What is Isometheptene / Dichloralphenazone / Acetaminophen?

Commonly Used Brand Name(s)Backprin, Be-Flex Plus, By-Ache, Cafgesic Forte, Combiflex, Combiflex ES, Durabac, Durabac Forte, Genaced, Goody's Fast Pain Relief, Levacet, Pain-Off

OverviewTOP

Acetaminophen and salicylate combination medicines relieve pain and reduce fever. They may be used to relieve occasional pain caused by mild inflammation or arthritis (rheumatism). The acetaminophen, aspirin, and caffeine combination also may be used to relieve pain associated with migraine headaches.

Neither acetaminophen nor salicylamide is as effective as aspirin for treating chronic or severe pain, or other symptoms, caused by inflammation or arthritis. Some of these combination medicines do not contain any aspirin. Even those that do contain aspirin may not contain enough to be effective in treating these conditions.

A few reports have suggested that acetaminophen and salicylates used together may cause kidney damage or cancer of the kidney or urinary bladder. This may occur if large amounts of both medicines are taken together for a very long time. However, taking usual amounts of these combination medicines for a short time has not been shown to cause these unwanted effects. Also, these effects are not likely to occur with either acetaminophen or a salicylate used alone, even if large amounts have been taken for a long time. Therefore, for long-term use, it may be best to use either acetaminophen or a salicylate, but not both, unless you are under a doctor's care.

Before giving any of these combination medicines to a child, check the package label very carefully. Some of these medicines are too strong for use in children. If you are not certain whether a specific product can be given to a child, or if you have any questions about the amount to give, check with your health care professional.

These medicines are available without a prescription. However, your doctor may have special instructions on the proper dose of these medicines for your medical condition.

Proper UseTOP

Take this medicine with food or a full glass (8 ounces) of water to lessen the chance of stomach upset.

Unless otherwise directed by your doctor:

Do not take more of this medicine than directed on the package label. Taking too much acetaminophen may cause liver damage or lead to other medical problems because of an overdose. Also, taking too much aspirin can cause stomach problems or lead to other medical problems because of an overdose.
Children up to 12 years of age should not take this medicine more often than five times a day
Check with your doctor before taking one of these combination medicines to treat severe or chronic inflammation or arthritis (rheumatism). These combination medicines may not relieve the severe pain, redness, swelling, or stiffness caused by these conditions unless very large amounts are taken for a long time. It is best not to take acetaminophen and salicylate combination medicines in large amounts for a long time unless you are under a doctor's care.
If a combination medicine containing aspirin has a strong vinegar-like odor, do not use it. This odor means the medicine is breaking down. If you have any questions about this, check with your pharmacist.

DosingTOP

The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For oral (capsules or tablets [including caplets]) dosage forms:
- For pain, fever, or mild arthritis symptoms:
  - Adults and teenagers—The usual dose is 1 or 2 capsules or tablets every three, four, or six hours, depending on the strength of the product. Do not take any of these combination medicines for more than ten days, unless otherwise directed by your doctor
  - Children—Use and dose must be determined by your doctor.
- For migraine headaches:
  - Adults and teenagers—The usual dose is 2 tablets (250 mg acetaminophen, and 250 mg of aspirin, and 65 mg of caffeine in combination) every six hours as necessary for relief from migraine headaches. Do not take for relief of migraine headache for more than two days, unless otherwise directed by your doctor
  - Children—Use and dose must be determined by your doctor.

For oral (powder) dosage form:
- For pain, fever, or mild arthritis symptom:
  - Adults and teenagers—This medicine is very strong. Each packet of powder contains 260 mg of acetaminophen and 520 mg of aspirin (a total of 780 mg of both medicines). The usual dose is one packet of powder every four to six hours. Do not take this medicine for more than ten days, unless otherwise directed by your doctor.
  - Children—The oral powder dosage form is too strong to use in children 12 years of age or younger.

Use & StorageTOP

Keep out of the reach of children.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Do not keep outdated medicine or medicine no longer needed.

