Vardenafil and Carbamazepine: Can They Be Taken Together?

Takes less than 2 minutes to complete 100% online

What is vardenafil and how does it work?

Vardenafil (also known by the brand name Levitra) is a prescription medicine used to treat erectile dysfunction in adult men [5]. It belongs to a group of medicines called PDE5 inhibitors, which work by relaxing blood vessels in the penis, allowing more blood to flow in when you are sexually aroused.

Vardenafil is available in 5mg, 10mg and 20mg tablets. You typically take it about 25 to 60 minutes before sexual activity, and it works only when you are sexually stimulated [5]. The effects can last for several hours, though this varies between individuals. The usual starting dose is 10mg, taken as needed, with a maximum of one dose per day.

Like all PDE5 inhibitors, vardenafil is broken down (metabolised) in the liver by enzymes, particularly one called CYP3A4. This is important because other medicines that affect this enzyme can change how well vardenafil works or how long it stays in your body [5].

What is carbamazepine and why is it prescribed?

Carbamazepine is a medicine primarily used to treat epilepsy (seizures) and certain types of nerve pain, such as trigeminal neuralgia. It works by stabilising electrical activity in the brain and nerves, helping to prevent seizures and reduce pain signals.

Carbamazepine is also sometimes prescribed for bipolar disorder to help stabilise mood. It is usually taken as a tablet or liquid, often twice a day, and the dose is carefully adjusted by your doctor based on your condition and how you respond to treatment.

One important property of carbamazepine is that it is a potent CYP3A4 inducer. This means it speeds up the activity of the CYP3A4 enzyme in the liver, causing the body to break down certain other medicines more quickly than usual. This can reduce the levels of those medicines in the bloodstream and make them less effective.

Other medicines that work like carbamazepine

Several other medicines are also CYP3A4 inducers and can have a similar effect on vardenafil. These include phenytoin (another anti-epilepsy medicine), rifampicin (an antibiotic used for tuberculosis and other infections), and the herbal remedy St John's wort, which some people take for low mood. If you take any of these, the same interaction applies.

When to get urgent help

• An erection lasting more than 4 hours (priapism) – go to A&E immediately
• Sudden loss of vision in one or both eyes – stop vardenafil and seek urgent medical help
• Chest pain during or after sex – do not use more vardenafil; call 999 if pain is severe or does not go away
• Sudden loss of hearing or ringing in the ears – stop vardenafil and see a doctor urgently
• Severe dizziness, fainting or allergic reaction (swelling, rash, difficulty breathing) – call 999

Call 999 or go to A&E in an emergency, or contact NHS 111 for urgent advice.

How do vardenafil and carbamazepine interact?

When you take vardenafil and carbamazepine together, the carbamazepine speeds up the breakdown of vardenafil in your liver [5]. This means vardenafil is cleared from your body more quickly, so the levels in your bloodstream may be lower than expected. As a result, vardenafil may not work as well or for as long as it would without carbamazepine.

This interaction does not usually cause dangerous side effects or make either medicine unsafe to take. The main concern is reduced effectiveness of the ED treatment, which can be frustrating if you find vardenafil does not help as much as you hoped.

The British National Formulary notes that CYP3A4 inducers like carbamazepine can reduce the plasma concentration of vardenafil, potentially leading to treatment failure [5]. Your prescriber will take this into account when deciding whether vardenafil is the best option for you, or whether a different approach might work better.

What will your prescriber check before prescribing vardenafil and carbamazepine?

During your online consultation at Cured Pharmacy, the prescriber will ask about all the medicines you currently take, including carbamazepine and any other prescription, over-the-counter or herbal products. This is essential to identify any interactions and ensure the treatment is safe and suitable for you.

If you are taking carbamazepine, the prescriber will consider whether vardenafil is likely to be effective enough, or whether an alternative ED medicine might be a better choice. They will also check for any other health conditions or medicines that could affect your treatment, such as heart problems, blood pressure medicines, or other drugs that interact with PDE5 inhibitors.

The prescriber may suggest trying vardenafil at the usual dose first to see how you respond, or they might recommend a different PDE5 inhibitor such as sildenafil or tadalafil, which may be affected differently by carbamazepine. It is important to be honest and thorough when listing your medicines, so the prescriber can give you the safest and most effective advice.

Why you should never adjust doses yourself

You might be tempted to take a higher dose of vardenafil to compensate for the interaction, but this is not safe and should never be done without medical advice. Higher doses increase the risk of side effects such as headaches, flushing, dizziness and visual disturbances. Always follow the dose prescribed for you and discuss any concerns with your prescriber or pharmacist.

At a glance

Practical advice for taking vardenafil with carbamazepine

If your prescriber decides that vardenafil is suitable for you despite taking carbamazepine, take the tablet as directed, usually about 25 to 60 minutes before you plan to have sex. Swallow it whole with water, and remember that sexual stimulation is needed for it to work [5].

Be aware that vardenafil may not work as strongly or as reliably as it would without carbamazepine. If you find it is not effective after trying it on a few separate occasions, contact your prescriber. Do not increase the dose yourself or take it more often than once a day.

Avoid drinking large amounts of alcohol when taking vardenafil, as alcohol can worsen erectile dysfunction and increase the risk of side effects such as dizziness and low blood pressure. Grapefruit juice can also raise vardenafil levels and should be avoided. Continue taking your carbamazepine exactly as prescribed by your doctor; do not stop or change it without medical advice, as this could affect your epilepsy or other condition.

Alternative ED treatments if vardenafil and carbamazepine do not work well together

If vardenafil is not effective enough while you are taking carbamazepine, there are other options. Sildenafil (generic Viagra) and tadalafil (generic Cialis) are also PDE5 inhibitors and may be affected by carbamazepine in a similar way, but individual responses vary and some men find one works better than another [3][4].

Tadalafil has a longer duration of action (up to 36 hours) and can also be taken as a low daily dose, which some men prefer [4]. Avanafil (Spedra) is another PDE5 inhibitor that works more quickly, though it is also metabolised by CYP3A4 [6]. Your prescriber can discuss these alternatives and help you find the most suitable treatment.

If oral ED medicines are not effective or suitable, other treatments are available, including alprostadil cream (Vitaros) applied to the tip of the penis, alprostadil injections (Caverject), vacuum erection devices, or referral to a specialist for further assessment [2][7]. Your GP or prescriber can guide you through these options.

When to see your GP about erectile dysfunction

If you are experiencing erectile dysfunction for the first time, it is important to see your GP for a full assessment. ED can be an early warning sign of underlying health problems such as heart disease, diabetes or high blood pressure [1][2]. Your GP can check for these conditions, review all your medicines, and refer you to a specialist if needed. Online pharmacies like Cured complement NHS care but do not replace a face-to-face medical review when it is needed.

In summary

• Vardenafil and carbamazepine can be taken together but carbamazepine may reduce vardenafil effectiveness.
• Carbamazepine speeds up the breakdown of vardenafil in the liver, lowering its levels in the blood.
• Your prescriber will assess whether vardenafil is suitable or suggest alternative ED treatments.
• Never stop or adjust carbamazepine without medical advice as this can cause serious problems.
• If vardenafil does not work well, contact your prescriber to discuss other options.

Frequently Asked Questions

Ready to Speak to a Pharmacist?

Start your journey to better health today.

• Reviewed by UK-based prescribers
• Takes under 3 minutes
• Discreet Packaging