Can I take Losartan and Tizanidine together?

Why this happens

Both medicines have the effect of lowering blood pressure, though they do it in different ways. Losartan is specifically for blood pressure, while tizanidine is a muscle relaxant that also has a strong blood-pressure-lowering effect. When used together, their effects add up (an additive effect), which can lead to an excessive drop in blood pressure.

You should use this combination with caution. When you first start taking them together, or if your dose is increased, be careful when standing up. Move slowly to give your body time to adjust. If you feel very dizzy, faint, or unusually sleepy, contact your doctor. They may need to adjust your doses or monitor your blood pressure more closely.

Low blood pressure (Hypotension)

Both medicines lower blood pressure. Taking them together significantly increases the risk of severe dizziness, fainting, or a sudden drop in blood pressure when standing up.

Pregnancy

You must not take losartan if you are pregnant. It can cause serious harm or death to an unborn baby, especially if taken during the second and third trimesters.

Liver problems

Tizanidine can cause serious liver damage. You will need regular blood tests to check your liver function, and you must report any yellowing of the skin or eyes (jaundice) or severe nausea immediately.

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.

Alcohol

It is best to avoid or strictly limit alcohol while taking losartan. Alcohol can increase the blood pressure-lowering effect of losartan, which may make you feel dizzy, lightheaded, or faint, especially when standing up. Combining alcohol with medication also increases the risk of liver damage.

It is best to avoid or strictly limit alcohol while taking tizanidine. Alcohol can significantly increase the sedative effects of this medicine, making you feel extremely drowsy or dizzy, and increases the risk of accidental injury.

Potassium-rich foods (e.g., bananas, spinach, salt substitutes)

Losartan can increase the levels of potassium in your blood. You should avoid using salt substitutes containing potassium (such as Lo-Salt) and speak to your doctor before significantly increasing your intake of potassium-rich foods, as high potassium levels can affect your heart rhythm.

Caffeine (e.g. coffee, tea, energy drinks, cola)

Caffeine can interfere with how your body breaks down tizanidine, leading to higher levels of the medicine in your blood. This can increase the risk of side effects like extreme drowsiness, dry mouth, and low blood pressure. Try to limit your caffeine intake while taking this medicine.

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.