AllergiesTOP

Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

PediatricTOP

For acetaminophen: Acetaminophen has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.
For aspirin and for salicylamide: Do not give a medicine containing aspirin or salicylamide to a child with symptoms of a virus infection, especially flu or chickenpox, without first discussing its use with your child's doctor. This is very important because aspirin may cause a serious illness called Reye's syndrome in children with fever caused by a virus infection, especially flu or chickenpox. Children who do not have a virus infection may also be more sensitive to the effects of aspirin, especially if they have a fever or have lost large amounts of body fluid because of vomiting, diarrhea, or sweating. This may increase the chance of side effects during treatment.
For caffeine: There is no specific information comparing use of caffeine in children younger than 12 years of age with use in other age groups. However, caffeine is not expected to cause different side effects or problems in children than it does in adults.

GeriatricTOP

Elderly people may be more likely than younger adults to develop serious kidney problems if they take large amounts of these combination medicines for a long time. Therefore, it is best that elderly people not take this medicine for more than 5 days in a row unless they are under a doctor's care.

For acetaminophen: Acetaminophen has been tested and, in effective doses, has not been shown to cause different side effects or problems in older people than it does in younger adults.
For aspirin: People 60 years of age and older are especially sensitive to the effects of aspirin. This may increase the chance of side effects during treatment.
For caffeine: Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of caffeine in the elderly with use in other age groups.

PregnancyTOP

For acetaminophen: Studies on birth defects have not been done in humans. However, acetaminophen has not been reported to cause birth defects or other problems.
For aspirin: Studies in humans have not shown that aspirin causes birth defects. However, aspirin has been shown to cause birth defects in animals. Do not take aspirin during the last 3 months of pregnancy unless it has been ordered by your doctor. Some reports have suggested that too much use of aspirin late in pregnancy may cause a decrease in the newborn's weight and possible death of the fetus or newborn infant. However, the mothers in these reports had been taking much larger amounts of aspirin than are usually recommended. Studies of mothers taking aspirin in the doses that are usually recommended did not show these unwanted effects. However, there is a chance that regular use of aspirin late in pregnancy may cause unwanted effects on the heart or blood flow in the fetus or newborn infant. Use of aspirin during the last 2 weeks of pregnancy may cause bleeding problems in the fetus before or during delivery, or in the newborn infant. Also, too much use of aspirin during the last 3 months of pregnancy may increase the length of pregnancy, prolong labor, cause other problems during delivery, or cause severe bleeding in the mother before, during, or after delivery.
For salicylamide: Studies on birth defects have not been done in humans.
For caffeine: Studies in humans have not shown that caffeine causes birth defects. However, use of large amounts of caffeine by the mother during pregnancy may cause problems with the heart rhythm of the fetus and may affect the growth of the fetus. Studies in animals have shown that caffeine causes birth defects when given in very large doses (amounts equal to the amount of caffeine in 12 to 24 cups of coffee a day).

Breast FeedingTOP

For acetaminophen and for aspirin: Acetaminophen and aspirin pass into breast milk; however, they have not been reported to cause problems in nursing babies.
For caffeine: Caffeine (contained in some of these combination medicines) passes into breast milk in small amounts. Taking caffeine in the amounts present in these medicines has not been reported to cause problems in nursing babies. However, studies have shown that babies may appear jittery and have trouble in sleeping when their mothers drink large amounts of caffeine-containing beverages. Therefore, breast-feeding mothers who use these medicines probably should limit the amount of caffeine they take in from other medicines or from beverages

Drug InteractionsTOP

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.

