Can I take Lansoprazole and Metformin together?

Why this happens

Lansoprazole may slightly interfere with how metformin is cleared from the body by the kidneys. Furthermore, both drugs can reduce the absorption of Vitamin B12 from your diet through different methods in the digestive tract.

What you should do

You can take these medicines together. However, you should monitor for any new or worsening side effects, such as nausea, diarrhoea, or stomach pain. If you take both long-term, ask your doctor to check your Vitamin B12 levels during your routine blood tests.

Important precautions

Lactic acidosis risk

If you experience severe vomiting, diarrhoea, or dehydration, stop taking metformin and seek medical help immediately. This prevents a rare but serious build-up of acid in the blood.

Vitamin B12 deficiency

Long-term use can lower your vitamin B12 levels. If you feel unusually tired or have a sore, red tongue, ask your doctor to check your levels.

Contrast dye scans (e.g., CT or X-ray)

You must tell your doctor you take metformin if you are having a scan involving an injection of 'contrast dye'. You will usually need to stop taking metformin 48 hours before and after the procedure to prevent kidney damage.

Severe diarrhoea

Lansoprazole can increase your risk of serious bowel infections. If you develop severe or persistent watery diarrhoea, or a fever, contact your doctor immediately and do not take anti-diarrhoeal medicine.

Lupus (SLE) or skin reactions

Contact your doctor if you develop a skin rash, especially in areas exposed to the sun, as lansoprazole can cause a rare but serious autoimmune skin reaction.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking lansoprazole. Alcohol increases the amount of acid your stomach produces, which can make your symptoms worse and counteract the effects of the medicine.

It is best to avoid or strictly limit alcohol while taking metformin. Combining alcohol with metformin 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).

Food (Timing)

Lansoprazole works best if you take it at least 30 minutes before food. Taking it with or after food can make it less effective at reducing stomach acid.

Caffeine (Coffee, Tea, Energy Drinks)

Lansoprazole is often prescribed for acid reflux. Caffeine can trigger or worsen reflux symptoms by relaxing the muscle at the base of the food pipe, which may make your medicine less effective at managing your symptoms.

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.