Tylenol Drug Interactions

by on June 28, 2012

Tylenol is a brand medicine containing acetaminophen. It is used for the treatment of pain and fever.  Acetaminophen overdosing is one of the most common causes of acute liver failure. Adult doses higher than 4000 mg can cause liver damaging. It is recommended never to use two different products containing acetaminophen because of the risk of overdosing.

In fact, acetaminophen is a part of a great number of formulations for treating pain, cold symptoms and flu. Always read the labels of these products before using them. Consider the fact that acetaminophen is also called paracetamol in a lot of countries.

Caffeine can increase the pain-killing effect of Tylenol. However, combining high doses of caffeine and Tylenol is also associated with increased risk of liver damaging.

Inform your doctor if you are taking any of these medications:

  • Blood thinners such as Warfarin (Coumadin). Acetaminophen can increase their effects so dose adjustment may be needed during the treatment as well as regular laboratory tests.
  • Metoclopramide (Reglan, Degan) or Domperidone (Mottilium). These are drugs used to treat nausea and vomiting. They can increase the absorption of acetaminophen so dose adjustment may be necessary.
  • Chloramphenicol (Chloromycetin) – antibiotic. There are studies showing that this combination can lead to increased blood concentration of acetaminophen and decreased metabolism of chloramphenicol.
  • Isoniazid– a medicine used to treat tuberculosis. There is an increased risk of liver damaging.
  • Rifampicin – it may decrease the effect of acetaminophen.
  • Probenecid – a medicine used for the treatment of gout. It decreases the urinary excretion of acetaminophen.
  • Barbiturates (Luminal, Seconal, Amytal) and carbamazepine (Tegretol) can decrease the effect of acetaminophen and increase the risk of liver damaging at the same time.

Avoid the use of sedatives and other pain-killers unless you have consulted your doctor.

Some of the Tylenol products are combined and contain dextromethorphan, guaifenesin, phenylephrine, doxylamine succinate or chlorpheniramine. In addition to the above drug interactions, you should also not use sedatives or any central nervous system acting medicines with them . You should not take these products if you have been using MAO inhibitors (antidepressants) in the previous 2 weeks.

Some of the Tylenol products contain acetaminophen and diphenhydramine hydrochloride. Do not combine them with all of the above medicines as well as with antiarythmics.

If you are not sure about the active ingredients of any medicines, consult your doctor.

This list is not complete and other drugs can also interact with Tylenol. Inform your doctor if you are taking any over-the-counter or prescription medicines, herbs or dietary supplements before starting treatment with Tylenol.