Can I take Metformin and Tramadol together?

Why this happens

Tramadol may increase the body's sensitivity to insulin or stimulate insulin release, which lowers blood sugar. When combined with metformin, this effect is enhanced. Both drugs also have a very small risk of causing a build-up of lactic acid in the blood, particularly in patients with reduced kidney function.

What you should do

You should use this combination with caution. Monitor your blood sugar levels more frequently than usual, especially when starting tramadol or changing the dose. Learn to recognise the signs of low blood sugar (such as shaking, sweating, hunger, or dizziness) and keep a fast-acting sugar source nearby. If you feel generally unwell, very tired, or have unusual muscle pain, contact your doctor immediately. It is also best to avoid or strictly limit alcohol, as it can further increase the risk of both low blood sugar and lactic acidosis.

Important precautions

Lactic acidosis

Metformin can cause a rare but serious build-up of acid in the blood. Seek urgent medical help if you experience extreme tiredness, muscle pain, or difficulty breathing. This risk is higher if you have severe kidney problems or drink excessive alcohol.

Epilepsy or history of seizures

Tramadol can increase the risk of having a fit (seizure), especially if you are already prone to them or are taking other medicines that lower the seizure threshold.

Asthma or breathing difficulties

Tramadol can slow down your breathing. You should not take it if you have severe asthma or significant breathing problems, as it can lead to dangerous respiratory depression.

Severe dehydration or infection

If you develop severe vomiting, diarrhoea, or a high fever, you must temporarily stop taking metformin and contact your doctor to prevent kidney strain.

Serotonin Syndrome risk

Tramadol can cause a life-threatening reaction called serotonin syndrome if taken with certain antidepressants. Seek urgent medical help if you experience high fever, agitation, or muscle twitching.

Medical scans using iodine contrast dye

If you are having an X-ray or scan involving an injection of iodine contrast dye, you must stop taking metformin before or at the time of the test to prevent sudden kidney failure.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol when taking tramadol. Combining alcohol with tramadol significantly increases the risk of dangerous side effects, such as extreme sleepiness, breathing difficulties, and loss of consciousness. In severe cases, this combination can be fatal.

It is best to avoid or strictly limit alcohol while taking metformin. Drinking alcohol with this medicine increases the risk of a rare but serious condition called lactic acidosis (a build-up of lactic acid in the blood). It also increases the risk of low blood sugar (hypoglycaemia).

Vitamin B12 absorption

Long-term use of metformin can prevent your body from absorbing enough vitamin B12 from your food. You may need to have your B12 levels checked by your doctor or take a supplement if you develop symptoms like extreme tiredness or a sore tongue.

General Food Advice

Metformin should be taken with or just after a meal or snack. This helps to reduce the risk of common side effects such as stomach upset, indigestion, or nausea.

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.