Generic name: Tizanidine.

Zanaflex is a skeletal muscle relaxant. It works by affecting the nerves that control major muscle systems.

Quick Facts About Zanaflex


Used to treat spastic muscle movements usually associated with a nervous system condition.

Zanaflex Dosage

Take exactly as prescribed, with or without food. Do not increase dosage without consulting your doctor.

  • Usual adult dose: 8 milligrams every 6 to 8 hours as needed. Do not exceed 36 milligrams per day.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: usually prescribed on an as-needed basis. If regular treatment is prescribed and dose is missed, take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Zanaflex Side Effects

Overdose symptoms:

very slow breathing. If you suspect an overdose, immediately seek medical attention.

More common side effects: dry mouth, sleepiness, tiredness, weakness.

Less common Zanaflex side effects: constipation, depression, diarrhea, difficulty speaking, double vision, fever, flulike symptoms, hallucinations, liver inflammation, loss of muscular control, nervousness, “pins and needles” in hands and feet, runny nose, skin sores, sore throat, sweating, upset stomach, urinary infection or frequent urinating, vomiting. Rare side effects are associated with virtually every system in the body.


Inform your doctor before combining Zanaflex with:

acetaminophen; blood-pressure-lowering medications; oral contraceptives.

Alcohol may increase sedative effects of Zanaflex; do not drink alcohol while taking this medication.

Special Cautions

Effects of Zanaflex on pregnant women and nursing mothers not known. If pregnant, planning to become pregnant, or breastfeeding, inform your doctor immediately. Take only if absolutely necessary and potential benefits outweigh potential risks.

Seniors should use with caution.

Not generally prescribed for children.

  • Inform your physician before treatment if you have kidney or liver disease. Doctor may decrease dose or recommend not using Zanaflex.
  • May cause low blood pressure, especially in the first 1 to 3 hours after taking dose. Use caution when rising from a sitting or lying position.
  • May cause drowsiness and impair your ability to drive a car or operate machinery. Do not take part in any activity that requires alertness.
  • Hallucinations, delusion, and psychotic symptoms have been reported; be aware of this possibility.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Zanaflex side effects, please contact your healthcare provider