Iso-Acetazone Side Effects
Generic name: acetaminophen / dichloralphenazone / isometheptene mucate
Medically reviewed by Drugs.com. Last updated on Jan 29, 2022.
Note: This document contains side effect information about acetaminophen / dichloralphenazone / isometheptene mucate. Some of the dosage forms listed on this page may not apply to the brand name Iso-Acetazone.
For the Consumer
Applies to acetaminophen/dichloralphenazone/isometheptene mucate: oral capsule
- This drug has acetaminophen in it. Liver problems have happened with the use of acetaminophen. Sometimes, this has led to a liver transplant or death. Most of the time, liver problems happened in people taking more than 4,000 mg (milligrams) of acetaminophen in a day. People were also often taking more than 1 drug that had acetaminophen.
- Avoid drinking alcohol while taking this drug.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
- Not able to pass urine or change in how much urine is passed.
- A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.
What are some other side effects of this drug?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Feeling sleepy.
- Upset stomach.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to acetaminophen / dichloralphenazone / isometheptene mucate: oral capsule
Hypersensitivity side effects including transient dizziness and skin rash have been reported with the use of acetaminophen/dichloralphenazone/isometheptene. Hypersensitivity reactions, including anaphylaxis and fixed drug eruptions have been reported rarely in association with acetaminophen use.[Ref]
Alcoholic patients may develop hepatotoxicity after even modest doses of acetaminophen. In healthy patients, approximately 15 grams of acetaminophen is necessary to deplete liver glutathione stores by 70% in a 70 kg person. However, hepatotoxicity has been reported following smaller doses. Glutathione concentrations may be repleted by the antidote N-acetylcysteine. One case report has suggested that hypothermia may also be beneficial in decreasing liver damage during overdose.
In a recent retrospective study of 306 patients admitted for acetaminophen overdose, 6.9% had severe liver injury but all recovered. None of the 306 patients died.
One study has suggested that acetaminophen may precipitate acute biliary pain and cholestasis. The mechanism of this effect may be related to inhibition of prostaglandin and alterations in the regulation of the sphincter of Oddi.
Hepatic side effects including severe and sometimes fatal dose dependent hepatitis have been reported with the use of acetaminophen in alcoholic patients. Hepatotoxicity has been increased during fasting.[Ref]
Gastrointestinal side effects have been rare with the use of acetaminophen except in alcoholics and after overdose.[Ref]
Acute tubular necrosis with acetaminophen use usually occurs in conjunction with liver failure, but has been observed as an isolated finding in rare cases. A possible increase in the risk of renal cell carcinoma has been associated with chronic acetaminophen use as well.
A recent case-control study of patients with end-stage renal disease suggested that long term consumption of acetaminophen may significantly increase the risk of end-stage renal disease particularly in patients taking more than two pills per day.[Ref]
Renal side effects including acute tubular necrosis and interstitial nephritis have been rare with the use of acetaminophen. Adverse renal effects have been most often observed after overdose, after chronic abuse (often with multiple analgesics), or in association with acetaminophen-related hepatotoxicity.[Ref]
Hematologic side effects including rare cases of thrombocytopenia associated with acetaminophen have been reported. Methemoglobinemia with resulting cyanosis has also been observed in the setting of acute overdose.[Ref]
Dermatologic side effects including erythematous skin rashes associated with acetaminophen have been reported rarely. Acetaminophen associated bullous erythema and purpura fulminans have also been reported.[Ref]
Two cases hypotension have been reported following the administration of acetaminophen. Both patients experienced significant decreases in blood pressure. One of the two patients required pressor agents to maintain adequate mean arterial pressures. Neither episode was associated with symptoms of anaphylaxis. Neither patient was rechallenged after resolution of the initial episode.[Ref]
More about Iso-Acetazone (acetaminophen / dichloralphenazone / isometheptene mucate)
Related treatment guides
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Some side effects may not be reported. You may report them to the FDA.