Serious. These medicines may interact and cause very harmful effects. 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 process mefloquine, quinidine, or quinine more quickly.
What might happen:
Your blood levels of quinidine may decrease and cause a fast or irregular heartbeat.Mefloquine and quinine may not work as well for treating malaria.
What you should do about this interaction:
Make sure your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. If you are taking quinidine, let your doctor know if you experience a fast or irregular heartbeat. It may be necessary to measure your blood levels of quinidine more often. Your doctor may need to adjust the dose. Medicines used to treat seizures and other conditions may make this interaction worse.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
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