Avanafil Nausea: Causes, Duration & What to Do

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Key takeaways

• Avanafil nausea is uncommon, affecting fewer than 1 in 100 users, and is usually mild and temporary.
• Nausea typically resolves within a few hours as the medicine is cleared from your system.
• Taking avanafil with a light meal, staying hydrated, and avoiding alcohol can help reduce nausea.
• If nausea persists, your prescriber can adjust your dose or suggest an alternative ED treatment.
• Seek urgent help if nausea is accompanied by chest pain, sudden vision or hearing loss, or an erection lasting over four hours.

How Common Is Avanafil Nausea?

Nausea is classified as an uncommon side effect of avanafil, meaning it affects fewer than 1 in 100 people who take the medicine [6]. In clinical trials, the majority of men experienced no digestive upset at all. When nausea does occur, it is usually mild and temporary, resolving on its own without needing to stop treatment.

The likelihood of experiencing nausea may be slightly higher at the 200mg dose compared to lower doses such as 100mg or 50mg [11]. However, individual responses vary considerably, and many men take the higher dose without any stomach-related side effects. Other common side effects of avanafil include headache and flushing, which are more frequently reported than nausea [6].

If you experience nausea after taking avanafil, it does not necessarily mean you cannot continue using the medicine. Many side effects diminish as your body adjusts to the treatment over the first few doses. Keeping a note of when nausea occurs and how severe it is can help your prescriber decide whether to adjust your dose or suggest a different approach.

Why Does Avanafil Cause Nausea?

Avanafil 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 [6]. This same mechanism can also affect blood vessels elsewhere in the body, including those in the digestive system. Changes in blood flow and smooth muscle relaxation in the stomach and intestines may contribute to feelings of nausea in some individuals.

Another factor is that PDE5 inhibitors can cause a slight drop in blood pressure, which occasionally leads to dizziness or light-headedness that may be accompanied by nausea [6]. Taking avanafil on an empty stomach, with a large or fatty meal, or alongside alcohol can also increase the chance of digestive upset. Alcohol in particular can worsen both erectile dysfunction and side effects such as nausea and dizziness.

Individual sensitivity plays a role too. Some people are more prone to nausea from any medication, especially when starting a new treatment. Anxiety or stress about sexual performance can also contribute to stomach upset, making it difficult to separate the effect of the medicine from psychological factors. If nausea persists or worsens, it is important to discuss this with your prescriber to rule out other causes.

Interactions That May Worsen Nausea

Certain medicines that interact with avanafil can increase the level of the drug in your bloodstream, potentially raising the risk of side effects including nausea. Potent CYP3A4 inhibitors such as ritonavir, cobicistat, ketoconazole, itraconazole, and clarithromycin can significantly increase avanafil levels, and avanafil is contraindicated or should be avoided with these medicines [6]. Your prescriber will check all your current medications during the online consultation to ensure avanafil is safe for you. Never take avanafil with nitrates, nicorandil, riociguat, or recreational drugs known as poppers, as this combination can cause a dangerous drop in blood pressure [6].

At a glance

How Long Does Avanafil Nausea Last?

Avanafil is a fast-acting PDE5 inhibitor, typically taken 15 to 30 minutes before sexual activity [6]. Its effects usually last for several hours, and most side effects, including nausea, follow a similar timeframe. Nausea related to avanafil typically begins within an hour or two of taking the tablet and usually resolves within a few hours as the medicine is metabolised and cleared from your system.

For most men, any nausea experienced is mild and short-lived, often fading well before the therapeutic window of the medicine ends. If nausea persists beyond a few hours or becomes severe, it is less likely to be a typical side effect and may warrant medical review. Persistent or worsening nausea, especially if accompanied by vomiting, severe abdominal pain, or other concerning symptoms, should be discussed with a healthcare professional.

Some men find that nausea improves after the first one or two doses as their body adjusts to the medicine. If you continue to experience nausea every time you take avanafil, your prescriber may suggest trying a lower dose, switching to a different PDE5 inhibitor, or exploring non-pharmacological strategies to manage the side effect.

Self-Care Tips to Reduce Avanafil Nausea

There are several practical steps you can take to minimise the chance of nausea when taking avanafil. Taking the tablet with a small, light meal rather than on a completely empty stomach can help settle your digestive system, though very heavy or fatty meals may delay absorption and reduce effectiveness. Staying well hydrated throughout the day is also important, as dehydration can worsen feelings of nausea.

