Acetaminophen, Isometheptene, and Dichloralphenazone

Pronunciation (a seet a MIN oh fen, eye soe me THEP teen, & dye KLOR al FEN a zone)

U.S. Brand Names Midrin®; Migratine®

Synonyms Acetaminophen, Dichloralphenazone, and Isometheptene; Dichloralphenazone, Acetaminophen, and Isometheptene; Dichloralphenazone, Isometheptene, and Acetaminophen; Isometheptene, Acetaminophen, and Dichloralphenazone; Isometheptene, Dichloralphenazone, and Acetaminophen

Generic Available Yes

Pharmacologic Category Analgesic, Miscellaneous

Use Relief of migraine and tension headache

Restrictions C-IV

Pregnancy Risk Factor B

Contraindications Hypersensitivity to acetaminophen, isometheptene, dichloralphenazone, or any component of the formulation; glaucoma; severe renal disease; hypertension; organic heart disease; hepatic disease; MAO inhibitor therapy

Adverse Reactions Frequency not defined.

Central nervous system: Transient dizziness

Dermatological: Rash

Ethanol/Nutrition/Herb Interactions Ethanol: Excessive intake of ethanol may increase the risk of acetaminophen-induced hepatotoxicity. Avoid ethanol or limit to <3 drinks/day.

Dosage Adults: Oral:

Migraine headache: 2 capsules to start, followed by 1 capsule every hour until relief is obtained (maximum: 5 capsules/12 hours)

Tension headache: 1-2 capsules every 4 hours (maximum: 8 capsules/24 hours)

Dental Health: Effects on Dental Treatment No effects or complications reported

Dental Health: Vasoconstrictor/Local Anesthetic Precautions No information available to require special precautions

Dental Comment Should not exceed 5 g in 12 hours; may cause drowsiness; avoid ethanol and other CNS depressants

Mental Health: Effects on Mental Status May cause drowsiness or dizziness

Mental Health: Effects on Psychiatric Treatment Contraindicated with MAO inhibitor

Dosage Forms Capsule: Acetaminophen 325 mg, isometheptene mucate 65 mg, dichloralphenazone 100 mg

Barker JD Jr, de Carle DJ, and Anuras S, "Chronic Excessive Acetaminophen Use in Liver Damage,"Ann Intern Med, 1977, 87(3):299-301.

Dionne RA, Campbell RA, Cooper SA, et al, "Suppression of Postoperative Pain by Preoperative Administration of Ibuprofen in Comparison to Placebo, Acetaminophen, and Acetaminophen Plus Codeine,"J Clin Pharmacol, 1983, 23(1):37-43.

Licht H, Seeff LB, and Zimmerman HJ, "Apparent Potentiation of Acetaminophen Hepatotoxicity by Alcohol,"Ann Intern Med, 1980, 92(4):511.