Who should not take avanafil (Spedra)?

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Key takeaways

• Never take avanafil with nitrates, nicorandil, riociguat, or poppers due to dangerous blood pressure drops
• Avanafil is contraindicated with potent CYP3A4 inhibitors like ritonavir, ketoconazole, and itraconazole
• Not suitable if you have had a heart attack or stroke in the last six months
• Alpha-blocker users need special caution and should start on the lowest avanafil dose
• All current medicines are reviewed during your online consultation to check for interactions

Who should not take avanafil due to medication interactions?

Avanafil must never be taken alongside certain medicines because of serious drug interactions [6]. The most critical contraindication is with nitrate medicines, which are commonly prescribed for chest pain (angina). These include GTN spray, isosorbide mononitrate, and isosorbide dinitrate. Taking avanafil with nitrates can cause a severe and potentially life-threatening fall in blood pressure [6].

Nicorandil, another angina medicine, and riociguat (used for pulmonary hypertension) are also absolute contraindications [6]. Recreational drugs known as 'poppers' (amyl or alkyl nitrites) work in a similar way to nitrates and must never be combined with avanafil. You should also never take avanafil at the same time as another PDE5 inhibitor such as sildenafil, tadalafil, or vardenafil [6].

Potent CYP3A4 inhibitors significantly raise avanafil levels in the blood and are contraindicated. These include HIV medicines like ritonavir and cobicistat (including in Paxlovid), antifungal medicines such as ketoconazole and itraconazole, and the antibiotic clarithromycin [6]. If you are taking any of these medicines, avanafil is not suitable for you. During your online consultation at Cured Pharmacy, the prescriber will review all your current medicines to check for interactions before approving treatment.

Medical conditions that make avanafil unsuitable

Certain cardiovascular conditions mean avanafil should not be used. If you have had a heart attack or stroke within the last six months, avanafil is contraindicated [6]. Unstable angina (chest pain that occurs unpredictably or at rest) is another absolute contraindication, as sexual activity itself may be inadvisable in this situation [6].

Severe heart failure (particularly New York Heart Association Class III or IV) and very low blood pressure (hypotension) also make avanafil unsuitable [6]. If you have uncontrolled high blood pressure, this needs to be stabilised before considering any erectile dysfunction treatment. People with severe liver impairment (Child-Pugh Class C) should not take avanafil, as the medicine is broken down by the liver and can accumulate to unsafe levels [6].

Avanafil is also contraindicated if you have previously experienced non-arteritic anterior ischaemic optic neuropathy (NAION), a rare condition causing sudden vision loss [6]. Certain inherited retinal disorders, such as retinitis pigmentosa, are also listed as contraindications in the product information [6]. If you have any serious kidney problems, your doctor will need to assess whether avanafil is appropriate, as dose adjustments may be needed or the medicine may not be suitable.

When sexual activity itself is not advisable

It is important to recognise that erectile dysfunction treatments like avanafil are only suitable when sexual activity is medically safe for you [6]. If your doctor has advised you to avoid sexual activity due to heart problems or other serious health conditions, then avanafil and other PDE5 inhibitors should not be used. Sexual activity places demands on the heart and cardiovascular system, and in some situations this can be dangerous [2]. Your GP or cardiologist is best placed to advise whether sexual activity is safe for you, particularly if you have a history of heart disease, chest pain, or other cardiovascular conditions.

At a glance

Alpha-blocker medicines and avanafil: important precautions

If you take alpha-blocker medicines for an enlarged prostate (benign prostatic hyperplasia) or high blood pressure, special caution is needed with avanafil. Alpha-blockers include doxazosin, tamsulosin, alfuzosin, terazosin, prazosin, silodosin, and indoramin. While not an absolute contraindication, combining these with avanafil can cause low blood pressure and dizziness [6].

You should be stable on your alpha-blocker treatment before starting avanafil, and your prescriber will usually recommend starting on the lowest dose of avanafil (50 mg) [6]. It is important to declare all alpha-blocker use during your consultation so the prescriber can assess whether the combination is safe for you and provide appropriate dosing advice.

Similarly, if you take other blood-pressure-lowering medicines, these can add to the blood-pressure-lowering effect of avanafil. This does not necessarily mean you cannot take avanafil, but it must be carefully assessed by the prescriber during your consultation. Never stop or change a prescribed medicine without speaking to your doctor or pharmacist first.