Defibrotide
Dichlorphenamide
Influenza Virus Vaccine, Live
Ketorolac
Riociguat

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Acarbose
Aceclofenac
Acemetacin
Alipogene Tiparvovec
Alteplase, Recombinant
Amiloride
Amineptine
Amitriptyline
Amitriptylinoxide
Amoxapine
Amtolmetin Guacil
Anagrelide
Anisindione
Apixaban
Argatroban
Bendroflumethiazide
Benzthiazide
Betrixaban
Bivalirudin
Bromfenac
Bufexamac
Bumetanide
Celecoxib
Chlorothiazide
Chlorpropamide
Chlorthalidone
Choline Salicylate
Cilostazol
Citalopram
Clomipramine
Clonixin
Clopamide
Clopidogrel
Cyclopenthiazide
Cyclosporine
Dabigatran Etexilate
Danaparoid
Deferasirox
Desipramine
Desirudin
Desmopressin
Desvenlafaxine
Dexibuprofen
Dexketoprofen
Diazoxide
Dibenzepin
Diclofenac
Dicumarol
Diflunisal
Digoxin
Dipyrone
Dothiepin
Doxepin
Droxicam
Duloxetine
Edoxaban
Elvitegravir
Eplerenone
Eptifibatide
Escitalopram
Ethacrynic Acid
Etodolac
Etofenamate
Etoricoxib
Felbinac
Fenoprofen
Fepradinol
Feprazone
Feverfew
Floctafenine
Flufenamic Acid
Fluoxetine
Flurbiprofen
Fluvoxamine
Fondaparinux
Furosemide
Gefitinib
Ginkgo
Glimepiride
Glipizide
Glyburide
Gossypol
Heparin
Hydrochlorothiazide
Hydroflumethiazide
Ibuprofen
Imatinib
Imipramine
Indapamide
Indomethacin
Isoniazid
Ketoconazole
Ketoprofen
Ledipasvir
Lepirudin
Levomilnacipran
Lithium
Lofepramine
Lornoxicam
Loxoprofen
Lumiracoxib
Meclofenamate
Mefenamic Acid
Melitracen
Meloxicam
Metformin
Methotrexate
Methyclothiazide
Metolazone
Milnacipran
Morniflumate
Mycophenolate Mofetil
Mycophenolic Acid
Nabumetone
Naproxen
Nateglinide
Nefazodone
Nepafenac
Nicorandil
Niflumic Acid
Nimesulide
Nimesulide Beta Cyclodextrin
Nortriptyline
Opipramol
Oxaprozin
Oxyphenbutazone
Parecoxib
Paroxetine
Pazopanib
Peginterferon Alfa-2b
Pemetrexed
Pentosan Polysulfate Sodium
Pentoxifylline
Phenindione
Phenprocoumon
Phenylbutazone
Phenytoin
Piketoprofen
Piracetam
Piroxicam
Pixantrone
Pneumococcal 13-Valent Vaccine, Diphtheria Conjugate
Polythiazide
Pralatrexate
Pranoprofen
Prasugrel
Proglumetacin
Propyphenazone
Proquazone
Protein C
Protriptyline
Quinine
Raltegravir
Regadenoson
Repaglinide
Reteplase, Recombinant
Rilpivirine
Rivaroxaban
Rofecoxib
Salicylic Acid
Salsalate
Sertraline
Sodium Salicylate
Spironolactone
Sulindac
Tacrolimus
Tenoxicam
Tianeptine
Tiaprofenic Acid
Ticagrelor
Ticlopidine
Tirofiban
Tolazamide
Tolbutamide
Tolfenamic Acid
Tolmetin
Torsemide
Treprostinil
Triamterene
Trichlormethiazide
Trimipramine
Valdecoxib
Varicella Virus Vaccine
Venlafaxine
Vilazodone
Vismodegib
Vortioxetine
Warfarin
Xipamide

Other InteractionsTOP

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Using medicines in this class with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use your medicine, or give you special instructions about the use of food, alcohol, or tobacco.

Ethanol
Tobacco

PrecautionsTOP

If you will be taking this medicine for a long time, or in high doses, your doctor should check your progress at regular visits. This is especially important for elderly people, who may be more likely than younger adults to develop serious kidney problems if they take large amounts of this medicine for a long time.

Check with your doctor:

If you are taking this medicine to relieve pain and the pain lasts for more than 10 days (5 days for children), if the pain gets worse, if new symptoms occur, or if the painful area is red or swollen. These could be signs of a serious condition that needs treatment.
If you are taking this medicine to bring down a fever, and the fever lasts for more than 3 days or returns, if your fever gets worse, if new symptoms occur, or if redness or swelling is present. These could be signs of a serious condition that needs treatment.
If you are taking this medicine for a sore throat, and the sore throat is very painful, lasts for more than 2 days, or occurs together with or is followed by fever, headache, skin rash, nausea, or vomiting.

Do not take any of the combination medicines containing aspirin for 5 days before any surgery, including dental surgery, unless otherwise directed by your medical doctor or dentist. Taking aspirin during this time may cause bleeding problems.

