Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AXOTAL vs FIORINAL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Axotal contains butalbital, a barbiturate that enhances GABA-A receptor activity, and acetaminophen, an analgesic and antipyretic whose mechanism is not fully understood but may involve COX inhibition and activation of descending serotonergic pathways.
FIORINAL is a combination of butalbital (barbiturate), aspirin (NSAID), and caffeine. Butalbital potentiates GABA-A receptor activity, producing sedative-hypnotic effects. Aspirin inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, which provides analgesic and antipyretic effects. Caffeine is a non-selective adenosine receptor antagonist, enhancing analgesic efficacy.
Tension headache
Relief of tension-type headache,Relief of migraine headache (off-label)
Each tablet: butalbital 50 mg, acetaminophen 300-500 mg, caffeine 40 mg. 1-2 tablets orally every 4 hours as needed, not exceeding 6 tablets per day.
1-2 capsules (butalbital 50 mg, acetaminophen 300 mg, caffeine 40 mg) orally every 4 hours as needed, not exceeding 6 capsules per day.
Terminal elimination half-life is 2-4 hours in patients with normal renal function; prolonged to 8-12 hours in severe renal impairment (Cr Cl <30 m L/min).
Butalbital 35-50 hours, aspirin 15-20 minutes (salicylate 2-3 hours at low doses, >20 hours at high doses), caffeine 3-5 hours. Prolonged in hepatic/renal impairment.
Butalbital is metabolized primarily by CYP2C19; acetaminophen is metabolized mainly via glucuronidation by UGT1A1 and UGT1A6, sulfation by SULT1A1, and minor oxidation by CYP2E1.
Butalbital is extensively metabolized in the liver via hydroxylation and glucuronidation, primarily by CYP2C9 and CYP2C19. Aspirin is hydrolyzed to salicylic acid, then conjugated with glycine (salicyluric acid) and glucuronidated. Caffeine is metabolized by CYP1A2 to paraxanthine, theobromine, and theophylline.
Renal excretion of unchanged drug (60-70%) and glucuronide conjugates (10-20%); biliary excretion (5-10%); fecal elimination (<10%).
Renal: 60% butalbital (mostly unchanged), 10% aspirin (salicylates, majorly as metabolites), 3% caffeine (metabolites and unchanged). Fecal: <5% overall.
98-99% bound primarily to albumin; minor binding to alpha-1-acid glycoprotein.
Butalbital 20-40% (albumin), aspirin 80-90% (albumin, concentration-dependent), caffeine 25-36% (albumin).
0.15-0.25 L/kg, indicating distribution mainly in extracellular fluid and limited tissue penetration.
Butalbital 0.8 L/kg, aspirin 0.15-0.2 L/kg, caffeine 0.6-0.8 L/kg. Indicates extensive tissue distribution for butalbital and caffeine.
Oral: 85-95%; intramuscular: 90-100%; intravenous: 100%.
Oral: butalbital ~100%, aspirin 50-75% (first-pass metabolism), caffeine ~100%.
No specific guidelines; contraindicated in severe renal impairment (Cr Cl <30 m L/min). Use with caution in mild-moderate impairment due to acetaminophen and butalbital accumulation.
No specific guidelines; contraindicated in severe renal impairment (Cr Cl <30 m L/min) due to acetaminophen accumulation. Use with caution in moderate impairment.
Contraindicated in Child-Pugh Class C (severe hepatic impairment). In Child-Pugh A or B, reduce dose or extend interval; maximum acetaminophen 2000 mg/day, avoid butalbital if possible.
Contraindicated in severe hepatic impairment (Child-Pugh Class C). For mild to moderate (Child-Pugh A or B), reduce dose by 50% or extend dosing interval.
Not recommended for children under 12 years. For ages 12-18: same as adult dose (1-2 tablets) but limit to 4 tablets per day and monitor for sedation.
Not recommended for pediatric use; safety and efficacy not established.
