Tizanidine HCl (Generic Zanaflex) - Uses, Dosage and Side Effects

Tizanidine Hydrochloride is a drug that is used as a muscle relaxant. It is used to treat the spasms, cramping, and tightness of muscles caused by medical problems such as multiple sclerosis, spastic diplegia, back pain, or certain other injuries to the spine or central nervous system. It is also prescribed off-label for migraine headaches, as a sleep aid, and as an anticonvulsant. It is also prescribed for some symptoms of fibromyalgia.
Tizanidine has been found to be as effective as other antispasmodic drugs and have superior tolerability than baclofen and diazepam. Tizanidine may cause hypotension, so caution is advised when it is used in patients who have a history of orthostatic hypotension. Use caution with this drug as it can be very strong even at the 2 mg dose.
Tizanidine can occasionally cause liver damage, generally the hepatocellular type. Clinical trials show that up to 5% of patients treated with tizanidine had elevated liver function test values, though symptoms disappeared upon withdrawal of the drug. Care should be used when first beginning treatment with tizanidine with regular liver tests for the first 6 months of treatment.

Tizanidine Hydrochloride (Generic Zanaflex) - Availability And Packaging

Tizanidine Hydrochloride is available under the brand names Zanaflex Tablets and Sirdalud Tablets which is packaged 2 and 4 mg tablets for oral administration. Tizanidine is also supplied in gel cap form in doses of 2 mg, 4 mg, and 6 mg. The tablets are composed of the active ingredient, tizanidine hydrochloride (2.288 mg equivalent to 2 mg tizanidine base and 4.576 mg equivalent to 4 mg tizanidine base), and the inactive ingredients, silicon dioxide colloidal, stearic acid, microcrystalline cellulose and anhydrous lactose.

Side Effects of Tizanidine HCl (Generic Zanaflex)

Tizanidine Hydrochloride can possibly cause the following side effects: Drowsiness, dry mouth with increased dosage, dizziness.

Tizanidine Hydrochloride - Dosage

It is recommended to begin treatment with single oral doses of 4 mg and increase the dose gradually (2 to 4 mg steps) to optimum effect (satisfactory reduction of muscle tone at a tolerated dose).

Tizanidine Hydrochloride - Interactions

Concomitant use of tizanidine and moderate or potent CYP1A2 inhibitors is contraindicated. Concomitant use of tizanidine with fluvoxamine, a potent CYP1A2 inhibitor in man, resulted in a 33-fold increase in the tizanidine AUC (plasma drug concentration-time curve) by fluvoxamine. Tizanidine is a potent sedative. It therefore has the potential, to interact with other CNS depressants. Alcohol should obviously be avoided, particularly as it can cause stomach upset.

Additional Information

Additional Info: Prescribing Information

Considerable portions of the text here is from http://en.wikipedia.org/wiki/Tizanidine and is reproduced here under the Creative Commons Attribution-ShareAlike License