Avanafil Dizziness: Causes, Duration & What to Do

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Avanafil Dizziness: How Common, Why It Happens & What to Do

Published: 15 November 2026

Avanafil dizziness is a recognised side effect of this erectile dysfunction medicine, though it affects only a small proportion of users. Avanafil (sold as Spedra in the UK) belongs to a group of medicines called PDE5 inhibitors, which work by relaxing blood vessels to improve blood flow to the penis during sexual stimulation. Because these medicines also affect blood vessels elsewhere in the body, they can sometimes cause a temporary drop in blood pressure, leading to feelings of lightheadedness or dizziness. Most cases are mild, short-lived, and manageable with simple precautions.

How Common Is Avanafil Dizziness?

Dizziness is listed as an uncommon side effect of avanafil, meaning it affects fewer than 1 in 100 people who take the medicine [6]. In clinical trials, dizziness was reported less frequently with avanafil than with some other PDE5 inhibitors, partly because avanafil acts quickly and is cleared from the body relatively fast [11]. Most men who experience dizziness find it mild and temporary, occurring shortly after taking the tablet.

The likelihood of dizziness may be higher if you take avanafil alongside certain other medicines, particularly those that lower blood pressure. Alpha-blockers (such as tamsulosin or doxazosin, often prescribed for prostate symptoms) can add to the blood-pressure-lowering effect of avanafil, increasing the risk of dizziness or lightheadedness [6]. Your prescriber will check all your current medicines during the online consultation to identify any potential interactions and adjust your dose if necessary.

Starting on the lowest effective dose of avanafil (usually 50 mg or 100 mg) can help minimise the risk of side effects, including dizziness. If you do experience dizziness, it does not necessarily mean you cannot continue using avanafil; often, simple adjustments or precautions can make a significant difference.

Why Does Avanafil Cause Dizziness?

Avanafil works by inhibiting an enzyme called phosphodiesterase type 5 (PDE5), which allows blood vessels in the penis to relax and widen, improving blood flow during sexual arousal [6]. However, PDE5 is also present in blood vessels throughout the body, so avanafil can cause a mild, temporary widening of blood vessels elsewhere, leading to a small drop in blood pressure. When blood pressure falls, you may feel lightheaded, dizzy, or faint, especially when standing up quickly.

This effect is usually most noticeable within the first hour or two after taking avanafil, when the medicine reaches its peak concentration in the bloodstream. Dehydration, heavy alcohol consumption, or taking avanafil on an empty stomach can make dizziness more likely. Combining avanafil with other medicines that lower blood pressure—such as alpha-blockers, some antihypertensives, or nitrates (which must never be taken with any PDE5 inhibitor)—can significantly increase the risk [6].

It is important to declare all your current medicines, including over-the-counter products and supplements, during your consultation. Your prescriber will check for interactions and ensure avanafil is safe and appropriate for you. Never take avanafil with nitrates (such as GTN spray or isosorbide mononitrate), nicorandil, riociguat, or recreational drugs known as 'poppers', as the combination can cause a dangerous drop in blood pressure.

Other Factors That May Increase Dizziness

Certain lifestyle factors can make dizziness more likely when taking avanafil. Drinking large amounts of alcohol before or after taking the medicine can add to the blood-pressure-lowering effect and worsen dizziness. Alcohol also impairs erectile function, so it is best to limit your intake if you are planning to use avanafil [6]. Dehydration, particularly in hot weather or after exercise, can also contribute to lightheadedness. Ensuring you are well-hydrated and avoiding excessive alcohol can help reduce the risk of dizziness.

How Long Does Avanafil Dizziness Last?

For most men, avanafil dizziness is short-lived and resolves within a few hours as the medicine is metabolised and cleared from the body. Avanafil is one of the faster-acting PDE5 inhibitors, typically taking effect within 15 to 30 minutes, and its effects usually last for around four to six hours [6][11]. Dizziness, if it occurs, tends to be most noticeable during the first one to two hours after taking the tablet, when blood levels of the medicine are highest.

If you experience dizziness, sitting or lying down until the feeling passes is usually sufficient. Avoid sudden movements, such as standing up quickly from a sitting or lying position, as this can make lightheadedness worse. Drinking a glass of water and resting in a cool, quiet place can also help. In the vast majority of cases, dizziness will resolve on its own without the need for medical intervention.

If dizziness persists for several hours, becomes severe, or is accompanied by other concerning symptoms such as chest pain, fainting, or a rapid heartbeat, seek medical advice promptly. Persistent or severe dizziness may indicate an excessive drop in blood pressure or an interaction with another medicine, and your prescriber may need to review your treatment.

