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:
The cause of this interaction is not known. 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. They 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.
1.Zagam (sparfloxacin) US prescribing information. Bertek Pharmaceuticals, Inc. February, 2003.
2.Raxar (grepafloxacin) US prescribing information. Glaxo Wellcome, Inc. November, 1997.