNS stimulation and dependence. Prescribe with caution in elderly due to fall risk. |
| Patient Advice | This medication contains codeine, which can be habit-forming; use only as prescribed. · Do not take with other products containing acetaminophen, aspirin, or caffeine. · Avoid alcohol; may increase risk of liver damage and sedation. · Stop use and seek medical attention if you experience ringing in ears, severe nausea/vomiting, or signs of Reye syndrome (children). · Do not drive or operate machinery until you know how this drug affects you. · Keep out of reach of children; accidental overdose may be fatal. |