tizanidine (Zanaflex)

Tizanidine is a skeletal muscle relaxant. It works on alpha2 receptors in the central nervous system (brain and spinal cord) and blocks nerve impulses from reaching muscles which produces muscle relaxation. The FDA approved tizanidine in November 1996.

Zanaflex

GENERIC AVAILABLE: Yes

Yes

Tizanidine is used for the treatment and management of skeletal muscle spasticity. Spasticity may be due to multiple sclerosis or spinal cord injury.

Common side effects of tizanidine include:

• low blood pressure,
• dry mouth,
• dizziness,
• sleepiness,
• weakness,
• fatigue,
• blurred vision, and
• constipation.

Initially take 2 - 4 mg by mouth every 6 to 8 hours for up to 3 doses in 24 hours. Increase by 2 to 4 mg until satisfactory response is achieved; however, the maximum dose is 36 mg per day.

Tizanidine should not be used with:

• ciprofloxacin (Cipro),
• amiodarone (Cordarone),
• cimetidine (Tagamet),
• oral contraceptives,
• acyclovir (Zovirax), and
• fluvoxamine (Luvox).

These medications can slow down the breakdown of tizanidine and lead to increased sedation, drowsiness and slowed reflexes.

Tizanidine should be used with caution with medications like:

• alprazolam (Xanax),
• clonazepam (Klonopin),
• diazepam (Valium),
• zolpidem (Ambien),
• oxycodone (Roxicodone),
• hydromorphone (Dilaudid),
• amitriptyline (Elavil),
• nortriptyline (Pamelor) and
• alcohol.

These medications can further increase the side effects of tizanidine.

There are no adequate studies done on tizanidine to determine safe and effective use in pregnant women.

It is not known whether tizanidine enters human milk. Because it is soluble in lipids, it might pass into breast milk.

What preparations of tizanidine-oral are available?

Capsules: 2, 4, 6 mg; Tablets: 2, 4 mg

How should I keep tizanidine-oral stored?

Store tizanidine tablets and capsules between temperatures of 15 C – 30 C (59 F – 86 F).