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, a harmful effect on your heart may result.
What might happen:
You may experience an irregular heartbeat that may be life threatening.
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 or if you have taken mefloquine in the previous 15 weeks. They may already be aware of this drug interaction and may be monitoring you for it. If you have or have had an irregular heartbeat, your chances for experiencing this effect are increased. Do not start, stop, or change the dosage of any medicine before checking with them first.
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