Vardenafil and Metronidazole: Can You Take Them Together?

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Vardenafil and Metronidazole: Understanding the Interaction

Published: 2 November 2026

Many men wonder whether vardenafil and metronidazole can be taken together safely. The good news is that no major interaction is commonly reported between vardenafil (Levitra) and metronidazole, an antibiotic used to treat bacterial and parasitic infections. However, every medicine you take—whether prescribed, over-the-counter, or herbal—must be declared during your consultation, because your prescriber will check for interactions specific to your full medication list and health history.

What Is Vardenafil and How Does It Work?

Vardenafil is a prescription medicine used to treat erectile dysfunction (ED) in adult men. It belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors, which also includes sildenafil (Viagra), tadalafil (Cialis), and avanafil (Spedra) [5].

Vardenafil works by relaxing the blood vessels in the penis, allowing more blood to flow into the area when you are sexually aroused. This helps you get and keep an erection suitable for sexual activity. It is important to understand that vardenafil does not work without sexual stimulation—it is not an aphrodisiac and will not increase your sex drive [5].

Vardenafil is typically taken about 25 to 60 minutes before sexual activity. The usual starting dose is 10 mg, which can be adjusted by your prescriber to 5 mg or 20 mg depending on how well it works for you and whether you experience any side effects. You should not take vardenafil more than once in any 24-hour period [5].

What Is Metronidazole and What Is It Used For?

Metronidazole is an antibiotic and antiprotozoal medicine used to treat a wide range of bacterial and parasitic infections. It is commonly prescribed for dental infections, bacterial vaginosis, pelvic inflammatory disease, infected leg ulcers or pressure sores, and certain gut infections such as Clostridium difficile [12].

Metronidazole works by entering bacterial and protozoal cells and damaging their DNA, which stops the organisms from growing and multiplying. It is available in several forms, including tablets, capsules, suppositories, and topical preparations such as gels and creams [12].

A typical course of metronidazole tablets is 400 mg taken two or three times a day for five to seven days, though the exact dose and duration depend on the type and severity of the infection being treated. It is important to complete the full course of antibiotics even if you start to feel better, to ensure the infection is fully cleared and to reduce the risk of antibiotic resistance [12].

Common Side Effects of Metronidazole

Common side effects of metronidazole include nausea, a metallic taste in the mouth, loss of appetite, and occasionally headache or dizziness. You should avoid drinking alcohol while taking metronidazole and for at least 48 hours after finishing the course, as the combination can cause severe nausea, vomiting, flushing, and rapid heartbeat [12].

Can You Take Vardenafil and Metronidazole Together?

There is no commonly reported major interaction between vardenafil and metronidazole. These two medicines work in completely different ways and are processed by different pathways in the body, so taking them together is not expected to cause significant problems for most people.

Metronidazole is not known to affect the enzymes (particularly CYP3A4) that break down vardenafil in the liver, so it should not significantly increase or decrease vardenafil levels in your blood. Similarly, vardenafil does not interfere with the antibacterial action of metronidazole [5][12].

However, it is essential to declare all medicines you are taking—including antibiotics like metronidazole—when you request vardenafil or any other ED treatment. Your prescriber will review your full medication list and health history to ensure the combination is safe for you personally. Some people may experience side effects from either medicine that could overlap, such as dizziness or headache, and your prescriber can advise on how to manage these.

If you are taking metronidazole for an infection, you may not feel at your best, and this can sometimes affect your interest in or ability to engage in sexual activity. This is a normal response to being unwell and should improve once the infection clears and you complete your antibiotic course.

What Your Prescriber Checks Before Approving Vardenafil

Before vardenafil can be prescribed, a UK-registered prescriber will review your medical history and current medicines to ensure it is safe and suitable for you. This assessment is carried out through an online consultation at Cured Pharmacy, and every detail you provide is important [2].

Your prescriber will check whether you are taking any medicines that could interact dangerously with vardenafil. You must never take vardenafil if you are using nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites). These combinations can cause a sudden and dangerous drop in blood pressure [5].

