Avanafil Overdose Symptoms: What You Need to Know

Takes less than 2 minutes to complete 100% online

At a glance

What Are the Key Avanafil Overdose Symptoms?

The most concerning avanafil overdose symptoms relate to its blood-vessel-widening effects becoming excessive [6]. Severe dizziness or light-headedness, particularly when standing up, can indicate a dangerous fall in blood pressure. Some men may experience fainting or near-fainting episodes, which require urgent medical assessment.

Priapism—a painful erection lasting more than four hours—is a medical emergency associated with overdose. This condition can cause permanent damage to the penis if not treated promptly [6]. Visual disturbances, including blurred vision, increased sensitivity to light, or a blue tinge to vision, may also occur with excessive doses.

Other symptoms can include severe headache, flushing that feels unusually intense, rapid or irregular heartbeat, chest pain, and nausea [6]. If you experience any combination of these symptoms after taking avanafil, especially if you've taken more than prescribed, seek immediate medical help. Do not wait to see if symptoms resolve on their own, as some complications can worsen rapidly without treatment.

How Much Avanafil Is Considered an Overdose?

Avanafil is licensed in the UK at doses of 50mg, 100mg, and 200mg, with 100mg being the usual starting dose [6][11]. The maximum recommended dose is 200mg, and you should never take more than one dose in a 24-hour period. Taking more than 200mg in a single dose, or taking multiple doses within 24 hours, constitutes an overdose and significantly increases the risk of serious side effects.

Clinical studies have tested higher doses to assess safety margins, but these were conducted under strict medical supervision [11]. In everyday use, exceeding the prescribed dose offers no additional benefit for erectile function but dramatically raises the likelihood of adverse effects, including the avanafil overdose symptoms described above.

It's particularly important never to combine avanafil with another PDE5 inhibitor such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra) on the same day [6]. This combination effectively creates an overdose situation even if each individual dose is within normal limits. Always follow your prescriber's instructions exactly and never adjust your dose without medical advice.

What Increases Overdose Risk?

Certain medications and health conditions can increase the risk of overdose effects even at normal avanafil doses [6]. Potent CYP3A4 inhibitors—medicines that slow the breakdown of avanafil in your body—include ritonavir, cobicistat (found in some HIV treatments), Paxlovid, ketoconazole, itraconazole, and clarithromycin. These drugs can cause avanafil levels to rise significantly, and in many cases avanafil should be avoided entirely or the dose substantially reduced.

Liver or kidney problems can also affect how your body processes avanafil, potentially leading to higher-than-expected drug levels [6]. Your prescriber will assess these factors during your consultation and adjust the dose accordingly. Never take avanafil if you're using nitrates (GTN spray, isosorbide), nicorandil, riociguat, or recreational drugs called 'poppers', as the combination can cause a life-threatening drop in blood pressure [6].

What Should You Do If You Take Too Much Avanafil?

If you've taken more avanafil than prescribed, contact NHS 111 immediately or attend your nearest A&E department, even if you don't yet have symptoms [12]. Take the medicine packet or patient information leaflet with you so healthcare professionals know exactly what you've taken and how much. Do not drive yourself if you're experiencing dizziness or visual disturbances; call 999 for an ambulance if symptoms are severe.

While waiting for medical help, lie down to reduce the risk of fainting from low blood pressure. Avoid standing up quickly, and don't take any other medicines unless instructed by a healthcare professional. Do not attempt to make yourself sick, as this is unlikely to help once the tablet has been absorbed and may cause additional complications.

Medical treatment for avanafil overdose is supportive, focusing on managing symptoms such as low blood pressure and monitoring for complications [6]. In cases of priapism (erection lasting more than four hours), urgent specialist treatment is needed to prevent permanent damage. Healthcare professionals may also check your heart rhythm and blood pressure, and provide intravenous fluids if needed. Most people recover fully with appropriate medical care, but prompt action is essential to prevent serious complications.

What you need to know

• Avanafil overdose symptoms include severe dizziness, fainting, prolonged erection, and visual disturbances requiring urgent medical help.
• Never take more than 200mg of avanafil in 24 hours or combine it with other PDE5 inhibitors.
• Certain medicines like ritonavil and ketoconazole increase overdose risk even at normal avanafil doses.
• If you take too much avanafil, contact NHS 111 or attend A&E immediately, even without symptoms.
• An erection lasting more than four hours is a medical emergency requiring immediate treatment to prevent permanent damage.

How to Use Avanafil Safely to Avoid Overdose Symptoms

Safe use of avanafil begins with an accurate medical assessment by a UK-registered prescriber [11]. At Cured Pharmacy, every prescription for Spedra (avanafil) follows an online consultation that reviews your medical history, current medications, and any conditions that might affect safety. This process ensures you receive the correct dose and that avanafil is suitable for you.