Self-Care Tips to Manage Avanafil Dizziness

There are several practical steps you can take to reduce the likelihood of dizziness when using avanafil. First, take the medicine as directed by your prescriber, usually about 15 to 30 minutes before sexual activity, and do not exceed the recommended dose [6]. Taking more than the prescribed amount will not improve the effectiveness of the medicine but will increase the risk of side effects, including dizziness.

Avoid drinking large amounts of alcohol before or after taking avanafil, as alcohol can add to the blood-pressure-lowering effect and make dizziness more likely. Staying well-hydrated by drinking water throughout the day can also help. If you are taking avanafil for the first time, consider using it at a time when you are at home and can rest if you feel lightheaded, rather than before an important event or when you need to drive.

When standing up from a sitting or lying position, do so slowly to give your body time to adjust and minimise the risk of a sudden drop in blood pressure. If you feel dizzy, sit or lie down immediately and avoid activities that require concentration or coordination, such as driving or operating machinery, until the feeling passes. If dizziness occurs regularly or is bothersome, speak to your prescriber; they may suggest a lower dose or an alternative ED medicine that may suit you better.

When to Avoid Avanafil

Avanafil is not suitable for everyone. Do not take avanafil if you are using nitrates (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs known as 'poppers', as the combination can cause a dangerous fall in blood pressure [6]. If you have very low blood pressure, severe heart failure, unstable angina, or have had a recent heart attack or stroke, avanafil may not be safe for you. Always complete the online consultation honestly so your prescriber can assess your suitability.

When to Seek Urgent Help for Dizziness

While mild, short-lived dizziness is usually not a cause for concern, certain symptoms require urgent medical attention. If you experience severe dizziness accompanied by chest pain, difficulty breathing, or a rapid or irregular heartbeat, call 999 or go to A&E immediately, as these may be signs of a serious cardiovascular problem [6]. Fainting or losing consciousness after taking avanafil also warrants urgent assessment.

If you develop an erection that lasts longer than four hours (a condition known as priapism), seek emergency medical help straight away, even if the erection is not painful. Priapism is a rare but serious side effect that can cause permanent damage to the penis if not treated promptly [6]. Similarly, sudden loss of vision or hearing after taking avanafil requires immediate medical attention, as these are rare but serious side effects.

If dizziness is persistent, severe, or accompanied by other unusual symptoms such as severe headache, confusion, or weakness, contact your GP or NHS 111 for advice. Your prescriber may need to review your treatment and check for interactions with other medicines or underlying health conditions that could be contributing to your symptoms.

Alternatives If Avanafil Dizziness Persists

If dizziness continues to be a problem despite taking precautions, or if it is affecting your quality of life, speak to your prescriber about alternative options. Other PDE5 inhibitors, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra), work in a similar way to avanafil but have different pharmacokinetic profiles and may be better tolerated by some men [3][4][5]. For example, tadalafil has a longer duration of action (up to 36 hours) and can be taken as a lower daily dose, which may result in fewer peaks and troughs in blood levels and a lower risk of side effects like dizziness.

Your prescriber will consider your medical history, other medicines you are taking, and your preferences when recommending an alternative. All PDE5 inhibitors are available through Cured Pharmacy after an online consultation reviewed by a UK-registered prescriber. If PDE5 inhibitors are not suitable or effective for you, other treatments such as Vitaros (alprostadil cream) or Caverject (alprostadil injection) may be considered, though these require a prescription and are used differently [7].

It is also worth addressing any underlying lifestyle factors that may be contributing to erectile dysfunction, such as smoking, excessive alcohol consumption, lack of exercise, or stress. Making positive changes to your overall health can improve erectile function and may reduce your reliance on medication. If erectile dysfunction is new or worsening, see your GP for a full assessment, as it can be an early warning sign of cardiovascular disease or diabetes [1][2].

How Cured Pharmacy Can Help

Cured Pharmacy is a GPhC-registered online pharmacy (GPhC 9012511) offering discreet, convenient access to erectile dysfunction treatments. All prescription medicines, including Spedra (avanafil), are supplied only after an online consultation reviewed by a UK-registered prescriber. If you are experiencing persistent dizziness or other side effects, our prescribers can review your treatment, adjust your dose, or recommend an alternative medicine that may suit you better. Use code Ednew at checkout for a discount on your first order.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 15 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 15 November 2026]
3. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 15 November 2026]
4. National Institute for Health and Care Excellence. (2014). Erectile dysfunction: avanafil (ESNM45). https://www.nice.org.uk/advice/esnm45 [accessed 15 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.