Avanafil (Oral)

Avanafil, also known under the brand name of Stendra, is an oral medication prescribed by doctors to male patients who are experiencing erectile dysfunction


What is Avanafil?

Avanafil is an oral medication that is prescribed by doctors for treatment of a condition called erectile dysfunction. Avanafil is also known by the brand name Stendra, which it is marketed and sold under, as well as the name Spedra. Avanafil is a drug known as a phosphodiesterase type 5 enzyme (PDE5) inhibitor and has been approved for use since 2012.

How does Avanafil work?

Avanafil works by inhibiting a specific phosphodiesterase type 5 enzyme found in various body tissues and, specifically, found in the penis. By controlling this enzyme, Avanafil maintains an erection after the penis responds to sexual excitement. Avanafil alone does not cause an erection.

What is erectile dysfunction?

Erection of the penis is caused by blood filling the tissues due to the increased size of the blood vessels that bring blood to this area and a decrease in size of the blood vessels that evacuate the blood in this same place. Sexual stimulation leads to the production and release of nitric oxide in the penis which increases and decreases the blood vessels, leading to an erection. When this enzyme is destroyed, the erection ceases. Avanafil prevents the enzyme from being destroyed, leading to sustained erections.

Erectile dysfunction, also known as impotence, is a condition that is characterized by the inability to develop or maintain an erection of the penis during sexual activity. Erectile dysfunction can lead to poor self-image, cause difficulty in relationships and have psychological consequences as well. It is estimated that 30 million American men are affected by erectile dysfunction.

Avanafil works to achieve an erection during sexual intercourse but does not cure the underlying causes of erectile dysfunction. Patients who are experiencing erectile dysfunction typically have conditions such as cardiovascular disease or diabetes. They may also have neurological problems such as trauma from prostate surgery or others. Erectile dysfunction could be the result of drug therapy or hormonal insufficiencies, as well.

Avanafil is seen as a breakthrough treatment for erectile dysfunction due to its effectiveness, short time to onset and low side effects compared to other treatments. In fact, Avanafil has the fastest time to onset, with an average of 15 to 30 minutes for full absorption.

Conditions Treated

Type of medicine

  • Phosphodiesterase type 5 enzyme inhibitor

Side effects

Patients under treatment with Avanafil may notice certain side effects while taking the drug. These effects should be short in duration and very minor. If you experience any of the following side effects, check with your doctor immediately:

  • Blurred vision
  • Dizziness
  • Headache
  • Nervousness
  • Pounding in the ears
  • Slow or fast heartbeat
  • Arm, back, or jaw pain
  • Bladder pain
  • Bloating or swelling of the face, arms, hands, lower legs, or feet
  • Bloody or cloudy urine
  • Chest pain or discomfort
  • Chest tightness or heaviness
  • Difficult or labored breathing
  • Difficult, burning, or painful urination
  • Fast, irregular, pounding, or racing heartbeat or pulse
  • Frequent urge to urinate
  • Increased erection
  • Lower back or side pain
  • Nausea and vomiting
  • Pain in the groin or genitals
  • Pain, redness, or swelling in the arm or leg
  • Rapid weight gain
  • Sharp back pain just below the ribs
  • Sweating
  • Tightness in the chest
  • Tingling of the hands or feet
  • Unusual tiredness or weakness
  • Unusual weight gain or loss

As your body adjusts to the medication, any side effects you may experience will lessen or go away altogether. Your health care professional may be able to give you instructions on how to lessen or prevent some of the side effects. If you have any of the following side effects for a long period of time or they become severe, contact your doctor:

  • Feeling of warmth
  • Fever
  • Muscle aches
  • Redness of the face, neck, arms, and occasionally, upper chest
  • Sore throat
  • Stuffy or runny nose
  • Acid or sour stomach
  • Belching
  • Body aches or pain
  • Change in color vision
  • Chills
  • Cough
  • Cough producing mucus
  • Diarrhea
  • Difficulty having a bowel movement (stool)
  • Difficulty with moving
  • Ear congestion
  • Heartburn
  • Indigestion
  • Joint pain
  • Loss of appetite
  • Loss of voice
  • Muscle pain or stiffness
  • Pain or tenderness around the eyes and cheekbones
  • Rash
  • Shivering
  • Sneezing
  • Sweating
  • Trouble sleeping
  • Anxiety
  • Bloody nose
  • Bone pain
  • Burning feeling in the chest or stomach
  • Confusion
  • Cool, pale skin
  • Depression
  • Feeling of constant movement of self or surroundings
  • Increased hunger
  • Itching skin
  • Muscle aching or cramping
  • Muscle spasms
  • Nightmares
  • Seizures
  • Sensation of spinning
  • Shakiness
  • Sleepiness or unusual drowsiness
  • Slurred speech
  • Swollen joints
  • Tenderness in the stomach area


Avanafil should be taken exactly as your doctor has prescribed. Do not use more of the drug or use it more often than your healthcare professional has instructed. If too much Avanafil is used, chances for unwanted side effects increase; you will not increase the effectiveness of the drug by changing the dose yourself.

