Indications
Tizanidine is a muscle relaxant used to reduce spasticity (muscle stiffness and tightness) caused by conditions such as multiple sclerosis, spinal cord injury or stroke. It is also used for short periods to relieve painful muscle spasm, for example with back or neck pain.
How It Works
Tizanidine acts on alpha-2 receptors in the brain and spinal cord. It reduces the nerve signals that make muscles contract too much, so muscles relax and move more freely. It does not act directly on the muscles themselves.
Dosage and Administration
For painful muscle spasm in adults, the usual dose is 2 mg to 4 mg up to three times a day. For spasticity the doctor starts with a low dose (often 2 mg) and increases it slowly; take it exactly as prescribed. Take it the same way each time, either always with food or always without, because food changes how much is absorbed. Do not stop suddenly after long or high-dose use, as blood pressure and heart rate can rise; the dose should be reduced gradually.
Interactions
- Never take with Fluvoxamine or Ciprofloxacin: they greatly raise Tizanidine levels and can cause dangerously low blood pressure.
- Other medicines such as Amiodarone, Cimetidine, oral contraceptives, Verapamil and some antibiotics also raise its level.
- Blood pressure medicines can add to its lowering effect.
- Alcohol, sleeping pills, Opioids and sedating antihistamines increase drowsiness.
Contraindications
- Allergy to Tizanidine.
- Severe liver impairment.
- Use with Fluvoxamine or Ciprofloxacin.
Side Effects
Common side effects include drowsiness, tiredness, dizziness, dry mouth, low blood pressure (feeling faint on standing), nausea, muscle weakness and slow heartbeat.
Get urgent medical help if you faint, have a very slow heartbeat, yellow skin or eyes, dark urine or severe tiredness (possible liver injury), hallucinations or confusion, or a severe allergic reaction.
Pregnancy and Lactation
Not recommended in pregnancy unless your doctor decides the benefit outweighs the risk. It may pass into breast milk; avoid breastfeeding unless your doctor advises otherwise.
Precautions and Warnings
- Liver tests may be checked, especially at higher doses.
- Use with care in kidney disease, heart disease and in older people.
- It can cause drowsiness and dizziness; do not drive or operate machinery if affected.
- Stand up slowly to avoid fainting.
Overdose
Overdose can cause severe drowsiness, very low blood pressure, slow heartbeat, breathing problems, confusion and coma. Seek emergency medical help immediately.
Therapeutic Class
Centrally acting skeletal muscle relaxant, alpha-2 adrenergic agonist.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.