Avoid drinking large amounts of alcohol before or after taking avanafil. Alcohol not only increases the risk of side effects such as dizziness and nausea but can also make erectile dysfunction worse and reduce the effectiveness of the treatment [6]. If you do choose to drink, keep it to a small amount and allow time between drinking and taking your dose.

If you feel nauseous after taking avanafil, sitting or lying down in a comfortable position and taking slow, deep breaths can help. Ginger tea, peppermint tea, or plain crackers may also provide relief. Avoid taking additional doses of avanafil or any other ED medicine on the same day, as this increases the risk of side effects. If nausea is accompanied by vomiting, dizziness, or chest pain, seek medical advice promptly.

Adjusting Your Dose

If you are taking the 200mg dose and experiencing nausea, ask your prescriber whether a lower dose such as 100mg or 50mg might be more suitable. Many men achieve good results on lower doses with fewer side effects [11]. Avanafil is available in three strengths, and finding the right balance between effectiveness and tolerability is an important part of personalised treatment. Your prescriber can review your response and adjust your prescription accordingly during your online consultation.

When to Seek Urgent Medical Help

While nausea alone is usually not a cause for alarm, certain symptoms require immediate medical attention. If you experience chest pain during or after sexual activity, stop what you are doing and seek urgent help by calling 999. Chest pain can be a sign of a serious cardiovascular event, and you should not assume it is simply a side effect of the medicine [6].

Sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing, are rare but serious side effects that require immediate medical review. These symptoms may indicate non-arteritic anterior ischaemic optic neuropathy (NAION) or sudden sensorineural hearing loss, both of which have been reported with PDE5 inhibitors [6]. If you notice any sudden changes in your vision or hearing, stop taking avanafil and contact a doctor straight away.

An erection lasting longer than four hours, known as priapism, is a medical emergency that can cause permanent damage to the penis if not treated promptly. If you have an erection that will not go down after four hours, go to A&E immediately [6]. Severe or persistent nausea accompanied by vomiting, severe abdominal pain, dizziness, fainting, or allergic reactions such as swelling of the face, lips, or throat also warrant urgent medical assessment.

Alternative ED Treatments If Avanafil Nausea Persists

If nausea continues to be a problem despite trying a lower dose or self-care measures, there are several alternative erectile dysfunction treatments available. Other PDE5 inhibitors such as sildenafil, tadalafil, and vardenafil work in a similar way to avanafil but have different pharmacokinetic profiles, and some men tolerate one better than another [3][4][5]. Sildenafil is taken about one hour before sex and is available from £0.45 per tablet, while tadalafil can be taken on-demand or as a daily low dose and offers effects lasting up to 36 hours, priced from £7.95 [4].

Vardenafil is another option, typically taken 25 to 60 minutes before sexual activity, and is available from £16.95 [5]. Each PDE5 inhibitor has a slightly different side-effect profile, and switching to a different one may reduce or eliminate nausea. Your prescriber can discuss the pros and cons of each medicine based on your medical history, lifestyle, and any other medications you are taking.

For men who do not respond well to oral tablets or prefer a non-systemic approach, topical treatments such as Eroxon gel (a medical device available without prescription) or prescription alprostadil cream (Vitaros) may be considered [7]. Alprostadil injections (Caverject) are another option for more severe cases, though these require training and are typically reserved for men who have not responded to oral treatments [7]. A consultation with your GP or a specialist can help identify the most appropriate alternative if avanafil is not suitable for you.

Lifestyle and Psychological Support

Erectile dysfunction often has both physical and psychological components, and addressing underlying causes such as stress, anxiety, relationship issues, or lifestyle factors can improve outcomes [1][2]. Regular exercise, a balanced diet, maintaining a healthy weight, stopping smoking, and reducing alcohol intake all support better erectile function and overall cardiovascular health [1]. Psychological therapies such as cognitive behavioural therapy (CBT) or couples counselling may also be beneficial, particularly if performance anxiety is a contributing factor. Your GP can refer you to appropriate services if needed.

When to get urgent help

• Chest pain during or after sexual activity – call 999 immediately
• Sudden loss of vision or hearing – stop taking avanafil and seek urgent medical help
• Erection lasting longer than 4 hours – go to A&E straight away
• Severe or persistent vomiting, severe abdominal pain, or signs of allergic reaction such as swelling of the face, lips, or throat
• Severe dizziness or fainting – seek same-day medical advice

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