Can I take Venlafaxine and Sildenafil together?

Why this happens

Sildenafil works by widening blood vessels to increase blood flow, which can lower blood pressure. Venlafaxine can also cause changes in blood pressure (usually an increase, but sometimes a drop when standing up). When used together, these effects can lead to an unpredictable drop in blood pressure. Furthermore, venlafaxine is an antidepressant that can cause sexual dysfunction, potentially counteracting the desired effects of sildenafil.

You should use this combination with caution. When starting sildenafil or increasing your dose, be mindful of how you feel when standing up from a sitting or lying position. If you feel dizzy or faint, sit or lie down immediately. It is best to avoid or strictly limit alcohol, as it can worsen these side effects. If you find that sildenafil is not working well for you, or if you experience severe dizziness, speak to your doctor.

Depression and anxiety 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.

Nitrate medication use

NEVER take sildenafil if you use nitrate medicines for chest pain (e.g. glyceryl trinitrate, isosorbide mononitrate) or 'poppers'. Combining them causes a dangerous, potentially fatal drop in blood pressure.

Bleeding disorders

Venlafaxine can increase your risk of bleeding, especially if you are also taking aspirin, NSAIDs (like ibuprofen), or blood-thinning medicines like warfarin. Seek medical advice if you notice unusual bruising or bleeding.

Sudden vision loss or priapism

Seek immediate medical help if you experience a sudden decrease or loss of vision, or if you have an erection that lasts for more than 4 hours.

Serotonin Syndrome

Combining venlafaxine with other medicines that affect serotonin (such as St John's Wort or certain painkillers) can cause a life-threatening condition called serotonin syndrome. Symptoms include agitation, hallucinations, fast heartbeat, and muscle stiffness.

Alcohol

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

It is best to avoid or strictly limit alcohol when taking sildenafil. Alcohol can make it more difficult to get an erection and can also increase the risk of side effects such as dizziness and low blood pressure.

Grapefruit juice

Grapefruit juice can increase the amount of sildenafil in your bloodstream. This makes side effects like headaches, flushing, or low blood pressure more likely. It is best to avoid drinking large amounts of grapefruit juice while using this medicine.

High-fat meals

If you take sildenafil with a heavy or high-fat meal (such as a burger or chips), the medicine may take longer to start working.

Caffeine

Venlafaxine can sometimes increase your blood pressure or heart rate. Consuming high amounts of caffeine (found in coffee, tea, and energy drinks) may worsen these effects or increase feelings of anxiety and restlessness.

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.