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Acetaminophen, Isometheptene, and Dichloralphenazone


Related terms
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    Related terms

      • It is used to treat headaches.
      • Acetaminophen blocks chemicals that cause pain.
      • Isometheptene may lower headache pain.
      • Dichloralphenazone calms the brain.


      How to take

      • Do not take more than 5 capsules a day for a migraine or 8 capsules a day for a tension headache.
      • Take with or without food. Take with food if it causes an upset stomach.

      Missed Dose

      • Take a missed dose as soon as you think about it.
      • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
      • Do not take 2 doses at the same time or extra doses.
      • Many times this drug is taken on an as needed basis.


      • Store at room temperature.
      • Protect from water. Do not store in a bathroom or kitchen.



      • Sometimes drugs are not safe when you take them with certain other drugs. Taking them together can cause bad side effects. This is one of those drugs. Be sure to talk to your doctor about all the drugs you take.


      • If you have an allergy to acetaminophen, isometheptene, dichloralphenazone, or any other part of this drug.
      • Tell your doctor if you are allergic to any drugs. Make sure to tell about the allergy and what signs you had. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
      • If you have any of these health problems: Glaucoma, heart disease, high blood pressure, liver disease, or poor kidney function.
      • If you have taken isocarboxazid, phenelzine, or tranylcypromine in the last 14 days. Monoamine oxidase inhibitors (eg, isocarboxazid, phenelzine, and tranylcypromine) must be stopped 14 days before this drug is started. Taking both at the same time could cause risky high blood pressure.


      • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
      • Avoid other sources of acetaminophen. An overdose may cause problems.
      • Check all drugs you are taking with your doctor. This drug may not mix well with some other drugs.
      • Avoid or limit drinking wine, beer, or mixed drinks to less than 3 drinks a day. Drinking too much alcohol may raise your chance of liver disease.
      • Be careful if you have G6PD deficiency. Anemia may happen.
      • Tell your doctor if you are pregnant or plan on getting pregnant.
      • Tell your doctor if you are breast-feeding.

      Side Effects

      • Feeling dizzy. Rise slowly over a few minutes when sitting or lying down. Be careful climbing.
      • Harm to the liver may rarely happen.


      • Change in the health problem being treated. Is it better, worse, or about the same?
      • Follow up with the doctor.

      Contact a healthcare provider

      • If you think there was an overdose, call your local poison control center or ER right away.
      • Signs of a very bad reaction to the drug. These include wheezing; chest tightness; fever; itching; bad cough; blue or gray skin color; seizures; or swelling of face, lips, tongue, or throat.
      • Very bad headache.
      • Yellow skin or eyes.
      • Not able to eat.
      • Feeling very tired or weak.
      • Any rash.
      • Side effect or health problem is not better or you are feeling worse.

      General Statements

      • If you have a very bad allergy, wear an allergy ID at all times.
      • Do not share your drugs with others and do not take anyone else's drugs.
      • Keep all drugs out of the reach of children and pets.
      • Most drugs may be thrown away in household trash after mixing with coffee grounds or kitty litter and sealing in a plastic bag.
      • In Canada, take any unused drugs to the pharmacy. Also, visit to learn about the right way to get rid of unused drugs.
      • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
      • Call your doctor for help with any side effects. If in the U.S., you may also call the FDA at 1-800-FDA-1088 or if in Canada, you may also call Health Canada's Vigilance Program at 1-866-234-2345.
      • Talk with the doctor before starting any new drug, including OTC, natural products, or vitamins.

      Author information
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      Copyright © 2011 Natural Standard (

      The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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