FDA Issues New Warnings For Muscle Spasm Drug Tizanidine (ZANAFLEX)

The muscle spasm drug tizanidine (ZANAFLEX) combined with certain other drugs Tcould cause serious complications such as drowsiness and can dramatically lower blood pressure, according to the Food and Drug Administration (FDA).   

The FDA announced April 11 that it will require drugmakers to change the professional product label for the drug to warn people about these dangers. (To find the new label, visit www.fda.gov/medwatch/safety/2007/Zanaflex_PI_apr07.pdf.)

The label would now state that when taken in combination with the antidepressant fluvoxamine (LUVOX) or the antibiotic ciprofloxacin (CIPRO), tizanidine can lower blood pressure and sedate some patients. The label also lists certain drugs and families of drugs that should be avoided when taking tizanidine. (These drugs appear in the box below.)

Tizanidine was approved by the FDA in November 1996 for the management of muscle spasms in patients with conditions such as multiple sclerosis and spinal cord injury. It also is available in Japan and Europe as a short-term muscle relaxant.

The drug label includes a warning urging caution when taking this drug in combination with blood pressure-lowering drugs. Even when used alone, patients may experience dizziness, lightheadedness or fainting when getting up suddenly from a sitting or lying position.

What You Can Do
If you are taking tizanidine, you should avoid taking the drugs listed in the table that accompanies this article.