Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may not process thiopurines properly.
What might happen:
The blood levels of your thiopurine may increase and cause toxic effects such as fever, chills, easy bruising or bleeding, black or tarry stools, blood in urine, or mouth or lip sores.
What you should do about this interaction:
Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about taking these two medicines together. They may already be aware of this drug interaction and may be monitoring you for it. If you develop any of the symptoms above, contact your doctor. It may be necessary to adjust the dose of your medicine. Do not start, stop, or change the dosage of any medicine before checking with them first.
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