Can I take Sertraline and Tizanidine together?

You should only take sertraline and tizanidine together if your doctor has specifically told you it’s okay to do so.

Combining them can cause your blood pressure to drop too low and increases the risk of drowsiness and dizziness.

Taking them together can also increase the risk of serotonin syndrome.

Why this happens

Both drugs can lower blood pressure and cause drowsiness (additive effect). Additionally, sertraline can slightly interfere with how the liver breaks down tizanidine, and both drugs influence serotonin levels in the brain.

How to know if you're experiencing a drug interaction

You may be experiencing an interaction between sertraline and tizanidine if:

• You feel drowsy or dizzy.

• Feel like you might faint or do faint.

• Feel unusually sleepy.

• Have very low blood pressure.

• Feel confused or have difficulty concentrating.

How to take sertraline and tizanidine safely

• Speak to your doctor before taking these together.

• If you are already taking both, do not stop taking them suddenly.

• Watch out for extreme dizziness, fainting, confusion, or shivering. Your doctor may need to adjust your dose.

Important precautions

Depression and anxiety disorders

You may experience an increase in suicidal thoughts or the urge to self-harm when first starting sertraline or changing the dose. This is more common in young adults under 25. Contact your doctor or go to hospital immediately if you notice any changes in your mood or behaviour.

Serotonin Syndrome

Taking these medicines together increases the risk of serotonin syndrome, a potentially life-threatening condition. Seek urgent medical care if you experience agitation, hallucinations, fast heartbeat, or severe muscle stiffness.

Bleeding disorders

Sertraline can increase your risk of bleeding, particularly from the stomach. Use with caution if you take blood-thinning medicines (like warfarin) or anti-inflammatory painkillers (like ibuprofen or aspirin), as this significantly increases the risk of serious bleeding.

Low blood pressure (Hypotension)

Tizanidine can cause a significant drop in blood pressure, leading to dizziness or fainting, especially when moving from sitting to standing. This risk is much higher if taken with certain blood pressure medicines or ciprofloxacin.

Liver problems

Tizanidine can cause serious liver damage. You will need regular blood tests to check your liver function while taking this medicine.

Stopping treatment suddenly

Do not stop taking tizanidine suddenly. Doing so can cause a rapid increase in heart rate and dangerously high blood pressure. Your dose must be reduced gradually.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking these medicines. Combining alcohol with sertraline or tizanidine can significantly increase drowsiness, dizziness, and the risk of falls. It may also impair your coordination and judgement.

Grapefruit juice

You should avoid drinking large amounts of grapefruit juice while taking sertraline. Grapefruit can increase the level of sertraline in your blood, which may increase the risk of side effects.

Caffeine (Coffee, Tea, Energy Drinks)

You should avoid or strictly limit caffeine intake. Caffeine can significantly increase the levels of tizanidine in your body, which can lead to severe side effects such as very low blood pressure, a slow heart rate, or extreme drowsiness.

Food (General)

You should choose to take tizanidine either always with food or always without food. Switching between the two can change how much medicine your body absorbs, which may make the medicine less effective or increase side effects.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.