8 Avanafil Side Effects You Should Know About

If you have erectile dysfunction (ED), you may be prescribed a medication like avanafil (Stendra) to help achieve or maintain erections. Avanafil belongs to the same class — phosphodiesterase-5 (PDE5) inhibitors — as medications like sildenafil (Viagra) and tadalafil (Cialis). But it may be the preferred option for some men since it kicks in the fastest.

Avanafil works by improving blood flow to the penis for an erection. However, the way it works can also cause side effects in other areas of your body. Headache, flushing, and nasal congestion are all possible after taking it. Although rare, serious side effects can happen, too. 

Let’s discuss a few common and serious avanafil side effects and how to manage them.

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1. Headache

Headaches are one of the most common side effects of PDE5 inhibitors, including avanafil. And they’re more likely to happen if you’re taking higher doses.

Avanafil primarily works by widening blood vessels in the penis. But it has the potential to affect blood vessels in your brain, too. This is what can may cause headaches, including migraines and cluster headaches.

These headaches usually resolve on their own. But if they become bothersome, speak with your healthcare provider. They may tell you to take an over-the-counter (OTC) pain reliever as needed. Usually, this includes acetaminophen (Tylenol) or ibuprofen (Advil, Motrin). They may also discuss lowering your dose or switching to another medication. 

2. Flushing

Some people taking avanafil report skin flushing after taking a dose. Similar to headaches, avanafil can cause blood vessels to widen in other parts of your body. And having more blood near the skin’s surface can cause it to look red or feel warm to the touch.

Flushing usually goes away on its own. If it becomes bothersome, speak with your healthcare provider. They may have you try taking a lower dose. 

3. Nasal congestion

Although it’s not all that common, nasal congestion can occur after taking avanafil. This is due to the widening of blood vessels in your sinuses. While this side effect can be annoying, remember that it’s usually temporary. 

Sometimes, nasal congestion may last for a few hours after avanafil’s effects have worn off. In this case, you can give home remedies a try for some relief. There are also quite a few OTC decongestants that may help. 

Keep in mind that decongestants reduce blood flow, which may affect an erection. So it’s best to take them after you need avanafil to work. And they may interact with other medications and health conditions, too. Ask your healthcare provider about options that are safe for you. If nasal congestion continues to be a problem, they may consider lowering your avanafil dose.

4. Common cold

Similarly, you may feel like you have common cold symptoms after taking avanafil. In addition to a stuffy nose and headache, you may also experience a sore throat. This has been reported most frequently with higher avanafil doses. 

As with nasal congestion and headaches, there are home remedies and OTC products that may help soothe a sore throat. Talk to your healthcare provider about ways to best manage this side effect. If it becomes bothersome, they may lower your dose.

5. Back pain

Some people taking avanafil have reported back pain, most often with lower doses. We don’t actually know why this happens with PDE5 inhibitors. But it appears to be short lasting and resolves on its own. 

If your back pain becomes persistent, let your healthcare provider know. They can determine if it’s caused by avanafil or something else, and how to manage it.

6. Prolonged erection

Avanafil works by increasing blood flow to your penis. But sometimes the blood can’t drain back out properly. This can cause an erection that lasts longer than it should. Although rare, you may have an erection lasting longer than 4 hours (called priapism). 

Priapism can be very painful. And if left untreated, it causes permanent damage to your penis. This is considered a medical emergency. Seek immediate medical attention if this happens. 

7. Vision problems

PDE5 inhibitors, including avanafil, can cause vision problems. This includes a rare but serious condition called non-arteritic anterior ischemic optic neuropathy (NAION). NAION occurs when blood flow to the optic nerve is interrupted. That prevents the nerve from communicating between your eyes and brain.

In general, NAION is estimated to affect less than 12 out every 100,000 men, ages 50 and older. All PDE5 inhibitors can double your risk of developing NAION, but it’s still very rare. 

To be safe, notify your healthcare provider if you notice any changes in your vision. That includes blurred or double vision. Seek immediate medical attention if you lose vision in one or both of your eyes.

8. Cardiovascular risks

Avanafil can cause a drop in blood pressure. And the greatest change in blood pressure typically happens an hour after taking a dose. This effect may cause problems if you have underlying heart disease, especially when it’s combined with sexual activity.

Because of this, your healthcare provider should know your full health history before prescribing avanafil. For example, avanafil may not be safe to take if you’ve had a heart attack or stroke in the past. They can decide the safest option for your specific situation and risk factors.

If you develop any new or worsening chest pain or shortness of breath after taking avanafil, get immediate medical attention. This could be a sign of something serious, like a heart attack.

What’s more, PDE5 inhibitors can interact with medications that treat high blood pressure and chest pain. Some combinations can cause dangerously low blood pressure. These should be avoided altogether. Your healthcare provider can determine which interactions might affect you and how to manage them.

When should I contact my healthcare provider about side effects from avanafil?

If any avanafil side effects become bothersome, that’s a good time to contact your healthcare provider. If necessary, they can recommend a dosage adjustment or treatment change. 

Sometimes, medication side effects can be worsened due to an interaction. Your healthcare provider can review your medication list to identify any that might be contributing to the problem.

As discussed above, there are certain situations that require immediate medical attention. Examples of these include:

• An erection that’s painful or lasts longer than 4 hours

• Loss of vision in one or both eyes

• New or worsening chest pain or shortness of breath

But if any side effects feel severe or life-threatening, it’s best to get medical attention right away.

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Written by:

Brian Leonard, PharmD, BCACP, BCGP

Brian Leonard earned his doctorate in pharmacy from the University of Florida College of Pharmacy and is board certified in Ambulatory Care and Geriatric Pharmacy.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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