Avanafil Patient Information Leaflet Explained

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Avanafil Patient Information Leaflet: What You Need to Know

Published: 6 November 2026

The avanafil patient information leaflet is the official document supplied with every pack of Spedra (avanafil), explaining how to take the medicine, what side effects may occur, and important safety warnings. Avanafil is a prescription-only PDE5 inhibitor used to treat erectile dysfunction (ED) in adult men; it works by increasing blood flow to the penis during sexual stimulation, helping you get and keep an erection [6]. This page summarises the key information from the avanafil patient information leaflet in plain language, written by a UK pharmacist, to help you use the medicine safely and effectively.

What is avanafil and how does it work?

Avanafil (brand name Spedra) is a medicine licensed in the UK to treat erectile dysfunction in men aged 18 and over [6]. It belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors, which work by relaxing blood vessels in the penis, allowing more blood to flow in when you are sexually aroused [6]. Avanafil does not cause an erection on its own—sexual stimulation is still needed for it to work [6].

Avanafil is available in three strengths: 50 mg, 100 mg, and 200 mg tablets [6]. The usual starting dose is 100 mg, taken about 15 to 30 minutes before sexual activity [6]. Your prescriber may adjust the dose depending on how well it works and whether you experience side effects. You should not take more than one dose in 24 hours [6]. Avanafil is one of the fastest-acting PDE5 inhibitors, often working within 15 to 30 minutes, though individual response times vary [11].

Because avanafil is a prescription-only medicine, you will need a consultation with a UK-registered prescriber before it can be supplied. At Cured Pharmacy, this is done through a confidential online questionnaire reviewed by a prescriber to ensure the medicine is safe and suitable for you.

How to take avanafil: dosage and timing from the patient information leaflet

The avanafil patient information leaflet recommends taking one tablet with a glass of water approximately 15 to 30 minutes before you plan to have sex [6]. You can take avanafil with or without food, though a very heavy, high-fat meal may delay how quickly it starts to work [6]. The usual starting dose is 100 mg, but your prescriber may start you on 50 mg if you have certain health conditions or take other medicines, or increase the dose to 200 mg if 100 mg is not effective enough [6].

Do not take more than one avanafil tablet in any 24-hour period [6]. Taking more than the recommended dose increases the risk of side effects and does not improve effectiveness. If you accidentally take too much, contact your GP, pharmacist, or NHS 111 for advice. Avanafil only works when you are sexually aroused, so it will not cause an erection without stimulation [6].

If you find that avanafil is not working as well as you hoped, speak to your prescriber before changing the dose or trying a different medicine. Sometimes adjusting the timing, reducing alcohol intake, or addressing underlying health issues can improve results [2].

What to do if you miss a dose

Avanafil is taken only when needed, so there is no regular dosing schedule and no concept of a 'missed dose' [6]. Simply take the next tablet when you plan to have sex, remembering not to take more than one dose in 24 hours [6]. If you have any questions about timing or dosing, your pharmacist or prescriber can give you personalised advice.

Common and serious side effects of avanafil

Like all medicines, avanafil can cause side effects, though not everyone gets them [6]. The most common side effects, affecting up to 1 in 10 men, include headache, flushing (redness or warmth in the face, neck, or chest), nasal congestion, and back pain [6]. These are usually mild and go away on their own within a few hours. Drinking plenty of water and avoiding heavy alcohol can help reduce the likelihood of headache and flushing.

Less common side effects include dizziness, indigestion, nausea, and a faster heartbeat [6]. If you feel dizzy, avoid driving or operating machinery until the feeling passes. Rarely, avanafil can cause more serious side effects such as sudden loss of vision in one or both eyes, sudden decrease or loss of hearing (sometimes with ringing in the ears), or an erection that lasts longer than four hours (priapism) [6]. These require urgent medical attention.

If you experience chest pain during or after sex, do not use nitrate medicines (such as GTN spray) to treat it, as the combination with avanafil can cause a dangerous drop in blood pressure [6]. Instead, seek immediate medical help by calling 999. Always report any unexpected or persistent side effects to your prescriber or pharmacist, and you can also report them via the Yellow Card Scheme at https://yellowcard.mhra.gov.uk/ [12].

Avanafil patient information leaflet: important warnings and contraindications

The avanafil patient information leaflet contains several important warnings that you must read before taking the medicine [6]. Do not take avanafil if you are using nitrate medicines for chest pain (such as glyceryl trinitrate spray, isosorbide mononitrate, or isosorbide dinitrate), nicorandil, riociguat, or recreational drugs called 'poppers' (amyl or alkyl nitrites) [6]. Combining avanafil with any of these can cause a severe and potentially life-threatening drop in blood pressure [6].

