ESGIC-PLUS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ESGIC-PLUS (ESGIC-PLUS).
Esgic-Plus is a combination of acetaminophen (analgesic/antipyretic via COX inhibition and central action), butalbital (barbiturate that enhances GABA-A receptor activity), and caffeine (adenosine receptor antagonist and CNS stimulant). The mechanism for treating tension headache is attributed to the synergistic effects of these components.
| Metabolism | Acetaminophen: primarily hepatic via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation (SULT1A1, SULT1A3); minor oxidation by CYP2E1, CYP3A4, and CYP1A2 to toxic NAPQI. Butalbital: hepatic via hydroxylation and glucuronidation; exhibits first-pass metabolism. Caffeine: hepatic via CYP1A2 (85%) to paraxanthine; also N-acetylation and oxidation. |
| Excretion | Butalbital: 60-90% renal as unchanged drug and metabolites, 10-40% fecal via biliary elimination. Acetaminophen: ~85% renal as glucuronide (45-55%), sulfate (25-35%), and cysteine conjugates (4-15%); 2-4% unchanged. Caffeine: ~85-90% renal as metabolites (1-methylxanthine, 1-methyluric acid, 1,7-dimethylxanthine); 1-3% unchanged. |
| Half-life | Butalbital: 35-70 hours in adults; prolonged in hepatic/renal impairment. Acetaminophen: 2-3 hours in adults; extended in overdose (potential hepatotoxicity). Caffeine: 3-6 hours in adults; increased in pregnancy or liver disease. |
| Protein binding | Butalbital: 25-30% bound to albumin. Acetaminophen: 10-25% bound to albumin (higher in overdose). Caffeine: 25-36% bound to albumin. |
| Volume of Distribution | Butalbital: 0.5-0.8 L/kg, moderately tissue distributed. Acetaminophen: 0.7-1.0 L/kg, widespread including CNS. Caffeine: 0.5-0.7 L/kg, distributed in total body water. |
| Bioavailability | Oral: Butalbital ~85-95%; Acetaminophen ~75-85% (first-pass metabolism); Caffeine ~99% (almost complete). |
| Onset of Action | Oral: Butalbital sedation within 30-60 minutes; acetaminophen analgesia within 30-45 minutes; caffeine stimulation within 15-30 minutes. |
| Duration of Action | Butalbital: 4-6 hours for sedation; acetaminophen: 4-6 hours for analgesia; caffeine: 3-5 hours for stimulant effect. Clinical effects may persist longer due to butalbital accumulation. |
1-2 capsules (acetaminophen 500 mg, butalbital 50 mg, caffeine 40 mg per capsule) orally every 4 hours as needed, not exceeding 6 capsules per day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-89 mL/min: No adjustment. GFR 15-29 mL/min: Extend interval to every 6 hours; avoid in severe impairment (GFR <15 mL/min) due to butalbital accumulation. |
| Liver impairment | Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose by 50% or extend interval to every 6 hours. Child-Pugh C: Contraindicated due to risk of hepatic encephalopathy and acetaminophen toxicity. |
| Pediatric use | Not recommended for pediatric patients; safety and efficacy not established. For children >12 years, consider adult dosing on a case-by-case basis. |
| Geriatric use | Initiate at lower dose (1 capsule every 6 hours) and monitor for sedation, confusion, or hepatotoxicity. Reduce total daily dose if renal or hepatic impairment present. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ESGIC-PLUS (ESGIC-PLUS).
| Breastfeeding | Acetaminophen and caffeine enter breast milk in small amounts (M/P ratio ~0.1-0.2 and 0.5-0.7 respectively); butalbital is excreted with M/P ratio ~0.5. Concentrations are low, but risk of neonatal sedation and withdrawal with chronic use. Not recommended unless benefit outweighs risk. |
| Teratogenic Risk | FDA Pregnancy Category C. First trimester: butalbital is associated with increased risk of congenital malformations (cleft palate, urogenital anomalies) based on barbiturate class effects; acetaminophen and caffeine are generally considered low risk. Second/third trimester: prolonged use may lead to neonatal withdrawal (irritability, tremors) and potential neonatal hemorrhage (due to acetaminophen's effect on vitamin K-dependent clotting factors). |
■ FDA Black Box Warning
Acetaminophen has been associated with cases of acute liver failure, sometimes resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4000 mg per day, and often involve more than one acetaminophen-containing product.
| Serious Effects |
["Hypersensitivity to any component","Acute intermittent porphyria (butalbital)","Severe hepatic impairment","Concurrent use of other acetaminophen-containing products (risk of overdose)","Breastfeeding (butalbital and caffeine pass into breast milk and may cause adverse effects in the infant)"]
| Precautions | ["Hepatotoxicity: avoid exceeding 4000 mg acetaminophen per day; severe liver injury may occur with chronic use even at therapeutic doses.","Respiratory depression: butalbital can cause dose-related respiratory depression.","Drug dependence: butalbital has abuse potential and may cause withdrawal syndrome upon discontinuation.","Interaction with alcohol: increased risk of hepatotoxicity with chronic alcohol use.","Renal impairment: use with caution in severe impairment.","Pregnancy: avoid use, especially during third trimester, due to potential neonatal withdrawal and respiratory depression."] |
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| Fetal Monitoring | Monitor maternal blood pressure, fetal growth and development via ultrasound. Assess for signs of neonatal withdrawal if used near term. Check maternal liver function tests periodically due to acetaminophen. |
| Fertility Effects | Limited data. Caffeine may reduce female fertility at high doses. Butalbital and acetaminophen have no known significant impact on fertility. |