• Home
• Learning Centers
• Diseases & Conditions
• Drugs
• Symptoms
• Videos
• Health Experts
• Tools
• Marketplace

• Basic Info
• Top Questions
• Interactions

What is acetaminophen, dichloralphenazone, and isometheptene?
Acetaminophen is a pain reliever and a fever reducer. Dichloralphenazone is a sedative that slows down your central nervous system (brain and nerve impulses), causing relaxation and pain relief. Isometheptene causes constriction (narrowing) of blood vessels (arteries and veins). This is important in the treatment of headaches. The combination, acetaminophen, dichloralphenazone, and isometheptene, is used to treat tension (or muscle contraction) and vascular (migraine) headaches. Acetaminophen, dichloralphenazone, and isometheptene may also be used for purposes other than those listed in this medication guide.

Back to Top

What are the possible side effects of acetaminophen, dichloralphenazone, and isometheptene?

If you experience any of the following serious side effects, stop taking acetaminophen, dichloralphenazone, and isometheptene and seek emergency medical attention:

• an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);

• liver damage (yellowing of the skin or eyes, abdominal pain); or

• blood problems (easy or unusual bleeding or bruising).

These side effects are very rare and are not likely to occur during proper treatment with acetaminophen, dichloralphenazone, and isometheptene.

Other, less serious side effects may be more likely to occur. Continue to take acetaminophen, dichloralphenazone, and isometheptene and talk to your doctor if you experience

• nausea;

• dizziness, tiredness, or lightheadedness; or

• a rash.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

Back to Top

How should I take acetaminophen, dichloralphenazone, and isometheptene?
Take acetaminophen, dichloralphenazone, and isometheptene exactly as directed by your doctor or follow the instructions on the package. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. Never take more acetaminophen, dichloralphenazone, and isometheptene than is prescribed for you. If your pain is not being adequately treated, talk to your doctor. Do not share this medication with anyone else.

Back to Top

What is the most important information I should know about acetaminophen, dichloralphenazone, and isometheptene?
Use caution when driving, operating machinery, or performing other hazardous activities. Dichloralphenazone may cause drowsiness or dizziness. If you experience drowsiness or dizziness, avoid these activities. Avoid alcohol. Alcohol taken during therapy with acetaminophen, dichloralphenazone, and isometheptene can be very damaging to your liver and can increase drowsiness and dizziness. Never take more acetaminophen, dichloralphenazone, and isometheptene than is prescribed for you. If your pain is not being adequately treated, talk to your doctor.

Back to Top

What happens if I miss a dose?
Take the missed dose as soon as you remember. Do not take a double dose of this medication. Wait the prescribed amount of time before taking your next dose. If you are taking acetaminophen, dichloralphenazone, and isometheptene on an as-needed basis, missing a dose is not usually a problem. Take the missed dose as soon as you remember and do not take another dose for the amount of time prescribed by your doctor.

Back to Top

What other drugs will affect acetaminophen, dichloralphenazone, and isometheptene?
Do not take acetaminophen, dichloralphenazone, and isometheptene if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the last 14 days. Dangerous side effects could result. Dichloralphenazone may increase the effects of other drugs that cause drowsiness, including antidepressants, alcohol, antihistamines, sedatives (used to treat insomnia), pain relievers, anxiety medicines, and muscle relaxants. Tell your doctor about all medicines that you are taking, and do not take any medicine unless your doctor approves.

Back to Top

Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Acetaminophen has not been formally assigned to a pregnancy category by the FDA. It is routinely used for short-term pain relief and fever in all stages of pregnancy. Acetaminophen is believed to be safe in pregnancy when used intermittently for short durations. Dichloralphenazone has not been formally assigned to a pregnancy category by the FDA. Animal studies have not been reported. There are no controlled data in human pregnancy. Isometheptene has not been formally assigned to a pregnancy category by the FDA. Animal studies have not been reported. There are no controlled data in human pregnancy. Acetaminophen/dichloralphenazone/isometheptene should only be given during pregnancy when need has been clearly established.

Two cases of acetaminophen overdose in late pregnancy have been reported. In both cases neither the neonate nor the mother suffered hepatic toxicity. Investigations have revealed conflicting results with regards to the pharmacokinetic disposition of acetaminophen in pregnant women. One study has suggested that the oral clearance of acetaminophen is 58% higher and the elimination half-life is 28% longer in pregnant women compared to non-pregnant women. Another study has suggested that the elimination half-life is not different in patients who are pregnant. That study also suggested that the volume of distribution of acetaminophen may be higher in pregnant women. One study has suggested that acetaminophen in typical oral doses may result in a reduced production of prostacyclin in pregnant women. That study also suggested that acetaminophen does not affect thromboxane production.

Acetaminophen is excreted into human milk in small concentrations. One case of a rash has been reported in a nursing infant. Acetaminophen is considered compatible with breast-feeding by the American Academy of Pediatrics. Dichloralphenazone is a prodrug composed of phenazone and chloral hydrate. Both phenazone and the active metabolite of chloral hydrate, trichloroethanol, are excreted into human milk. Milk concentrations of trichoroethanol have been reported at 60% to 80% of maternal serum levels. The only effect reported in the infant was mild morning drowsiness. There are no data on the excretion of isometheptene into human milk.

One small study on acetaminophen has reported that following a 1000 mg dose of acetaminophen to nursing mothers, nursing infants receive less than 1.85% of the weight-adjusted maternal oral dose.

Back to Top

What does my medication look like?
Acetaminophen, dichloralphenazone, and isometheptene is available with a prescription under several brand and generic names. Ask your pharmacist any questions you have about this medication especially if it is new to you.

Back to Top

What happens if I overdose?
Seek emergency medical attention. Symptoms of an acetaminophen, dichloralphenazone, and isometheptene overdose are unknown but drowsiness and dizziness would be expected.

Back to Top

What should I discuss with my healthcare provider before taking acetaminophen, dichloralphenazone, and isometheptene?
Do not take acetaminophen, dichloralphenazone, and isometheptene without first talking to your doctor if you drink more than three alcoholic beverages per day or if you have had alcoholic liver disease. You may not be able to take acetaminophen, dichloralphenazone, and isometheptene, or you may require a lower dose. Do not take acetaminophen, dichloralphenazone, and isometheptene if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the last 14 days. Dangerous side effects could result.

Back to Top

Can I stop taking the medication if I feel better?
If you are taking an analgesic for pain and you are no longer experiencing the pain you may stop using the medication. In general, pain medications are to be used on an as needed basis.

Back to Top

I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

Back to Top