Vardenafil and Amantadine: Can They Be Taken Together?

Vardenafil and Amantadine: Understanding the Interaction

Published: 27 October 2026

If you've been prescribed vardenafil and amantadine, you may be wondering whether these two medicines can be taken together safely. The good news is that no major direct interaction between vardenafil (generic Levitra) and amantadine is commonly reported in UK prescribing guidance, but your prescriber will still carefully review your full medication list and health history before approving treatment. This page explains what each medicine does, how they might affect each other, what checks are made during your consultation, and practical steps to use them safely.

What Is Vardenafil and How Does It Work?

Vardenafil is a prescription medicine used to treat erectile dysfunction (ED) in adult men [5]. It belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors, which work by relaxing blood vessels in the penis, allowing increased blood flow when you are sexually aroused [5]. Vardenafil does not cause an erection on its own—sexual stimulation is still needed for it to work [5].

The usual starting dose is 10 mg, taken about 25 to 60 minutes before sexual activity, and it should not be used more than once a day [5]. Your prescriber may adjust the dose to 5 mg or 20 mg depending on how well it works and whether you experience side effects. Common side effects include headache, flushing, nasal congestion, and indigestion [5]. Vardenafil is available at Cured Pharmacy following an online consultation reviewed by a UK-registered prescriber.

What Is Amantadine and Why Is It Prescribed?

Amantadine is a prescription medicine primarily used to treat symptoms of Parkinson's disease and, less commonly, to prevent or treat certain types of influenza A virus infection. In Parkinson's disease, amantadine helps improve movement control, reduce stiffness, and manage involuntary movements (dyskinesia) that can occur as a side effect of long-term levodopa therapy. It works by affecting dopamine activity in the brain and blocking certain receptors involved in movement control.

Amantadine is usually taken once or twice daily, and common side effects can include dizziness, dry mouth, constipation, nausea, and sleep disturbances. Because it can cause dizziness or lightheadedness, especially when standing up, patients are often advised to rise slowly from sitting or lying positions. If you are taking amantadine for Parkinson's disease or another condition, it is essential to tell your prescriber during any consultation for erectile dysfunction treatment so they can review your full medication list and health status.

How Amantadine Affects Blood Pressure and Circulation

Amantadine can occasionally cause a drop in blood pressure when standing (orthostatic hypotension), leading to dizziness or fainting. This is particularly relevant when considering erectile dysfunction treatment, because PDE5 inhibitors like vardenafil also lower blood pressure slightly as part of their mechanism. While the two medicines do not interact directly in a way that is contraindicated, the combination of blood-pressure effects means your prescriber will want to ensure you are not at increased risk of dizziness or falls, especially if you already experience postural symptoms on amantadine.

Vardenafil and Amantadine: Is There a Direct Interaction?

No major direct pharmacological interaction between vardenafil and amantadine is commonly reported in UK prescribing databases or the British National Formulary [5]. This means the two medicines do not interfere with each other's breakdown in the body or block each other's effects in a clinically significant way. However, this does not automatically mean the combination is suitable for everyone—your individual health conditions, other medicines, and overall cardiovascular fitness all play a role in whether vardenafil is safe for you.

During your online consultation at Cured Pharmacy, the prescriber will review your full medication list, including amantadine, and assess whether any additive effects (such as dizziness or low blood pressure) might pose a risk. You should never assume a combination is safe simply because no direct interaction is listed; always declare every medicine, supplement, and over-the-counter product you take, and never stop or change a prescribed medicine without professional advice.

What Your Prescriber Checks Before Approving Vardenafil

Before prescribing vardenafil, a UK prescriber will ask about your cardiovascular health, blood pressure, current medicines (including amantadine), and any history of heart attack, stroke, or severe heart failure [2][5]. They will also check whether you are taking any medicines that are absolutely contraindicated with PDE5 inhibitors—such as nitrates (GTN spray, isosorbide mononitrate or dinitrate), nicorandil, riociguat, or recreational 'poppers' (amyl or alkyl nitrites)—because combining these with vardenafil can cause a dangerous drop in blood pressure [5]. Do not take vardenafil with any of these medicines.