Always take avanafil exactly as prescribed—typically 100mg about 15 to 30 minutes before sexual activity, with or without food [6][11]. Swallow the tablet whole with water. Never take more than one dose in 24 hours, even if the first dose didn't work as expected. If avanafil isn't effective for you, speak to your prescriber about adjusting the dose or trying a different treatment; don't simply take more.

Store avanafil securely out of reach of children and never share your medication with others, even if they have similar symptoms. Keep a record of when you take each dose to avoid accidental double-dosing. If you're prescribed a new medicine by your GP or another healthcare provider, always mention that you're taking avanafil, as some drug combinations can increase overdose risk [6]. Avoid drinking large amounts of alcohol when using avanafil, as this can worsen side effects and increase the risk of dizziness and low blood pressure.

Recognising Normal Side Effects vs Overdose

It's important to distinguish between common, mild side effects and genuine avanafil overdose symptoms [6]. Mild headache, facial flushing, nasal congestion, and slight dizziness can occur at normal doses and usually settle without treatment. These effects are generally manageable and don't require medical attention unless they're severe or persistent.

However, severe or worsening versions of these symptoms—such as intense headache, extreme dizziness leading to fainting, or visual changes—may indicate overdose or a serious adverse reaction [6]. An erection lasting more than two hours should prompt you to seek medical advice; if it reaches four hours, it's a medical emergency requiring immediate A&E attendance. Trust your instincts: if something feels seriously wrong, seek help rather than waiting to see if it improves.

Understanding Avanafil and Other ED Treatment Options

Avanafil (Spedra) belongs to a class of medicines called PDE5 inhibitors, which also includes sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) [6][11]. All work by improving blood flow to the penis during sexual stimulation, but they differ in how quickly they act and how long they last. Avanafil is one of the fastest-acting options, typically working within 15 to 30 minutes, making it a popular choice for spontaneity.

While avanafil is effective for many men, it's not the only option [2]. Sildenafil has been used for over two decades and is available as a lower-cost generic; tadalafil offers the longest duration of action (up to 36 hours) and can also be taken daily at a lower dose; vardenafil sits between sildenafil and avanafil in terms of onset time. Your prescriber can help you choose the most suitable treatment based on your lifestyle, preferences, and medical history.

All PDE5 inhibitors carry similar risks of overdose and drug interactions, so the safety advice about not exceeding the prescribed dose, avoiding nitrates, and declaring all current medicines applies equally to every option [3][4][5][6]. At Cured Pharmacy, our online consultation process ensures you receive the treatment that's both effective and safe for you, with clear instructions on correct use. Prescription ED medicines are only supplied after a UK prescriber has reviewed your consultation and confirmed suitability.

When to get urgent help

• Erection lasting more than 4 hours (priapism)—go to A&E immediately to prevent permanent damage
• Sudden loss of vision in one or both eyes—call 999 or attend A&E urgently
• Chest pain during or after sexual activity—stop activity and call 999 immediately
• Severe dizziness, fainting, or collapse after taking avanafil—call 999 or attend A&E
• Sudden hearing loss or severe ringing in the ears with dizziness—seek urgent medical assessment

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

When to Seek Medical Advice About Avanafil Overdose Symptoms

Certain avanafil overdose symptoms require immediate emergency care [6]. Call 999 or go straight to A&E if you experience chest pain during or after sex, sudden loss of vision in one or both eyes, sudden decrease or loss of hearing (sometimes with ringing in the ears or dizziness), or an erection lasting more than four hours. These are rare but serious complications that need urgent specialist treatment.

For less severe but concerning symptoms—such as persistent dizziness, severe headache that doesn't respond to simple painkillers, or unusual visual disturbances—contact NHS 111 for advice or see your GP on the same day if possible [12]. Don't ignore symptoms in the hope they'll resolve on their own, especially if you've taken more than the prescribed dose or if you're taking other medicines that might interact with avanafil.

If you're experiencing repeated side effects even at the correct dose, or if avanafil isn't working effectively for you, book a follow-up consultation with your prescriber [2]. They can review your treatment, adjust the dose, or suggest an alternative approach. Remember that erectile dysfunction can be an early warning sign of cardiovascular disease or diabetes [1][10], so if you're experiencing new or worsening ED, it's worth seeing your GP for a general health check as well as considering treatment options.

Support and Follow-Up at Cured Pharmacy

At Cured Pharmacy, a GPhC-registered online pharmacy (GPhC 9012511), we're committed to safe, effective erectile dysfunction treatment. Our prescribers review every consultation individually, checking for potential drug interactions and ensuring the prescribed dose is appropriate for your circumstances. If you have questions about your treatment or experience any concerning symptoms, our pharmacy team is available to provide advice and support.

We supply Spedra (avanafil) at £20.95, or £16.76 for your first order with code Ednew. All our ED treatments require a clinical consultation, and we never supply prescription medicines without a UK prescriber's approval. This process protects your safety and ensures you receive genuine, licensed medication with clear guidance on correct use.