Other medicines that may affect avanafil

Moderate CYP3A4 inhibitors, such as erythromycin, diltiazem, and fluconazole, can raise avanafil levels, though to a lesser extent than potent inhibitors [6]. Your prescriber may recommend a lower starting dose if you take these medicines. Conversely, CYP3A4 inducers like rifampicin, carbamazepine, phenytoin, and St John's wort can reduce avanafil effectiveness by speeding up its breakdown in the body [6]. If you are taking any of these, avanafil may not work as well, and your prescriber will discuss alternative options with you.

Who should not take avanafil: age and allergy considerations

Avanafil is licensed for use in adult men aged 18 and over [6]. It is not intended for use in women or children. If you are under 18, avanafil is not suitable for you, and you should speak to your GP about any concerns regarding sexual health.

If you have a known allergy or hypersensitivity to avanafil or any of the ingredients in Spedra tablets, you must not take this medicine [6]. Allergic reactions can range from mild skin rashes to serious anaphylaxis. Always check the patient information leaflet for a full list of ingredients, and inform your prescriber of any known allergies during your consultation.

Men with rare hereditary problems of galactose intolerance, total lactase deficiency, or glucose-galactose malabsorption should not take avanafil tablets, as they contain lactose [6]. If you have any of these conditions, discuss alternative erectile dysfunction treatments with your healthcare provider.

Lifestyle factors and avanafil safety

While not absolute contraindications, certain lifestyle factors can affect the safety and effectiveness of avanafil. Heavy alcohol consumption can worsen erectile dysfunction and add to the blood-pressure-lowering effects of avanafil, increasing the risk of dizziness and fainting [6]. It is best to limit alcohol intake when planning to use avanafil.

Grapefruit and grapefruit juice can raise avanafil levels in the blood by interfering with the enzymes that break it down [6]. While this is not an absolute contraindication, it is advisable to avoid grapefruit products when taking avanafil to reduce the risk of side effects.

If you use recreational drugs, particularly nitrite-based 'poppers', you must not take avanafil. The combination can cause a dangerous drop in blood pressure [6]. Be honest with your prescriber about any recreational drug use so they can assess your suitability for treatment safely. Remember, all information shared during your consultation is confidential and handled in line with professional standards.

When to see your GP before considering avanafil

If you are experiencing erectile dysfunction for the first time, it is important to see your GP before seeking treatment online [1][2]. Erectile dysfunction can be an early warning sign of underlying health conditions such as heart disease, diabetes, or high blood pressure [1]. Your GP can perform appropriate tests and investigations to identify any underlying causes and ensure that treatment is safe and appropriate for you. Once any underlying conditions are managed, your GP can advise whether avanafil or another erectile dysfunction treatment is suitable.

How Cured Pharmacy assesses suitability for avanafil

At Cured Pharmacy, all erectile dysfunction treatments, including avanafil (Spedra), are prescription-only medicines that require a clinical assessment by a UK-registered prescriber. When you complete an online consultation, you will be asked detailed questions about your medical history, current medicines, allergies, and any health conditions you have [2].

The prescriber will review your answers to check for any contraindications or interactions that would make avanafil unsuitable for you. This includes checking for nitrate use, recent cardiovascular events, severe liver or kidney problems, and use of potent CYP3A4 inhibitors [6]. If avanafil is not appropriate, the prescriber may suggest an alternative treatment or recommend that you see your GP for further assessment.

If avanafil is deemed safe and suitable, the prescriber will approve your order and issue a prescription. Your medicine will then be dispensed by our GPhC-registered pharmacy and delivered discreetly to your door. You can also contact our pharmacy team at any time if you have questions about your treatment or experience any side effects. Spedra (avanafil) is available from £20.95, or £16.76 for your first order with code Ednew.

When to get urgent help

• Chest pain during or after sex—call 999 and do not take nitrates if you have used avanafil in the last 48 hours
• Erection lasting more than 4 hours (priapism)—go to A&E immediately to prevent permanent damage
• Sudden loss of vision or hearing—stop avanafil and seek urgent medical attention
• Severe dizziness, fainting, or signs of very low blood pressure—call 999 or go to A&E
• Allergic reaction with swelling of the face, lips, or throat, or difficulty breathing—call 999

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

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