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:
Fluvoxamine may slow down how quickly your liver processes tizanidine.
What might happen:
The amount of tizanidine in your blood may increase and cause more side effects than normal, including severe low blood pressure and drowsiness.
What you should do about this interaction:
Contact your healthcare professional (e.g. doctor or pharmacist) right away about using these medicines together.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.
1.Luvox (fluvoxamine maleate) US prescribing information. ANI Pharmaceuticals November, 2012.
2.Zanaflex (tizanidine hydrochloride) US prescribing information. Acordia Therapeutics, Inc. July, 2006.
3.Granfors MT, Backman JT, Neuvonen M, Ahonen J, Neuvonen PJ. Fluvoxamine drastically increases concentrations and effects of tizanidine: a potentially hazardous interaction. Clin Pharmacol Ther 2004 Apr; 75(4):331-41.
4.Granfors MT, Backman JT, Laitila J, Neuvonen PJ. Tizanidine is mainly metabolized by cytochrome p450 1A2 in vitro. Br J Clin Pharmacol 2004 Mar; 57(3):349-53.
5.Momo K, Doki K, Hosono H, Homma M, Kohda Y. Drug interaction of tizanidine and fluvoxamine. Clin Pharmacol Ther 2004 Nov;76(5):509-10.
6.Phansalkar S, Desai AA, Bell D, Yoshida E, Doole J, Czochanski M, Middleton B, Bates DW. High-priority drug-drug interactions for use in electronic health records. J Am Med Inform Assoc 2012 Sep-Oct; 19(5):735-43.