Vardenafil Overdose Symptoms: What to Look For

Vardenafil Overdose Symptoms: What You Need to Know

Published: 9 November 2026

Vardenafil overdose symptoms typically include severe dizziness, fainting, visual disturbances, prolonged or painful erection (priapism), and dangerously low blood pressure [5]. While vardenafil (the active ingredient in Levitra) is generally safe when taken as prescribed, taking more than the recommended dose significantly increases the risk of serious side effects. Understanding the signs of overdose and knowing when to seek urgent medical help can protect your health and safety.

What Are the Main Vardenafil Overdose Symptoms?

The most common vardenafil overdose symptoms include severe dizziness, light-headedness, and fainting due to a dangerous drop in blood pressure [5]. You may also experience visual disturbances such as blurred vision, increased sensitivity to light, or a blue tinge to your vision. Headache, flushing, and nasal congestion—which can occur at normal doses—may become much more intense after an overdose.

One of the most serious overdose symptoms is priapism, an erection lasting more than four hours that can be painful and requires emergency treatment to prevent permanent damage to the penis [5]. Other warning signs include chest pain, irregular heartbeat, severe nausea or vomiting, and sudden loss of vision or hearing. If you experience any of these symptoms after taking vardenafil, seek immediate medical attention by calling 999 or going to A&E.

The severity of symptoms depends on how much vardenafil was taken, whether it was combined with other medicines (especially nitrates or other blood-pressure-lowering drugs), and individual factors such as age, liver or kidney function, and underlying health conditions [5]. Even a modest overdose can be dangerous if vardenafil is taken with medicines it interacts with, so always disclose all your current medications during your consultation.

How Much Vardenafil Is Too Much?

The maximum recommended dose of vardenafil is 20 mg in a 24-hour period [5]. Taking more than this amount is considered an overdose and significantly increases the risk of serious side effects. Vardenafil is available in 5 mg, 10 mg, and 20 mg tablets, and your prescriber will recommend the lowest effective dose based on your individual circumstances, medical history, and response to treatment.

For most men, the starting dose is 10 mg, taken about 25 to 60 minutes before sexual activity, with a maximum of one dose per day [5]. Some men may need a lower 5 mg dose if they have certain health conditions, are taking medicines that interact with vardenafil, or are over 65 years old. Others may be increased to 20 mg if the 10 mg dose is well tolerated but not fully effective. Never increase your dose without consulting your prescriber.

If you have liver or kidney problems, or if you are taking potent CYP3A4 inhibitors such as ritonavir, ketoconazole, itraconazole, or clarithromycin, your prescriber may recommend avoiding vardenafil altogether or prescribing a much lower dose [5]. Taking a standard dose in these circumstances can have the same effect as an overdose. Always complete an honest online consultation so your prescriber can assess whether vardenafil is safe for you and determine the correct dose.

What If You Accidentally Take Two Doses?

If you accidentally take two doses of vardenafil within 24 hours, contact NHS 111 immediately for advice, even if you feel well [5]. Do not wait for symptoms to appear. If you develop severe dizziness, fainting, chest pain, or a prolonged erection, call 999 or go to A&E straight away. Take the medicine packet or patient information leaflet with you so healthcare professionals know exactly what you have taken and how much.

What Should You Do If You Suspect a Vardenafil Overdose?

If you or someone else has taken more vardenafil than prescribed, seek urgent medical help immediately by calling 999 or going to your nearest A&E department [5]. Do not wait to see if symptoms develop—early treatment can prevent serious complications. Take the medicine packet, any remaining tablets, and the patient information leaflet with you so medical staff can see exactly what has been taken and when.

While waiting for help, the person should lie down with their legs raised to help maintain blood pressure if they feel dizzy or faint. Do not give them anything to eat or drink unless advised by a healthcare professional. If they lose consciousness but are breathing, place them in the recovery position and stay with them until the ambulance arrives. If they stop breathing, begin CPR if you are trained to do so and call 999 if you have not already done so.

At the hospital, treatment for vardenafil overdose is supportive and focuses on managing symptoms [5]. This may include monitoring blood pressure and heart rate, intravenous fluids to support circulation, and specific treatments for complications such as priapism. There is no specific antidote for vardenafil overdose, so prevention by taking only the prescribed dose is essential. Never share your medicine with others, and store it safely out of reach of children.

Can Vardenafil Overdose Symptoms Occur at Normal Doses?

Some men may experience symptoms similar to vardenafil overdose symptoms even when taking the correct dose, particularly if they have certain risk factors or are taking interacting medicines [5]. For example, combining vardenafil with nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, or recreational drugs called 'poppers' (amyl or alkyl nitrites) can cause a dangerous drop in blood pressure that mimics overdose, even at low doses. This combination is absolutely contraindicated and can be life-threatening.

