Can I take Omeprazole and Venlafaxine together?

Why this happens

Omeprazole can slow down the liver enzymes (specifically CYP2C19) that are responsible for breaking down venlafaxine. Because the body processes the venlafaxine more slowly, the drug can build up to higher levels than intended.

What you should do

You can usually take these medicines together, but you should be aware of any new or worsening side effects. If you feel unusually agitated, confused, or experience a very fast heartbeat, contact your doctor. Your doctor may choose to adjust your dose of venlafaxine if you need to take omeprazole long-term.

Important precautions

Mental health and mood disorders

Venlafaxine can cause an increase in suicidal thoughts or self-harm, particularly when first starting treatment or changing doses. Monitor your mood closely and seek urgent medical help if you notice any distressing changes.

Serotonin syndrome

When taken together, these medicines can increase the risk of serotonin syndrome, a rare but serious reaction. Seek immediate medical attention if you experience agitation, hallucinations, fast heartbeat, or severe muscle stiffness.

Increased bleeding risk

Venlafaxine can increase your risk of bleeding, particularly in the stomach. Taking it with omeprazole may sometimes mask the symptoms of a stomach ulcer, so report any unusual bruising or dark, tarry stools to your doctor immediately.

Severe diarrhoea

Contact your doctor immediately if you develop severe or persistent watery diarrhoea, as omeprazole can increase the risk of a serious bowel infection called Clostridium difficile.

Vitamin B12 deficiency

Long-term use of omeprazole can prevent your body from absorbing Vitamin B12 properly, which may lead to nerve damage or anaemia.

Lupus (SLE)

Seek medical advice if you develop a skin rash, especially in areas exposed to the sun, as omeprazole can trigger or worsen a rare autoimmune condition called Subacute Cutaneous Lupus Erythematosus.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking venlafaxine. Combining the two can increase drowsiness, dizziness, and impair your coordination. It may also worsen the symptoms of your underlying condition.

It is best to avoid or strictly limit alcohol while taking omeprazole. Alcohol can increase the amount of acid your stomach produces, which may worsen your symptoms or make the medicine less effective. Additionally, both alcohol and omeprazole can irritate the stomach lining.

Caffeine (Coffee, tea, energy drinks)

Venlafaxine can increase levels of serotonin in the body. High intake of caffeine can sometimes worsen side effects like jitteriness, anxiety, or a rapid heartbeat when taken with this medicine.

General Food Timing

Omeprazole works best if you take it 30 to 60 minutes before a meal, preferably breakfast. Taking it with food can slow down how quickly the medicine starts to work.

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.