Revatio vs. Viagra: What Is the Difference? (2024)

Uses

Revatio is marketed to treat pulmonary arterial hypertension. PAH is a progressive disease that causes high blood pressure in the lungs, making breathing difficult.

Revatio can improve an individual’s ability to exercise without experiencing shortness of breath and prevent the disease from worsening.

Viagra, on the other hand, is marketed to help people maintain a penile erection.Both Revatio and Viagra contain the same active ingredient, sildenafil.

Off-label uses of either Revatio or Viagra are studied under its generic form, sildenafil. Other uses of sildenafil include:

• The prevention of high-altitude pulmonary edema: High-altitude pulmonary edema is when your lungs increase pressure, causing fluid to leak out the blood vessels into the lung tissue.
• Raynaud's phenomenon: Raynaud's phenomenon occurs when there is a restriction of blood flow to your fingers and toes, causing your extremities to turn pale and cold.

Dosage

Viagra is only available as tablets taken by mouth. When using Viagra for ED, the dose is started at 50 mg by mouth one hour before sexual activity and should not be used more than once within 24 hours. If you are 65 or older and have poor liver or kidney function, it is recommended that you start at 25 mg by mouth.

Revatio comes in three different dosage forms: intravenous injection, oral suspension, and oral tablet.

The typical doses of Revatio recommended by the package label for PAH are listed below:

• Ages 18 and up (suspension or tablet): 20 mg by mouth three times a day; if needed, the maximum dose is 80 mg three times daily.
• Ages 18 and up (IV injection): 10 mg IV bolus injection three times a day
• Ages 1 year or older, 20 kilograms (kg) or less: 10 mg by mouth three times a day
• Ages 1 year or older, 20 to 45 kg: 20 mg by mouth three times a day
• Ages 1 year or older, 45 kg or more: 20 mg by mouth three times a day; if needed, the maximum dose is 40 mg three times a day

The dosage may vary among individuals based on age and disease status. Consult your healthcare provider to determine the proper dosage for you.

Revatio vs. Viagra: Main Similarities

Revatio and Viagra require a prescription from your healthcare provider.

Despite Revatio and Viagra being approved for different conditions, they both contain the same active ingredient.Since both medications contain sildenafil, they work the same way.

Revatio and Viagra are classified as phosphodiesterase-5 (PDE5) inhibitors. PDE5 inhibitors work by blocking an enzyme called phosphodiesterase located in various blood vessels throughout the body. When this enzyme is blocked, there is an increase in nitric oxide, causing the blood vessels to widen and relax.

Since Revatio and Viagra work the same, they share similar side effects and drug interactions.

Common side effects experienced in both medications include:

• Flushing
• Headache
• Light-headedness or dizziness when standing up
• Muscle pain (myalgia)
• Stuffy or runny nose
• Upset stomach
  

Medications that may worsen the side effects of Revatio and Viagra are listed below as a few examples:

• Antihypertensives, which treat blood pressure, such as Zestril (lisinopril), Vasotec (enalapril), Diovan (valsartan), Cozaar (llosartan), and Lopressor (metoprolol)
• Azole antifungals, which treat fungal infections, such as Diflucan (fluconazole) and Nizoral (ketoconazole)
  
• Nitrovasodilators, which widen blood vessels, such as Nitrostat (nitroglycerin), Dilatrate-SR (isosorbide dinitrate), and Imdur (isosorbide)

How They Work

Revatio and Viagra work by blocking an enzyme called phosphodiesterase type 5. Blocking PDE5 increases the levels of cyclic guanosine monophosphate (cGMP).

When cGMP rises, nitric oxide increases. High nitric oxide levels cause blood vessels to widen and relax, leading to more blood flow and a decrease in pressure. Both Revatio and Viagra follow the same mechanism; they're just advertised to manage different conditions.

When using Viagra for ED, the medication will block PDE5 in the corpus cavernosum, the spongy tissue filled with blood vessels that surround the penis. Blocking PDE5 results in an increase in blood flow to the penis, which causes an erection.