Start at lower dose (1 tablet every 6 hours) due to increased sensitivity to butalbital (c NS depression, falls) and acetaminophen hepatotoxicity risk; limit to 4 tablets per day, avoid in frail elderly.
Start at lowest effective dose (e.g., 1 capsule every 4 hours) due to increased sensitivity to butalbital (sedation, confusion) and risk of acetaminophen hepatotoxicity; maximum daily acetaminophen dose 2 g.
Acetaminophen has been associated with cases of acute liver failure, sometimes resulting in liver transplant and death. Hepatotoxicity is usually associated with doses exceeding 4000 mg per day and often involves more than one acetaminophen-containing product.
None.
Hepatotoxicity with acetaminophen overdose; risk of rhabdomyolysis, angioedema, Stevens-Johnson syndrome; butalbital dependence and withdrawal; CNS depression; impairment of mental or physical abilities; avoid concurrent alcohol use.
Risk of Reye's syndrome in children with viral illness,Aspirin hypersensitivity (e.g., asthma, nasal polyps),Gastrointestinal bleeding and ulceration,Hepatic impairment due to butalbital metabolism,Caffeine overdose from excessive use,Dependence and withdrawal with prolonged butalbital use
Hypersensitivity to barbiturates or acetaminophen; porphyria; severe hepatic impairment; respiratory depression; history of substance abuse.
Hypersensitivity to butalbital, aspirin, or caffeine,Active peptic ulcer disease,Hemophilia or bleeding disorders,Concomitant use of anticoagulants,Children with chickenpox or influenza-like symptoms (risk of Reye's syndrome),Severe hepatic or renal impairment,Porphyria
Avoid alcohol intake; concurrent use increases risk of acetaminophen hepatotoxicity. Grapefruit juice may increase caffeine levels; limit consumption. High-fat meals may delay absorption of butalbital. Maintain adequate hydration; caffeine has mild diuretic effect.
Avoid excessive caffeine intake from coffee, tea, energy drinks, or chocolate as it may compound caffeine's stimulant effects and increase anxiety or insomnia. Alcohol should be strictly avoided due to additive CNS depression and increased GI bleeding risk with aspirin. No specific food restrictions besides moderation of caffeine-containing foods.
Pregnancy Category D. First trimester: Risk of cardiovascular malformations (e.g., Ebstein anomaly), neural tube defects, and oral clefts increased with lithium exposure. Second and third trimesters: Increased risk of fetal/neonatal toxicity including cardiac arrhythmias, hypoglycemia, polyhydramnios, preterm birth, and neonatal goiter. Avoid if possible; weigh risks vs. benefits.
First trimester: Butalbital is associated with neural tube defects, cleft palate; aspirin increases risk of gastroschisis, cardiac defects. Second trimester: Aspirin may cause premature closure of ductus arteriosus. Third trimester: Aspirin increases risk of intracranial hemorrhage, premature closure of ductus arteriosus; butalbital may cause neonatal withdrawal. Caffeine is not a major teratogen but high doses may increase miscarriage risk.
Lithium is excreted into human milk (M/P ratio 0.3-0.8). Breastfeeding is not recommended due to risk of neonatal toxicity (hypotonia, hypothermia, cyanosis, ECG changes). Monitor infant serum levels if breastfeeding is continued.
Aspirin excreted in milk (M/P ratio ~0.03-0.3); risk of Reye syndrome. Butalbital excreted in low amounts; may cause neonatal sedation. Caffeine excreted (M/P ~0.5-0.7); may cause irritability. Avoid breastfeeding during chronic use.
Dose adjustments are often necessary due to increased glomerular filtration rate and expanded plasma volume. Monitor serum levels closely (every 2-4 weeks in second and third trimesters). Dose may need to be increased or given in divided doses (e.g., 3 times daily) due to faster clearance. Postpartum: reduce dose promptly to pre-pregnancy levels within 24 hours after delivery to avoid toxicity from narrowed volume of distribution.
