Zanaflex (Tizanidine)
What is Zanaflex
Zanaflex, known generically as Tizanidine, is a muscle relaxant used to treat muscle spasticity caused by conditions such as multiple sclerosis, spinal cord injuries, or other neurological disorders. It works by blocking nerve impulses sent to the brain that trigger muscle tightening, helping to relax stiff muscles and improve mobility.
Unlike painkillers, Zanaflex does not treat pain directly but reduces the muscle spasms that often cause discomfort. It is usually prescribed in tablet or capsule form and is taken by mouth, typically every 6–8 hours as needed.
Recommendations
Zanaflex is recommended for the following health conditions:
• Muscle spasticity related to multiple sclerosis;
• Spinal cord injuries;
• Other neurological conditions that cause involuntary muscle stiffness or spasms.
The usual starting dose for adults is 2 mg every 6–8 hours, which may be gradually increased depending on tolerance and response. The maximum daily dose should not exceed 36 mg. Because Zanaflex works quickly and wears off within hours, it is often used for short-term relief rather than continuous daily therapy.
Precautions and Contraindications
Zanaflex may not be suitable for everyone. It should be avoided or used with caution in patients with:
• Allergy to tizanidine;
• Severe liver disease;
• Low blood pressure (hypotension), as the drug can lower blood pressure further;
• Kidney disease, since the drug is cleared through the kidneys;
• A history of hallucinations or mental health issues, as rare psychiatric effects may occur.
Sudden discontinuation after long-term use can cause withdrawal symptoms such as high blood pressure, rapid heart rate, and muscle spasms, so it should be stopped gradually under medical supervision.
Interactions
Zanaflex can interact with several medications, leading to potentially dangerous effects. Key interactions include:
• CYP1A2 inhibitors (ciprofloxacin, fluvoxamine) can dangerously increase tizanidine levels;
• Other muscle relaxants add to additive sedation or weakness;
• Alcohol and sedatives (benzodiazepines, opioids) are associated with increased risk of drowsiness and impaired coordination;
• Blood pressure medications may cause excessive hypotension;
• Oral contraceptives can increase tizanidine concentrations in the blood.
Patients should avoid alcohol and inform their doctor of all current medications to prevent harmful interactions.
Side Effects
Like all drugs out there, Zanaflex may cause side effects if misused, which can range from mild to severe. Among the most common side effects are the following:
• Drowsiness or sleepiness;
• Dizziness or lightheadedness;
• Dry mouth;
• Weakness;
• Fatigue.
Less common but serious side effects may include:
• Severe low blood pressure leading to fainting;
• Liver problems (yellowing of skin or eyes, dark urine);
• Hallucinations or mood changes;
• Irregular heartbeat;
• Allergic reactions (rash, swelling, difficulty breathing).
If serious symptoms develop, immediate medical attention is required.
Overdose
An overdose of Zanaflex can be very dangerous. Symptoms may include:
• Severe drowsiness or confusion;
• Extremely low blood pressure;
• Slow or irregular heartbeat;
• Breathing difficulties;
• Loss of consciousness.
In the event of overdose, emergency medical treatment is necessary. Care may include activated charcoal, intravenous fluids, and monitoring of heart and respiratory function until the patient stabilizes.