Leukemia Home > Purinethol Drug Interactions
The following sections explain in detail the potentially negative reactions that can occur when Purinethol is combined with any of the drugs listed above.
5-ASA derivatives may increase the risk for potentially serious Purinethol side effects, especially in people with a certain genetic (inherited) risk factor that causes low levels of an enzyme known as thiopurine methyltransferase (TPMT). Your healthcare provider can check you for a TPMT deficiency, if needed.
Allopurinol reduces the activity of an enzyme that helps to remove Purinethol from the body and, therefore, may increase levels of Purinethol in the body. If you take these medicines together, your healthcare provider will need to reduce your Purinethol dose to one-third to one-quarter of the usual recommended dose to avoid the risk for potentially serious side effects, such as extremely low blood cell counts.
Combining amphotericin B with chemotherapy medicines, such as Purinethol, may increase the risk for amphotericin B side effects, such as kidney damage, low blood pressure (hypotension), and lung problems. Your healthcare provider may choose to monitor you more closely if you take these medicines together.
Azathioprine is converted into mercaptopurine (the active ingredient in Purinethol) in the body. Taking these medicines together may cause high mercaptopurine blood levels, thereby increasing the risk for serious side effects. These medicines should not be used together.
Certain Biologic and Immunologic Medications
Taking Purinethol with other medicines that suppress the immune system, such as certain biologic and immunologic medications, could increase your risk for low blood cell counts, which may cause infections, anemia, and bleeding problems. It is recommended that Purinethol not be used in combination with some biologic and immunologic medicines, while other combinations will require careful monitoring.
Taking clozapine with Purinethol may increase the risk for dangerously low white blood cells and potentially serious infections. Talk to your healthcare provider before taking these medicines together. However, do not stop taking clozapine unless your healthcare provider specifically tells you to do so.
The combination of Purinethol and doxorubicin has been reported to cause liver damage. Your healthcare provider will need to closely monitor your liver function if you take these medicines together.
Purinethol may be less effective if taken with echinacea. Do not take these medications together without your healthcare provider's approval.
Febuxostat reduces the activity of an enzyme that helps to remove Purinethol from the body. Taking these medicines together could cause high blood levels of Purinethol, thereby increasing the risk for potentially serious side effects. These medicines should generally not be used together.
Live vaccines are vaccines that contain live viruses or bacteria. If you receive a live vaccine while taking Purinethol, you might become infected with the virus or bacteria from the vaccine. Also, live vaccines may be less effective in people taking Purinethol.
In general, people going through chemotherapy treatment are advised to not receive a live vaccination. Talk to your healthcare provider before receiving a vaccination or immunization during Purinethol treatment, and for three months after your last dose.
Combining roflumilast with Purinethol may further increase your risk for developing infections. Talk to your healthcare provider about this potential interaction before taking these medicines together.
Purinethol could decrease the effectiveness of sipuleucel-T. This is because sipuleucel-T is thought to work by stimulating the body's immune system, while Purinethol decreases the activity of the immune system. Talk to your healthcare provider about this possible interaction before taking these medicines together.
Sulfamethoxazole and Trimethoprim
Taking Purinethol with sulfamethoxazole and trimethoprim may increase your risk of low white blood cell counts, which can make you more vulnerable to infections. Talk to your healthcare provider before taking these medications together.
Purinethol may decrease the effectiveness of warfarin, possibly increasing your risk for blood clots. If you take these medicines together, your healthcare provider should monitor your prothrombin time ("protime" or PT) and international normalized ratio (INR) more closely than usual, and adjust your warfarin dose if needed.