If you take alpha-blockers for an enlarged prostate or high blood pressure (such as tamsulosin, doxazosin, or alfuzosin), your prescriber will ensure you are stable on that medicine and will usually start you on the lowest dose of vardenafil to reduce the risk of dizziness or fainting [5].

Certain medicines that strongly inhibit the liver enzyme CYP3A4—such as ritonavir, cobicistat, ketoconazole, itraconazole, and clarithromycin—can raise vardenafil levels significantly. Vardenafil is generally avoided or contraindicated with these potent inhibitors; your prescriber will check the Summary of Product Characteristics (SmPC) if you are taking any of these medicines [5][12].

Declaring All Your Medicines

Always list every medicine you take, including over-the-counter products, herbal remedies, vitamins, and supplements. Even if you think a medicine is unrelated to ED, it may still interact with vardenafil or indicate an underlying health condition that needs to be considered. For example, if you take medicines for high blood pressure, diabetes, or heart disease, your prescriber needs to know [2].

Practical Advice for Taking Vardenafil and Metronidazole

If your prescriber has confirmed it is safe for you to take vardenafil while you are on a course of metronidazole, there are some practical steps you can take to get the best results and minimise side effects.

Take each medicine exactly as prescribed. Vardenafil should be taken about 25 to 60 minutes before you plan to have sex, and you should not take more than one dose in 24 hours. Metronidazole is usually taken two or three times a day with or after food; follow the instructions on your prescription label [5][12].

Avoid drinking alcohol while taking metronidazole and for at least 48 hours after your last dose, as this combination can make you feel very unwell. Alcohol can also worsen erectile dysfunction and may add to the blood-pressure-lowering effect of vardenafil, increasing the risk of dizziness [12].

If you experience side effects from either medicine—such as headache, dizziness, nausea, or flushing—these are usually mild and temporary. Drinking plenty of water, avoiding heavy meals before taking vardenafil, and resting if you feel dizzy can help. If side effects are severe or persistent, contact your prescriber or pharmacist for advice.

Remember that vardenafil requires sexual stimulation to work. If you are feeling unwell because of an infection, it is perfectly normal for your interest in sex to be lower than usual. Once you have completed your antibiotic course and recovered, you should find that vardenafil works as expected.

When to Seek Medical Help and Other Considerations

While vardenafil and metronidazole can usually be taken together without problems, there are some warning signs that require urgent medical attention. If you develop an erection that lasts longer than four hours (priapism), you must go to A&E immediately, as this can cause permanent damage to the penis [5].

Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing (which may be accompanied by ringing in the ears or dizziness), are rare but serious side effects of PDE5 inhibitors. Stop taking vardenafil and seek medical help straight away if this happens [5].

If you experience chest pain during or after sex, do not use nitrate medicines to treat it—tell the healthcare professional that you have taken vardenafil. If you develop severe allergic reactions (such as swelling of the face, lips, tongue, or throat, or difficulty breathing) to either medicine, call 999 immediately [5][12].

If you have new or worsening erectile dysfunction, it is important to see your GP for a full assessment. ED can be an early warning sign of underlying health conditions such as heart disease, high blood pressure, or diabetes, and treating these conditions may improve your erections as well as your overall health [1][2].

At Cured Pharmacy, all ED treatments are supplied only after an online consultation reviewed by a UK-registered prescriber. This ensures that the medicine is safe and appropriate for you, taking into account your current health, other medicines, and any recent changes in your condition.

Lifestyle Factors That Support ED Treatment

Alongside medication, lifestyle changes can improve erectile function. Maintaining a healthy weight, exercising regularly, stopping smoking, reducing alcohol intake, and managing stress all support better erections and overall cardiovascular health. Your prescriber can offer advice tailored to your circumstances [1][2].

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 2 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 2 November 2026]
3. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 2 November 2026]
4. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 2 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.