Read all accompanying instructions and information that come packaged with your prescription of Avanafil. Review these instructions each time in case of changes. If you have any questions, consult your healthcare provider or pharmacist right away.

Take Avanafil with or without food, as you prefer, but do not eat grapefruit or drink grapefruit juice while you are using this medication.

Different patients will be prescribed different doses of Avanafil as ordered by their health care provider. Follow all instructions imparted by your doctor found on the label of your prescription. The following information is on the average dose of Avanafil; yours may be different.

Avanafil is sold in 50 milligrams, 100 milligram and 200 milligram tablets. On average, adults are instructed to take one 100 milligram dose no more than once per day, ideally 15 minutes before having sexual intercourse. Your dose amount may be adjusted as needed but typically will not exceed 200 milligrams once per day.


Inform your healthcare provider if you are allergic to Avanafil or any other drug prior to beginning treatment. If you are allergic to any dyes, preservatives, foods or animals, it is also best to inform your doctor before beginning the use of Avanafil to treat erectile dysfunction.

It is of critical importance that you disclose your full medical history as well as details of any drugs you are currently taking or have taken in the recent past before you begin to use Avanafil or any other drug. Include all prescription as well as non-prescription medications you may be taking and details of any holistic, vitamin or herbal supplements or treatments you are currently taking or have taken.

Avanafil is indicated in children for any reason and no information is available on Avanafil with regard to use in pregnant women or women who are breastfeeding. As there is simply no indication for this drug for any use in these groups, no studies have been done as to effects or safety. No studies have been done to date that demonstrate any geriatric-specific problems for this age group that would limit the effectiveness or cause any safety risks, however, medications commonly prescribed to this age group may interact with Avanafil and cause unwanted side effects. Use of Avanafil in geriatric patients is up to you and your doctor.

Use of Avanafil, while you are being treated with the following medications, is not recommended. Your health care provider may decline to prescribe Avanafil for you if you are on the following medications:

  • Amyl Nitrite
  • Erythrityl Tetranitrate
  • Isosorbide Dinitrate
  • Isosorbide Mononitrate
  • Nitroglycerin
  • Pentaerythritol Tetranitrate
  • Propatyl Nitrate
  • Riociguat

Use of Avanafil with the following drugs is typically not recommended but may be required in some patients. It is up to your doctor to determine if Avanafil is appropriate for your current medical situation including the use of the following drugs:

  • Atazanavir
  • Boceprevir
  • Clarithromycin
  • Cobicistat
  • Conivaptan
  • Darunavir
  • Efavirenz
  • Etravirine
  • Indinavir
  • Itraconazole
  • Ketoconazole
  • Lopinavir
  • Nefazodone
  • Nelfinavir
  • Nevirapine
  • Posaconazole
  • Ritonavir
  • Saquinavir
  • Telaprevir
  • Telithromycin
  • Voriconazole

The following drugs may give patients who take Avanafil side effects that are previously not experienced or worse than normal. Use of Avanafil with these medicines should be cautious:

  • Doxazosin
  • Erythromycin
  • Tamsulosin

Avanafil use with alcohol consumption can increase certain side effects of the drug. Avoid drinking more than three alcoholic beverages while taking Avanafil. Grapefruit and grapefruit juice may interact with this drug and cause unwanted side effects and should be avoided. Avanafil will not protect you from sexually transmitted diseases such as HIV and AIDS.

Patients who have been diagnosed with other medical problems may experience increased symptoms or side effects when taking Avanafil. Make sure you inform your health care professional if you have any of the following conditions:

  • Abnormal penis, including curved penis and birth defects of the penis
  • Age greater than 50 years
  • Coronary artery disease
  • Crowded disc or low cup to disc ratio in the eye (an eye disorder)
  • Diabetes
  • Heart disease
  • Hyperlipidemia (high fats in the blood)
  • Hypertension (high blood pressure)
  • Non-arteritic anterior ischemic optic neuropathy or NAION (serious eye condition)
  • Smoking
  • Angina (severe chest pain), unstable
  • Arrhythmia (irregular heartbeat, within the last 6 months)
  • Blood vessel problems (eg, aortic stenosis, idiopathic subaortic stenosis)
  • Congestive heart failure
  • Heart attack (within the last 6 months)
  • Hypertension (high blood pressure), uncontrolled
  • Hypotension (low blood pressure)
  • Retinal disorders (eye problem)
  • Retinitis pigmentosa (an inherited eye disorder)
  • Stroke (within the last 6 months)
  • Bleeding disorders
  • Stomach ulcers
  • Leukemia (blood-related cancer)
  • Multiple myelomas (blood-related cancer)
  • Sickle-cell anemia (blood disorder)


Stop using Avanafil immediately and summon emergency medical help if you have sudden vision loss while taking this drug. This could be a sign of non-arteritic anterior ischemic optic neuropathy, a condition that may lead to blindness. Patients who use tobacco products are more likely to experience this dangerous side effect.