Check the label of all over-the-counter (OTC), nonprescription, and prescription medicines you now take. If any of them contain acetaminophen, aspirin, other salicylates such as bismuth subsalicylate (e.g., Pepto Bismol) or magnesium salicylate (e.g., Nuprin Backache Caplets), or salicylic acid (present in some shampoos and skin products), check with your health care professional. Using any of them together with this medicine may cause an overdose.

Stomach problems may be more likely to occur if you drink three or more alcoholic beverages while you are taking aspirin. Also, liver damage may be more likely to occur if you drink three or more alcoholic beverages while you are taking acetaminophen.

Taking certain other medicines together with acetaminophen and salicylates may increase the chance of unwanted effects. The risk will depend on how much of each medicine you take every day, and on how long you take the medicines together. If your medical doctor or dentist directs you to take these medicines together on a regular basis, follow his or her directions carefully. However, do not take any of the following medicines together with any of these combination medicines for more than a few days unless your doctor has directed you to do so and is following your progress:

Diclofenac (e.g., Voltaren)
Diflunisal (e.g., Dolobid)
Etodolac (e.g., Lodine)
Fenoprofen (e.g., Nalfon)
Floctafenine (e.g., Idarac)
Flurbiprofen, oral (e.g., Ansaid)
Ibuprofen (e.g., Motrin)
Indomethacin (e.g., Indocin)
Ketoprofen (e.g., Orudis)
Ketorolac (e.g., Toradol)
Meclofenamate (e.g., Meclomen)
Mefenamic acid (e.g., Ponstel)
Nabumetone (e.g., Relafen)
Naproxen (e.g., Naprosyn)
Oxaprozin (e.g., Daypro)
Phenylbutazone (e.g., Butazolidin)
Piroxicam (e.g., Feldene)
Sulindac (e.g., Clinoril)
Tenoxicam (e.g., Mobiflex)
Tiaprofenic acid (e.g., Surgam)
Tolmetin (e.g., Tolectin)

The antacid present in buffered forms of these combination medicines can keep other medicines from working properly. If you need to take a buffered form of this medicine, and you are also taking one of the following medicines, be sure to take the buffered acetaminophen and salicylate combination medicine:

At least 6 hours before or 2 hours after taking ciprofloxacin (e.g., Cipro) or lomefloxacin (e.g., Maxaquin).
At least 8 hours before or 2 hours after taking enoxacin (e.g., Penetrex).
At least 2 hours after taking itraconazole (e.g., Sporanox).
At least 3 hours before or after taking ketoconazole (e.g., Nizoral).
At least 2 hours before or after taking norfloxacin (e.g., Noroxin) or ofloxacin (e.g., Floxin).
At least 3 or 4 hours before or after taking a tetracycline antibiotic by mouth.
At least 1 or 2 hours before or after taking any other medicine by mouth.

If you are taking a laxative containing cellulose, do not take it within 2 hours of taking this medicine. Taking the laxative and this medicine close together may make this medicine less effective by preventing the salicylate in it from being absorbed by your body.

Acetaminophen and salicylate combinations may interfere with the results of some medical tests. Before you have any medical tests, tell the person in charge if you have taken any of these combination medicines within the past 3 or 4 days. If possible, it is best to call the laboratory where the test will be done about 4 days ahead of time to find out whether the medicine may be taken during the 3 or 4 days before the test.

For patients with diabetes:

Acetaminophen and salicylate combinations may cause false results with some blood and urine glucose (sugar) tests. If you notice any change in your test results, or if you have any questions about this possible problem, check with your health care professional. This is especially important if your diabetes is not well-controlled.

For patients taking one of the products that contain caffeine:

Caffeine may interfere with the results of a test that uses adenosine (e.g., Adenocard) or dipyridamole (e.g., Persantine) to help find out how well your blood is flowing through certain blood vessels. Therefore, you should not have any caffeine for 8 to 12 hours before the test.

If you think that you or anyone else may have taken an overdose of this medicine, get emergency help at once. Taking an overdose of a salicylate may cause unconsciousness or death. The first symptom of an aspirin overdose may be ringing or buzzing in the ears. Other signs include convulsions (seizures), hearing loss, confusion, severe drowsiness or tiredness, severe excitement or nervousness, and unusually fast or deep breathing. Signs of severe acetaminophen overdose may not appear until 2 to 4 days after the overdose is taken, but treatment to prevent liver damage or death must be started within 24 hours or less after the overdose is taken.