Recommended starting dose: 2 mg; dose can be repeated at 6 to 8 hour intervals, up to a maximum of 3 doses in 24 hours Dosage can be increased by 2 mg to 4 mg per dose, with 1 to 4 days between increases; total daily dose should not exceed 36 mg Tizanidine pharmacokinetics differs between tablets and capsules, and when taken with or without food. These differences could result in a change in tolerability and control of symptoms To discontinue Zanaflex, decrease dose slowly to minimize the risk of withdrawal and rebound hypertension, tachycardia, and hypertonia

Male Wi star rats (300-350g) were decapitated and the kidneys were rapidly removed. The kidneys were minced in ice-cold 50 mM Tris-HCI, 5 mM EDTA (pH 7.7) and then homogenized by a polytron. The homogenate was filtered through 4 layers of silk gauze. and centrifuged at 40,000 X g for 13 min. The pellet was resuspended in 50 mM Tris-HCI, 25 mM NaCI buffer (pH 7.7), incubated for 30 min at 25°C, and recen trifuged as described above. The final pellet was resuspended in 50 mM Tris-HC1 buffer (pH 7.7) and used for the binding assay. Incubations were performed in duplicate at 25°C for 40 min in a total volume of 1 ml. The incubate consisted of 3H p-aminoclonidine (3H-PAC), a suspension of kidney membranes (approximately 0.55 mg/ml) and either buffer alone or buffer containing Tizanidine. Non-specific binding was defined by parallel incubations containing 10,uM phentolamine. In experiments using adrenaline, all samples contained ascortic acid in a final concentration of 0.01%. Incubations were terminated by vacuum filtration over Whatman GF/C filters by using a cell harvester. The filters were washed with ice-cold Tris-HCI; then the filter-bound radioactivity was determined using a scintillation counter (Aloka, Japan).