Informational only — Not medical advice. Always consult a licensed healthcare provider.

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Community data Updated 23 hours ago
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Indications

Tizanidine Hydrochloride is used to treat painful muscle spasms. This includes spasms linked with static and functional disorders of the spine (cervical and lumbar syndromes), and spasms after surgery, for example for a herniated intervertebral disc or osteoarthritis of the hip. Tizanidine Hydrochloride is also used to treat spasticity caused by neurological disorders. These are multiple sclerosis, chronic myelopathy, degenerative spinal cord diseases, cerebrovascular accidents and cerebral palsy.

⚠️ Always consult a registered physician before taking any medicine.

Pharmacology

Tizanidine is a centrally acting skeletal muscle relaxant. It works mainly in the spinal cord. The evidence suggests that it stimulates presynaptic alpha2 receptors, and this stops the release of excitatory amino acids that would otherwise stimulate N-methyl-D aspartate (NMDA) receptors. Polysynaptic signal transmission at the spinal interneuron level is responsible for excessive muscle tone, so blocking it brings the muscle tone down. Besides relaxing muscle, the medicine also has a moderate central analgesic effect.

In terms of its pharmacodynamic action, tizanidine is effective in both acute painful muscle spasms and chronic spasticity of spinal and cerebral origin. It reduces resistance to passive movements, eases spasms and clonus, and may improve voluntary strength. The antispastic activity (measured by the Ashworth score and pendulum test) and the adverse effects (heart rate and blood pressure) are both related to plasma tizanidine concentrations.

Pregnancy & Breastfeeding

There isn't much experience with Tizanidine in pregnant women, so it should not be used during pregnancy unless the benefit clearly outweighs the risk.

Animal data: Reproduction studies in rats and rabbits did not show evidence of teratogenicity. In rats, dose levels of 10 and 30 mg/kg/day increased the length of gestation. Pup loss went up before and after birth, and development was retarded. At these doses, the dams showed marked signs of muscle relaxation and sedation. Based on body surface area, these doses were 2.2 and 6.7 times the maximum recommended human dose of 0.72 mg/kg/day.

Lactation: Small amounts of tizanidine pass into rat milk. No human data are available, so Tizanidine should not be given to women who are breast-feeding.

Females and males of reproductive potential:

Pregnancy testing: Sexually-active females of reproductive potential are recommended to have a pregnancy test before starting treatment with Tizanidine.

Contraception: Females of reproductive potential should be told that animal studies have shown Tizanidine to be harmful to the developing fetus. Sexually-active females of reproductive potential are recommended to use effective contraception (methods that result in less than 1 % pregnancy rates) during treatment with Tizanidine and for 1 day after stopping it.

Fertility: Animal data: No impairment of fertility was seen in male rats at a dose of 10 mg/kg/day, or in female rats at a dose of 3 mg/kg/day. Fertility was reduced in male rats receiving 30 mg/kg/day and in female rats receiving 10 mg/kg/day. Based on body surface area, these doses were 6.7 and 2.2 times the maximum recommended human dose of 0.72 mg/kg. At these doses, maternal behavioral effects and clinical signs were seen, including marked sedation, weight loss and ataxia.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Dosage Reference

⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.

Adults: Tizanidine has a narrow therapeutic index, and tizanidine plasma concentrations vary a lot from one patient to another, so the dose has to be adjusted for each person. Starting low, at 2 mg three times daily, can reduce the risk of adverse effects. The dose should then be raised carefully, according to what the individual patient needs. Relief of painful muscle spasms: The usual dose is 2 to 4 mg three times daily, in tablet form. In severe cases, an extra dose of 2 or 4 mg may be taken, preferably at night to keep sedation down. Spasticity due to neurological disorders: The starting daily dose should not go above 6 mg, given in 3 divided doses. It can be increased step by step at half-weekly or weekly intervals, by 2 to 4 mg each time. The best response is generally reached with a daily dose of between 12 and 24 mg, given in 3 or 4 equally spaced doses. The daily dose of 36 mg should not be exceeded. Pediatrics patients: Experience in patients below 18 years of age is limited, so Tizanidine is not recommended for this group. Geriatric patients (65 years of age or older): Experience with Tizanidine in the elderly is limited. Because of this, treatment should begin at the lowest dose, and any increase should be made in small steps, depending on how well the patient tolerates it and how well it works. Renal impairment: In patients with renal impairment (creatinine clearance <25 mL/min), treatment should start at 2 mg once daily. Increase the dose in small steps, according to tolerability and efficacy. If the effect needs to be improved, it is advisable to first increase the strength of the daily dose before increasing the frequency of administration. Hepatic impairment: Tizanidine is contraindicated in patients with severe hepatic impairment. It is extensively metabolized in the liver, but limited data are available for this group. Its use has been linked to a reversible abnormality in liver function tests. In moderate hepatic impairment, Tizanidine should be used with caution and treatment should start at the lowest dose. After that, any increase should be made carefully, according to how well the patient tolerates it. Discontinuation of treatment: If Tizanidine has to be stopped, the dose should be brought down slowly, particularly in patients who have taken high doses for a longer period. This helps avoid or reduce the risk of rebound hypertension and tachycardia.

Side Effects & Interactions

Side Effects

No side-effect data recorded yet.