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Drug Interactions between allopurinol and mercaptopurine

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Major

allopurinol mercaptopurine

Applies to: allopurinol and mercaptopurine

Using allopurinol together with mercaptopurine can increase the effects of mercaptopurine. This can cause fever, chills, sore throat, body aches, weakness, muscle pain, easy bruising or bleeding, mouth sores, pale stools, darkened urine, or severe nausea, vomiting, and diarrhea. If your doctor prescribes these medications together, you may need a dose adjustment or special tests to safely take both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Drug and food interactions

Moderate

allopurinol food

Applies to: allopurinol

Consumer information for this interaction is not currently available.

ADJUST DOSING INTERVAL: The tolerability of allopurinol may be improved by giving it after a meal. Additionally, when the dose is greater than 300 mg, dividing the total daily dose into smaller doses administered more often may be appropriate to help minimize gastrointestinal irritation.

MONITOR: Concomitant use of allopurinol with central nervous system (CNS) depressants, including alcohol, may potentiate adverse effects such as somnolence and sedation.

MANAGEMENT: To improve tolerability, some manufacturers suggest administering allopurinol after a meal. Additionally, if the daily dose is greater than 300 mg, administering allopurinol in divided doses may help reduce gastrointestinal intolerance. Patients should also be counseled to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until they know how the medication affects them.

References

  1. (2024) "Product Information. Allopurinol (Sandoz) (allopurinol)." Sandoz Pty Ltd
  2. (2021) "Product Information. Zyloric (allopurinol)." Aspen Pharma Trading Ltd
  3. (2021) "Product Information. Zyloprim (allopurinol)." AA Pharma Inc, 248178
  4. (2024) "Product Information. Allopurinol (allopurinol)." Actavis U.S. (Purepac Pharmaceutical Company)
View all 4 references
Moderate

mercaptopurine food

Applies to: mercaptopurine

You may experience reduced absorption of mercaptopurine in the presence of food. Take mercaptopurine on an empty stomach 1 hour before or 2 hours after a meal. This will make it easier for your body to absorb the medication.

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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