You should also not take avanafil if you have had a heart attack or stroke in the last six months, have unstable angina, severe heart failure, very low blood pressure, or a condition called non-arteritic anterior ischaemic optic neuropathy (NAION), which causes sudden vision loss [6]. Avanafil is not suitable if you have certain inherited eye conditions affecting the retina, severe liver disease, or if you are on kidney dialysis [6]. Your prescriber will check your medical history during the consultation to ensure avanafil is safe for you.

If you take medicines for high blood pressure, an enlarged prostate (alpha-blockers such as doxazosin or tamsulosin), or certain antifungal or HIV medicines, tell your prescriber, as dose adjustments or extra monitoring may be needed [6]. Avanafil should not be taken with other PDE5 inhibitors (sildenafil, tadalafil, or vardenafil) or with potent CYP3A4 inhibitors such as ritonavir, cobicistat, ketoconazole, or itraconazole [6]. Grapefruit juice can also increase avanafil levels in your blood and should be avoided [6].

When sexual activity is not advisable

Avanafil, like all ED medicines, should not be used if your doctor has advised you to avoid sexual activity due to heart problems [6]. Sexual activity places extra strain on the heart, and if your cardiovascular system is not healthy enough for this, using avanafil could be dangerous [6]. Always discuss your heart health and fitness for sexual activity with your GP or prescriber before starting treatment [2].

Avanafil interactions: what medicines to avoid

The avanafil patient information leaflet lists several important drug interactions that you must be aware of [6]. As mentioned, never take avanafil with nitrates, nicorandil, riociguat, or poppers, as this can cause a dangerous fall in blood pressure [6]. If you take alpha-blockers for high blood pressure or prostate problems (such as doxazosin, tamsulosin, alfuzosin, or terazosin), you must be stable on that medicine before starting avanafil, and your prescriber will usually start you on the lowest dose of avanafil to reduce the risk of dizziness or fainting [6].

Certain medicines that affect liver enzymes can increase avanafil levels in your blood, raising the risk of side effects [6]. These include potent CYP3A4 inhibitors such as ritonavir, cobicistat (found in some HIV medicines and in Paxlovid, a COVID-19 treatment), ketoconazole, itraconazole, and clarithromycin [6]. Avanafil is contraindicated with these medicines, meaning you should not take them together [6]. Moderate CYP3A4 inhibitors (such as erythromycin, diltiazem, or fluconazole) may also require a lower starting dose of avanafil [6].

Conversely, medicines that speed up liver enzymes (CYP3A4 inducers), such as rifampicin, carbamazepine, phenytoin, and St John's wort, can reduce avanafil levels and make it less effective [6]. If you take any of these, your prescriber may recommend a different ED treatment. Always tell your prescriber and pharmacist about all medicines you take, including over-the-counter products, herbal remedies, and supplements, so they can check for interactions [6].

Where to find the full avanafil patient information leaflet

The complete avanafil patient information leaflet (PIL) is included in every pack of Spedra and provides detailed information about the medicine, including the full list of side effects, warnings, and instructions [12]. You can also read the PIL online before you order by visiting the Electronic Medicines Compendium (eMC) at https://www.medicines.org.uk/emc/, where you can search for 'Spedra' or 'avanafil' to view the most up-to-date version approved by the UK Medicines and Healthcare products Regulatory Agency (MHRA) [12].

If you have any questions after reading the leaflet, your pharmacist is the best person to ask. At Cured Pharmacy, our team is available to answer questions about how to take avanafil, what to do if you experience side effects, and whether it might interact with other medicines you are taking. You can contact us via the website or by phone during opening hours.

Remember that the patient information leaflet is written to cover all possible risks and side effects, so it may sound alarming. Most men take avanafil without any problems, and serious side effects are rare [6][11]. If you are ever unsure or worried, speak to a healthcare professional rather than stopping the medicine suddenly or taking it in a way that differs from the instructions.

Accessing avanafil (Spedra) through Cured Pharmacy

Avanafil is available at Cured Pharmacy under the brand name Spedra, priced at £20.95 for a pack (or £16.76 for your first order with code Ednew). Because it is a prescription-only medicine, you will need to complete a short, confidential online consultation that is reviewed by a UK-registered prescriber. If approved, your medicine is dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. You can view and order Spedra at https://curedpharmacy.com/products/spedra-avanafil-tablets.

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 6 November 2026]
2. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 6 November 2026]
3. National Institute for Health and Care Excellence. (2014). Erectile dysfunction: avanafil (ESNM45). https://www.nice.org.uk/advice/esnm45 [accessed 6 November 2026]
4. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 6 November 2026]
5. NHS. (n.d.). Erectile dysfunction (impotence). https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ Accessed 6 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.

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