When using Revatio for PAH, the medication will block PDE5 in the smooth muscles of the lungs. As a result, the blood vessels widen, causing a decrease in pressure in the lungs.

Safety and Precautions

Side Effects

Since Revatio and Viagra work by widening and relaxing your blood vessels, typical side effects such as flushing, headache, or dizziness can occur due to this effect.

Other common side effects include:

• Back pain
• Diarrhea
• Dizziness
• Eyesight changes
• Indigestion
• Limb pain
• Muscle pain
• Rash
• Stuffy nose

With Viagra, if you have a painful erection or an erection that lasts longer than four hours, seek medical attention right away. If left untreated, it may result in permanent problems.

Drug Interactions

Revatio and Viagra are broken down by an enzyme called cytochrome p450 (CYP450). If Revatio or Viagra are combined with a CYP inducer or inhibitor, it can prevent the medication from working or cause an increased risk of side effects.

Common CYP450 inhibitors that increase the risk of side effects of sildenafil include:

• Azole antifungals
• Biaxin (clarithromycin)
• Fluoroquinolone antibiotics, such as Cipro (ciprofloxacin) and Levaquin (levofloxacin)
• Grapefruit juice
• Norvir (ritonavir)

Common CYP450 inducers that may reduce the effect ofsildenafil include:

• Tegretol (carbamazepine)
• Dilantin (phenytoin)
• Rimactane (rifampin)
• Saint-John's-wort

You should not take Revatio or Viagra with nitrate-based medications, like nitroglycerin, because it can lead to a sudden drop in blood pressure.

Who Should Not Take Viagra or Revatio?

Due to Viagra’s dilation effect on the blood vessels and the combination of sexual activity, you should take caution if you have any of these conditions:

• History of heart attack, stroke, or life-threatening arrhythmia within the last six months
• Low or high blood pressure at rest
• Heart failure or coronary artery disease with unstable chest pain

When using Viagra for ED, there have been reports of sudden loss of vision in one or both eyes. This side effect could be an indication that you have non-arteritic anterior ischemic optic neuropathy (NAION), an eye stroke. If you have a history of NAION, consult with your healthcare provider and determine if sildenafil is right for you.

When using Viagra or Revatio, there have been reports of a decrease or loss of hearing. If you experience this symptom, you should stop taking either medication immediately.

How Effective Are They?

Clinical studies were conducted to determine if there was a difference in walking distance among PAH patients who took Revatio vs. patients who didn't.

The results showed that patients on Revatio improved their walking distance after four weeks of treatment and maintained the improvement after that. Based on these results, Revatio was approved for treating PAH to improve exercise ability.

In clinical studies, Viagra was evaluated to determine its effectiveness in helping males with erectile dysfunction achieve and maintain an erection during sexual intercourse. After six months of data collection, 88% of participants reported that Viagra improved their ability to achieve and sustain erections.

How Quickly Do They Work?

Viagra can take about 30 minutes to an hour until you can feel the effects of the medication working. Therefore, Viagra may be taken between 30 minutes to four hours before sexual activity.

Even though it takes an hour for Revatio to start reducing the pressure in your lungs, you might not notice an improvement in your exercise ability until after four weeks of treatment.

Which Should You Take?

Revatio is prescribed for individuals with PAH, whereas Viagra is used for patients who have difficulty maintaining an erection during sexual activity. Both medications contain the same active ingredient but are studied and targeted for different conditions.

Since sildenafil is available in a more affordable generic form, your healthcare provider might prescribe the generic for either PAH or ED.

Summary

Revatio and Viagra both contain the same active ingredient, sildenafil. However, they are used to treat different conditions. Revatio is prescribed for people with pulmonary arterial hypertension (PAH) to help improve their exercise ability and reduce shortness of breath.

Viagra, on the other hand, is used for individuals who have difficulty maintaining an erection during sexual activity. Both medications work by widening blood vessels, which can lower blood pressure in the lungs or increase blood flow to the penis.

Your healthcare provider may prescribe either Revatio or Viagra based on the specific condition you need to manage.

The author would like to recognize and thank Alexya Rosas and Yufeng Zhai for contributing to this article.