Skip to Content

Acetaminophen, dichloralphenazone, and isometheptene

Generic Name: acetaminophen, dichloralphenazone, and isometheptene (a SEET a MIN oh fen, dye KLOR al FEN a zone, EYE soe me THEP teen)
Brand Name: Midrin, Migrazone, ...show all 19 brand names.

What is acetaminophen, dichloralphenazone, and isometheptene?

Acetaminophen is a pain reliever and a fever reducer. Dichloralphenazone is a sedative that slows the central nervous system. Isometheptene causes narrowing of blood vessels (vasoconstriction).

Acetaminophen, dichloralphenazone, and isometheptene is a combination medicine used to treat migraine headaches or severe tension headaches.

Acetaminophen, dichloralphenazone, and isometheptene may also be used for purposes not listed in this medication guide.

Important Information

You should not take this medicine if you have liver disease, severe kidney disease, glaucoma, high blood pressure, heart disease, coronary artery disease, circulation problems, peripheral vascular disease, or if you have recently had a stroke or heart attack.

Tell your doctor if you have ever had alcoholic liver disease (cirrhosis) or if you drink more than 3 alcoholic beverages per day.

Do not use this medicine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

In rare cases, acetaminophen may cause a severe skin reaction. Stop taking this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling.

Before taking this medicine

Do not use this medicine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

Tell your doctor if you have ever had alcoholic liver disease (cirrhosis) or if you drink more than 3 alcoholic beverages per day. You may not be able to take medicine that contains acetaminophen.

You should not take this medicine if you are allergic to acetaminophen (Tylenol), dichloralphenazone, isometheptene, or chloral hydrate, or if you have:

  • liver disease;

  • severe kidney disease;

  • glaucoma;

  • peripheral vascular disease such as Raynaud's syndrome;

  • high blood pressure, heart disease, coronary artery disease, blood circulation problems; or

  • if you have recently had a stroke or heart attack.

Tell your doctor if you have ever had kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

How should I take acetaminophen, dichloralphenazone, and isometheptene?

Use exactly as directed on the label, or as prescribed by your doctor. An acetaminophen overdose can damage your liver or cause death.

You may take this medication with or without food.

To treat migraine headache pain:

  • Take the first dose of this medication as soon as you notice headache symptoms, or after an attack has already begun.

  • If your headache does not completely go away, take 1 capsule every hour until you feel relief.

  • Do not take more than a total of 5 capsules in any 12-hour period to treat a migraine.

  • If you still have migraine symptoms after taking a total of 5 capsules, call your doctor.

To treat tension headache pain:

  • Take the first dose of this medication as soon as you notice tension headache symptoms.

  • If your headache does not completely go away, take 1 capsule every 4 hours until you feel relief.

  • Do not take more than a total of 8 capsules in any 24-hour period to treat a tension headache.

  • If you still have tension headache pain after taking a total of 8 capsules, call your doctor.

Call your doctor if this medicine seems to stop working as well, if your headaches get worse, or you have more than 2 headaches per week.

Do not stop using this medicine suddenly after long-term use, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using acetaminophen, dichloralphenazone, and isometheptene.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Since acetaminophen, dichloralphenazone, and isometheptene is used when needed, it does not have a daily dosing schedule. Call your doctor if your symptoms do not improve after using acetaminophen, dichloralphenazone, and isometheptene.

Do not take more than 5 capsules in 12 hours to treat a migraine, or 8 capsules in 24 hours to treat a tension headache.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of acetaminophen can damage your liver or cause death.

The first signs of an acetaminophen overdose include loss of appetite, nausea, vomiting, stomach pain, sweating, and confusion or weakness. Later symptoms may include pain in your upper stomach, dark urine, and yellowing of your skin or the whites of your eyes.

What should I avoid while taking acetaminophen, dichloralphenazone, and isometheptene?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid drinking alcohol. It may increase your risk of liver damage while taking acetaminophen.

Ask a doctor or pharmacist before using any other pain, cold, allergy, or sleep medication. Acetaminophen (sometimes abbreviated as APAP) is contained in many combination medicines. Taking certain products together can cause you to get too much acetaminophen which can lead to a fatal overdose. Check the label to see if a medicine contains acetaminophen or APAP.

acetaminophen, dichloralphenazone, and isometheptene side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

In rare cases, acetaminophen may cause a severe skin reaction that can be fatal, even if you took acetaminophen in the past and had no reaction. Stop taking this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling.

Stop using this medicine and call your doctor at once if you have:

  • severe drowsiness or restless feeling, feeling like you might pass out;

  • fast, slow, or uneven heart rate;

  • rapid breathing, weak or shallow breathing;

  • little or no urinating;

  • cold feeling; or

  • liver problems--nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Acetaminophen, dichloralphenazone, and isometheptene dosing information

Usual Adult Dose for Headache:

Migraine Headache: 2 capsules at once orally, followed by one capsule every hour until relieved, up to 5 capsules within a 12 hour period

Tension Headache: 1 to 2 capsules every 4 hours, up to 8 capsules a day

What other drugs will affect acetaminophen, dichloralphenazone, and isometheptene?

Taking this medicine with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Other drugs may affect acetaminophen, dichloralphenazone, and isometheptene, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.