Due to increased renal clearance and volume of distribution, butalbital may require dose increase; aspirin may need higher doses due to increased plasma volume; no specific adjustment for caffeine. Monitor clinical response and toxicity.
AXOTAL (butalbital/acetaminophen/caffeine) is a combination analgesic for tension-type headaches. Butalbital is a barbiturate with addiction potential; limit use to less than 2 days per week to avoid medication overuse headache (MOH). Acetaminophen hepatic toxicity risk increases with chronic alcohol use or pre-existing liver disease. Caffeine may cause withdrawal headaches upon abrupt cessation.
FIORINAL (butalbital/aspirin/caffeine) is a barbiturate-containing combination analgesic. Due to butalbital's high abuse potential and risk of withdrawal, it is reserved for tension-type headaches refractory to non-barbiturate therapies. Monitor for signs of barbiturate dependence, and limit quantity dispensed. Avoid in patients with porphyria, severe hepatic impairment, or hemorrhagic disorders (aspirin component). Caffeine may exacerbate anxiety or insomnia.
Do not exceed 4 tablets per day to avoid acetaminophen overdose (max 4000 mg/day).,Avoid alcohol while taking this medication due to risk of liver damage.,This drug can be habit-forming; use only as prescribed for headache attacks, not for prophylaxis.,May cause drowsiness or dizziness; avoid driving or operating machinery until you know how you react.,Discontinue and seek medical help if you experience signs of liver injury (jaundice, dark urine) or allergic reaction (rash, swelling).,Caffeine content may interfere with sleep or exacerbate anxiety; limit other caffeine sources.
This medication contains butalbital, which can be habit-forming; do not exceed prescribed dose or duration.,Avoid alcohol and other CNS depressants (e.g., benzodiazepines, opioids) as they increase sedation and respiratory depression risk.,Do not drive or operate heavy machinery until you know how this drug affects you.,Take with food to reduce stomach upset; if you experience black or bloody stools, stop and seek immediate medical attention (signs of GI bleeding from aspirin).,Do not use more than directed; sudden discontinuation can cause withdrawal symptoms (anxiety, tremors, seizures).,Keep out of reach of children; overdose may be fatal.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about AXOTAL vs FIORINAL, answered by our medical review team.
AXOTAL is a Barbiturate Combination Analgesic that works by Axotal contains butalbital, a barbiturate that enhances GABA-A receptor activity, and acetaminophen, an analgesic and antipyretic whose mechanism is not fully understood but may involve COX inhibition and activation of descending serotonergic pathways.. FIORINAL is a Barbiturate Analgesic Combination that works by FIORINAL is a combination of butalbital (barbiturate), aspirin (NSAID), and caffeine. Butalbital potentiates GABA-A receptor activity, producing sedative-hypnotic effects. Aspirin inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, which provides analgesic and antipyretic effects. Caffeine is a non-selective adenosine receptor antagonist, enhancing analgesic efficacy.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AXOTAL and FIORINAL depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of AXOTAL is: Each tablet: butalbital 50 mg, acetaminophen 300-500 mg, caffeine 40 mg. 1-2 tablets orally every 4 hours as needed, not exceeding 6 tablets per day.. The standard adult dose of FIORINAL is: 1-2 capsules (butalbital 50 mg, acetaminophen 300 mg, caffeine 40 mg) orally every 4 hours as needed, not exceeding 6 capsules per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between AXOTAL and FIORINAL in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. AXOTAL is classified as Category C. Pregnancy Category D. First trimester: Risk of cardiovascular malformations (e.g., Ebstein anomaly), neural tube defects, and oral clefts increased with lithium exposure. Second an. FIORINAL is classified as Category C. First trimester: Butalbital is associated with neural tube defects, cleft palate; aspirin increases risk of gastroschisis, cardiac defects. Second trimester: Aspirin may cause prem. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.