Tizanidine Side Effects: What to Expect and When to Worry
Tizanidine is a muscle relaxant often prescribed for spasticity. It can help with tight, painful muscles, but it also comes with side effects you should know about. Below I’ll lay out the common effects, the more serious risks, key drug interactions, and practical tips so you can use it safely.
Common and expected side effects
The things people notice most are drowsiness, dizziness, dry mouth, and weakness. Many patients feel sleepy or clumsy at first — that’s the drug slowing the nervous system. Other common complaints are fatigue, low blood pressure (feeling lightheaded when standing), and slowed heartbeat. These are usually dose-related: higher doses mean more symptoms.
If you drive or operate machines, wait until you know how tizanidine affects you. Drinking alcohol or taking other sedatives (like benzodiazepines, opioids, or some sleep meds) can make sleepiness and breathing suppression worse.
Serious risks and red flags
Some side effects need urgent attention. Severe low blood pressure or fainting, chest pain, sudden fast heartbeat, or signs of liver injury (yellowing skin/eyes, dark urine, persistent nausea or stomach pain) require immediate medical care. Tizanidine can raise liver enzymes in some people, so doctors often check liver tests before and during treatment.
Stopping tizanidine suddenly can cause rebound high blood pressure, fast heart rate, and increased spasticity. If you need to stop, your doctor will usually taper the dose slowly rather than cut it off at once.
Certain psychiatric effects — confusion, hallucinations, severe mood changes — are rare but reported. If you or someone close notices unusual thinking or behavior, call your clinician.
Drug interactions matter more with tizanidine than with many other meds. Strong CYP1A2 inhibitors like ciprofloxacin or fluvoxamine can raise tizanidine levels a lot, causing extreme drowsiness and low blood pressure. Combining tizanidine with antihypertensives, other muscle relaxants, or strong sedatives increases risk too. Always tell your prescriber about every medicine and supplement you take.
Pregnancy and breastfeeding: doctors weigh benefits vs risks. Tizanidine isn’t a first choice in pregnancy; discuss options with your clinician. Elderly people often feel more sedated and are at higher fall risk, so prescribers usually start low and go slow.
Practical tips: take it exactly as prescribed, don’t mix with alcohol, avoid abrupt stopping, and report dizziness, fainting, or yellowing skin right away. Keep follow-up visits for blood pressure checks and liver tests when recommended. If you suspect a severe reaction, seek emergency care.
Questions for your doctor: Could my other meds interact with tizanidine? How quickly should I taper if I stop? When should I get liver tests? A short chat with your prescriber or pharmacist can prevent most problems and keep treatment useful and safe.