Rare cases of sudden hearing loss, accompanied by ringing in the ears and dizziness, have been reported with use of Avanafil. If changes in hearing occur, stop use of Avanafil and seek medical attention immediately.

If, while engaging in sexual intercourse, you become nauseated, dizzy or have numbness, tingling or pain in your arms, jaw, neck or chest, stop right away and call your doctor immediately as you could be having a serious side effect of Avanafil.

Use of Avanafil in patients with pre-existing heart disease may cause the following:

  • Chest pain
  • Heart attack
  • Death
  • Stroke
  • Palpitations
  • Increased heart rate

Patients experiencing these symptoms should stop activity and seek immediate medical attention.

Do not use Avanafil if you have also been prescribed nitrate medicine for treatment of angina (chest pain) or high blood pressure. Nitrate medicines include nitroglycerin, isosorbide, Imdur, Nitro-Bid, Nitro-Dur, Nitrol Ointment, Nitrolingual Spray, Nitrostat and Transderm Nitrol. Some illegal "street"drugs known as poppers also contain nitrates. Avanafil should not be used if you also use riociguat (Adempas).

If you take too much Avanafil or take it with other phosphodiesterase type 5 enzyme (PDE5) inhibitors such as sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra), your chances for unwanted and potentially dangerous side effects will be greater.

Tell your doctor if you are currently experiencing any heart problems or if you have experienced or been diagnosed with heart problems in the past. Avanafil can cause serious health risks in patients who have heart problems.

If you experience a long (4 hours) or painful erection, contact your doctor immediately as this condition could require prompt medical treatment to prevent serious and permanent damage to the penis.

Patients who are currently taking medication for high blood pressure could experience periods of low blood pressure with use of Avanafil. Call your doctor immediately if you have more than one of the following symptoms:

  • Blurred vision
  • Confusion
  • Dizziness
  • Faintness or lightheadedness when rising from sitting or lying position
  • Sweating
  • Unusual fatigue or weakness

Do not drink more than three glasses of wine or three shots of whiskey when taking Avanafil, as excess amounts of alcohol taken with this drug can increase your chances of getting a headache, dizziness or increased heart rate or lowered blood pressure.

Avanafil does nothing to protect you against sexually transmitted diseases including HIV or AIDS. Protective methods should be used during sexual contact to prevent disease transmission. If you have any questions about this, contact your doctor.

Use of other medications while on Avanafil should be discussed with your doctor; this includes any prescription or non-prescription medication, vitamins, herbs or holistic supplements. Disclose your full medical and medical treatment history to your health care professional so that the determination can be made if Avanafil is safe and effective for you.


Store your prescription of Avanafil in the original packaging, away from sight and reach of children or pets. Avanafil can be stored at room temperature away from heat, moisture, and direct light sources. Do not allow this medication to freeze. Unused or expired Avanafil should be disposed of properly. Consult your healthcare provider or your pharmacist on the safe way to dispose of unused or unwanted Avanafil.


Avanafil is a medication known as a phosphodiesterase type 5 enzyme or PDE5 inhibitor, which is prescribed in tablet form to men experiencing erectile dysfunction. Erectile dysfunction is characterized as the penis not becoming erect during sexual arousal or the inability to maintain an erection during sexual activity. Erectile dysfunction can affect a person's life negatively by giving them poor self-imagine and psychological issues and creating difficulty in personal relationships.

Avanafil is also known as Stendra and is available in strengths of 50 milligrams, 100 milligrams and 200 milligrams. Avanafil is known to have the fastest onset of action, with average times of 15 to 30 minutes, over other drugs in this class. Prescribed amounts vary by patient and your doctor's instructions should be followed at all times. Use of this medicine should occur approximately 15 minutes before sexual activity for maximum effectiveness.

Avanafil is intended for use in males only and has no indications for women or children. Use of Avanafil in geriatric patients is cautioned as it could interact with drug therapies and medical conditions common to this age group. Full medical and drug therapy history should be disclosed to your health care provider prior to being prescribed this or other drug therapies.

Patients should not consume more than three alcoholic beverages when using Avanafil nor should smokers be prescribed this drug as they are at a higher risk for a dangerous condition known as non-arteritic anterior ischemic optic neuropathy, a condition that may lead to blindness. Use of Avanafil with nitroglycerine therapy drugs and street drugs known to contain nitrates or nitrites is forbidden for safety reasons. Use of Avanafil with other phosphodiesterase type 5 enzyme or PDE5 inhibitors such as Viagara, Cialis or Levitra is also discouraged as this could lead to overdose side-effects.

Patients who experience prolonged or painful erections lasting four hours or more should immediately contact their doctor as this condition may require medical treatment for the prevention of serious and permanent physical damage. Read all informational materials provided with your prescription to make sure you are using Avanafil safely and effectively.

Store Avanafil at room temperature away from direct light, heat sources and moisture and do not allow the medication to freeze. Keep out of sight and reach of children and pets.

Last Reviewed:
December 24, 2017
Last Updated:
April 04, 2018