Alpha-blockers used for prostate problems or high blood pressure (such as doxazosin, tamsulosin, or alfuzosin) can also increase the risk of low blood pressure and dizziness when taken with vardenafil [5]. If you take an alpha-blocker, you should be stable on that medicine before starting vardenafil, and your prescriber will recommend the lowest dose of vardenafil. Other blood-pressure medicines may also add to the blood-pressure-lowering effect, though this is usually manageable with careful prescribing.

Potent CYP3A4 inhibitors—medicines that slow the breakdown of vardenafil in the body—can raise vardenafil levels to the point where a normal dose has the effect of an overdose [5]. These include HIV medicines (ritonavir, cobicistat, Paxlovid), antifungals (ketoconazole, itraconazole), and certain antibiotics (clarithromycin). Vardenafil is often contraindicated or requires significant dose reduction with these medicines. Always declare every medicine, supplement, and recreational substance you use during your consultation so your prescriber can check for interactions.

When to Contact Your Prescriber About Side Effects

If you experience troublesome side effects at your prescribed dose—such as persistent headache, dizziness, flushing, or indigestion—contact your prescriber for advice [5]. These are common side effects that may settle with time or may indicate that a lower dose would be more suitable. Do not simply stop taking vardenafil or increase the dose on your own; your prescriber can adjust your treatment plan safely.

How to Prevent Vardenafil Overdose and Stay Safe

Preventing vardenafil overdose symptoms starts with taking only the dose prescribed to you and never exceeding one dose in 24 hours [5]. Set a reminder on your phone or mark your calendar after taking a dose to avoid accidentally taking a second one. Store vardenafil in its original packaging in a cool, dry place away from children and pets, and never share your medicine with others, even if they have similar symptoms—what is safe for you may be dangerous for someone else.

Always complete your online consultation honestly and thoroughly, declaring all medicines you currently take (including over-the-counter medicines, herbal remedies, and supplements), all health conditions, and any recreational substances you use [5]. Your prescriber uses this information to check for interactions and contraindications and to determine the safest dose for you. If your health changes or you start a new medicine, contact your prescriber before taking your next dose of vardenafil to ensure it is still safe.

Avoid drinking large amounts of alcohol when taking vardenafil, as alcohol can worsen erectile dysfunction, increase the risk of side effects such as dizziness and low blood pressure, and impair your judgement about safe dosing [5]. Grapefruit juice can also raise vardenafil levels in the blood and should be avoided. If you have any questions or concerns about your vardenafil treatment, contact the pharmacy or your prescriber—never guess or rely on advice from friends or unqualified sources online.

Understanding Vardenafil Overdose Symptoms and Other ED Treatments

Vardenafil is one of several PDE5 inhibitor medicines licensed in the UK for erectile dysfunction [2]. The others are sildenafil (Viagra), tadalafil (Cialis), and avanafil (Spedra). All work in a similar way by increasing blood flow to the penis during sexual stimulation, and all carry a risk of overdose if taken in excessive amounts or combined with certain medicines [3][4][5][6]. The symptoms of overdose are broadly similar across all PDE5 inhibitors, though the duration and severity may vary.

If you have experienced troublesome side effects with vardenafil, or if you are concerned about the risk of overdose, speak to your prescriber about whether a different PDE5 inhibitor might be more suitable [2]. For example, sildenafil and vardenafil are shorter-acting (effects last around 4–5 hours), while tadalafil can last up to 36 hours and is also available as a low-dose daily tablet [3][4][5]. Avanafil works quickly (within 15–30 minutes) and may have a lower risk of certain side effects [6]. Your prescriber can help you choose the option that best fits your lifestyle and health profile.

All prescription ED treatments from Cured Pharmacy are supplied only after an online consultation reviewed by a UK-registered prescriber, ensuring that the medicine is safe and appropriate for you. If you have new or worsening erectile dysfunction, it is important to see your GP, as ED can be an early warning sign of underlying health conditions such as heart disease, diabetes, or high blood pressure [1][2]. Treating these conditions can improve your overall health and may also improve your erectile function.

Alternatives to Oral ED Medicines

If PDE5 inhibitors are not suitable for you—for example, because you take nitrates or have had a recent heart attack—your GP or specialist may recommend alternative treatments such as Vitaros (alprostadil cream applied to the tip of the penis) or Caverject (alprostadil injection into the penis) [7]. Vacuum erection devices and penile implants are also options for some men. Your healthcare provider can discuss the full range of treatments available and help you find the safest and most effective option for your circumstances.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 9 November 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 9 November 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 9 November 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 9 November 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 9 November 2026]
6. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 9 November 2026]
7. Joint Formulary Committee. (n.d.). Alprostadil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/alprostadil/ [accessed 9 November 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.