The prescriber will also review whether you take alpha-blockers (such as doxazosin or tamsulosin for prostate symptoms), as these can add to the blood-pressure-lowering effect of vardenafil, increasing the risk of dizziness [5]. If you are stable on an alpha-blocker, you may still be able to use vardenafil, but you will usually start on the lowest dose. Potent CYP3A4 inhibitors (such as ritonavir, ketoconazole, itraconazole, or clarithromycin) can raise vardenafil levels significantly; vardenafil is often avoided or contraindicated in these cases—your prescriber will check the Summary of Product Characteristics if you take any of these [5][12].

Declaring Amantadine and Other Parkinson's Medicines

If you take amantadine for Parkinson's disease, you are likely to be on other medicines as well, such as levodopa, dopamine agonists, or MAO-B inhibitors. It is vital to list all of these during your consultation. While none of these Parkinson's medicines are known to have a major direct interaction with vardenafil, the prescriber needs the full picture to assess your overall cardiovascular risk and ensure that sexual activity itself is safe for you. Parkinson's disease can sometimes be associated with autonomic dysfunction (affecting blood pressure regulation), so your prescriber may ask additional questions about dizziness or fainting episodes.

Practical Advice for Taking Vardenafil and Amantadine Together

If your prescriber approves vardenafil while you are taking amantadine, follow the dosing instructions carefully. Take vardenafil about 25 to 60 minutes before planned sexual activity, and do not use it more than once in 24 hours [5]. Because both medicines can cause dizziness, avoid standing up quickly after taking vardenafil, especially if you already experience postural dizziness on amantadine. Sit on the edge of the bed for a moment before standing, and take your time moving from lying to sitting to standing.

Limit alcohol intake, as heavy drinking can worsen erectile dysfunction and add to the blood-pressure-lowering effects of both medicines, increasing the risk of dizziness or fainting [5]. Avoid grapefruit juice, which can raise vardenafil levels in the blood. If you feel dizzy, lightheaded, or unwell after taking vardenafil, sit or lie down and do not drive or operate machinery. Most side effects are mild and temporary, but if symptoms are severe or persistent, contact your GP or pharmacist for advice.

When to Seek Urgent Medical Help

Seek immediate medical attention if you experience an erection lasting longer than four hours (priapism), as this can cause permanent damage to the penis if not treated promptly [5]. Call 999 or go to A&E if you have sudden loss of vision in one or both eyes, sudden hearing loss or ringing in the ears, or chest pain during or after sexual activity [5]. These are rare but serious side effects that require urgent assessment.

If you develop severe dizziness, fainting, or a rapid or irregular heartbeat after taking vardenafil, stop sexual activity and seek medical help. Do not take another dose of vardenafil or any other PDE5 inhibitor (such as sildenafil or tadalafil) until you have been assessed by a healthcare professional. If you are unsure whether a symptom is serious, contact NHS 111 for advice, or speak to your GP or pharmacist as soon as possible.

Reporting Side Effects and Ongoing Monitoring

If you experience any side effects while taking vardenafil, whether or not they are listed in the patient information leaflet, you can report them via the Yellow Card Scheme at yellowcard.mhra.gov.uk or by searching for 'Yellow Card' in the Google Play or Apple App Store. Reporting helps the UK medicines regulator monitor the safety of medicines. Your GP or specialist may also want to review your Parkinson's treatment and overall health periodically, especially if you start a new medicine like vardenafil, to ensure all your treatments continue to work well together.

Scientific References

1. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 27 October 2026]
2. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 27 October 2026]
3. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 27 October 2026]
4. NHS. (n.d.). Erectile dysfunction (impotence). https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ Accessed 27 October 2026.

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.

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