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What is Zanaflex?

Zanaflex is a brand-name used by Acorda Therapeutics for tizanidine, a short-acting muscle relaxant used to treat spasticity, cramping back pain and muscle tension caused by various medical conditions including multiple sclerosis and spinal cord injuries. It is most commonly used to permit patients to undertake daily activities by controlling spasms. It may also be used as symptomatic relief for some symptoms of fibromyalgia.

Zanaflex is an alpha-2 adrenergic agonist. By binding to and stimulating alpha-2 receptors, it inhibits the activity of motor neurons. This inhibition takes place in the central nervous system, not within muscles.

What does Zanaflex look like?

Zanaflex is available in various presentations in tablets or capsules of 2 and 4 mg and capsules of 6 mg strength.

Zanaflex dosing and administration

The standard initial dose of Zanaflex as an antispasmodic is 4 mg up to three times per day as needed. If this dosage is ineffective your doctor may increase it incrementally until the desired effect is achieved. The forms of Zanaflex in tablets and capsules are not the same and are metabolized differently. Therefore the effective dose of each may be different and they should not be substituted for each other without consulting your doctor. The peak concentration of Zanaflex is reached about one or two hours after ingestion and the period of effectiveness is between three and six hours. It is important to plan ahead when using it to facilitate the performance of activities. Taking Zanaflex capsules with food reduces the effective peak level, however taking the tablet form with food potentiates the peak.

Adverse effects from Zanaflex

Zanaflex has a number of rare but extremely serious side effects and you should consult your doctor if any of the following symptoms occur: jaundice, dark urine or pain in the upper right abdomen, very low blood pressure, very slow heart rate, arrhythmia, allergic reaction, hallucinations, paranoia or delusions. There are a number of less serious but very common reactions including drowsiness, dry mouth, fatigue, vertigo, hypotension, slow hear rate or urinary tract infection. Other mild and less common reactions include constipation, vomiting slurred speech, blurred vision, frequent urination, fever, chills, sore throat, nasal congestion, nervousness and muscle twitching.

Zanaflex warnings and precautions

Zanaflex may occasionally cause hepatocellular damage. In clinical trials, 5% of patients taking tizanidine had elevated liver function. This effect is reversible on discontinuation of treatment. Liver function should be monitored carefully during the first six months of treatment. If you have any recent history of liver disease you should discuss this with your doctor before taking Zanaflex.

Interactions with Zanaflex

Zanaflex may interact with fluvoxamine. Because of its powerful sedative effect, Zanaflex should not be taken in combination with other central nervous system depressants, including alcohol. Because Zanaflex may lower blood pressure it should be taken with caution when in combination with medications for high blood pressure.