Vardenafil: uses, side effects, interactions, and more

Vardenafil is a prescription medication that treats erectile dysfunction (ED). It belongs to the same class of drugs as Viagra (sildenafil), Cialis (tadalafil), and Stendra (avanafil). So, what makes vardenafil different from other ED meds? Read on to find out and learn all about vardenafil side effects, drug interactions, and more. 

Vardenafil is the active ingredient in and the generic name for the discontinued drugs, Levitra and Staxyn. It’s a medication approved by the US Food and Drug Administration to treat erectile dysfunction (ED). And while its brand-name versions are no longer on the market, vardenafil is still available today as oral tablets and orally disintegrating tablets (ODT) in varying strengths. (ODT sounds technical, but it’s just the pharmaceutical term for tablets you place on your tongue and wait to dissolve.)

Like Cialis and Viagra, vardenafil is a phosphodiesterase type 5 (PDE5) inhibitor. This type of prescription medication works by blocking the phosphodiesterase-5 (PDE5) enzyme, which breaks down cGMP, the chemical responsible for erections. By inhibiting PDE5, vardenafil allows cGMP to remain active longer, relaxing blood vessels and increasing blood flow to the penis. As a result, the drug can promote stronger, longer-lasting erections. But vardenafil is not a magic pill; it cannot give you an erection if you aren’t aroused. You need to be turned on for it to work effectively.

One reason vardenafil stands out among other ED medications is because of how quickly it starts working. While drug manufacturers recommend taking vardenafil around an hour before having sex, the medication can begin to have effects in as little as 10 minutes. For reference, Cialis typically kicks in about 30 minutes post-consumption while Viagra tends to take up to 60 minutes for most men. 

Vardenafil is approved by the US Food and Drug Administration (FDA) to treat ED, a common condition in which a person assigned male at birth (i.e. typically a man) has difficulty achieving or maintaining an erection strong enough for satisfactory sexual activity. 

Vardenafil is also sometimes prescribed off-label to treat other medical conditions, including:

• Raynaud's phenomenon, a disorder where your blood vessels tighten (constrict) primarily in the fingers and toes, decreasing blood flow

• Pulmonary arterial hypertension, a condition where the blood flow in your lungs is at a higher pressure than normal, leading to the narrowing of blood vessels and increased pressure on your heart 

Vardenafil dosage amounts vary depending on whether you are prescribed the oral tablet (the kind you swallow with water) or the dissolvable tablet (ODT). Vardenafil tablets come in four strengths—2.5 milligrams (mg), 5 mg, 10 mg, and 20 mg—while the dissolvable medication is only available in 10 mg. 

Other factors that can influence the strength prescribed are age, underlying health conditions, and other medications being taken. For most people, the recommended starting dose of vardenafil is 10 mg. Your healthcare provider may adjust your dosage up to 20 mg or down to 5 mg depending on the drug’s effectiveness and your tolerance for side effects.

If you are 65 years of age or older, your healthcare provider may have you start with 5 mg dosage instead. The 5 mg dosage is also recommended for people taking alpha-blockers or those with chronic liver failure. 

People taking certain medications, including CYP3A4 inhibitors like ritonavir or clarithromycin, may need to start with an even lower dosage of 2.5 mg. They may also need to take vardenafil less frequently. Your healthcare provider can give you specific dosage recommendations.

How to take vardenafil

You should take vardenafil around 1 hour before you plan on having sex. You can take vardenafil with or without food, but it may work faster if you take it on an empty stomach. Research has shown that taking vardenafil with food, especially high-fat meals, may delay the drug’s effects by up to 1 hour. Vardenafil tablets can be swallowed with water, while ODT vardenafil should be taken without liquid. Simply place it on your tongue, and let it dissolve.

Whatever dose you are prescribed, you should not take more than one dose of vardenafil per day. If you take certain medications, such as CYP3A4 inhibitors, or have liver problems, your healthcare provider may recommend taking vardenafil less frequently or starting it at a lower dose. 

The most common side effects of vardenafil include:

• Headache

• Flushing

• Runny nose or congestion

• Indigestion

• Dizziness

• Back pain

Although rare, vardenafil can cause more serious side effects, including: 

• Priapism, a prolonged, sometimes painful, erection lasting 4 or more hours that requires emergency treatment

• Sudden loss of vision in one or both eyes

• Sudden decrease or loss of hearing

• Drop in blood pressure (hypotension)

Seek medical attention immediately if you experience any of these concerning side effects. In many cases, they are treatable.

Vardenafil is known to interact with certain medications, including: 

• Nitrates: Nitrates includes both prescription medications like nitroglycerin, which is used to treat chest pain (angina), as well as recreational drugs like amyl nitrites (more popularly known as “poppers”). When taken with nitrates, vardenafil may cause a potentially fatal drop in blood pressure. 

• Guanylate cyclase (GC) stimulators: GC stimulators, such as riociguat (Adempas), also should not be taken with vardenafil. Because both drugs reduce blood pressure, taking them together can lead to a potentially dangerous drop in your body’s pressure levels. 

• CYP3A4 inhibitors: Because these medications interfere with the enzyme CYP3A4 (thus the name) in your liver, they may affect how your liver processes drugs and increase your risk of experiencing side effects on vardenafil. Grapefruit juice may also act on this enzyme and raise vardenafil drug levels. Examples of CYP3A4 inhibitors include ritonavir, cobicistat, indinavir, saquinavir, atazanavir, ketoconazole, itraconazole, clarithromycin, and erythromycin.

• Alpha-blockers: Alpha-blockers, such as doxazosin, terazosin, alfuzosin, and tamsulosin, are used to help lower blood pressure and treat certain prostate conditions, such as benign prostatic hyperplasia (BPH). So, combining them with vardenafil could make your blood pressure too low. 

Before starting vardenafil (or any prescription medication for that matter),talk to your healthcare provider. Share a complete list of any other medications you are taking, including over-the-counter supplements. This way, they can determine whether vardenafil may be safe for you and prescribe an appropriate dosage or recommend another ED treatment. 

Vardenafil is approved for treating ED in adults (those 18 years old and older). Vardenafil is not safe for some people to take, including those who are not healthy enough for sexual activity. If you have any of the following health conditions, you should avoid taking vardenafil as it can increase your risk of experiencing serious side effects:

• Heart problems, including a history of heart disease, heart failure, or a prolonged QT interval (a problem with your heart's electrical system)

• Eye problems, including a history of non-arteritic ischemic optic neuropathy (NAION) or a crowded optic disc

• Allergies to vardenafil or any of the inactive ingredients in the medication

If you’re not sure vardenafil is for you, you’ve got options. For one thing, it’s not the only PDE5 inhibitor on the market. Other PDE5 inhibitors include sildenafil, tadalafil, and avanafil as well as their brand-name versions of Viagra, Cialis, and Stendra, respectively. 

Here’s a look at how vardenafil compares to the other ED medications: 

Some PDE5 inhibitors are also available in alternative formulations. Ro’s Daily Rise Gummies, for example, are fruit-flavored, once-daily gummies that each contain 7 mg of tadalafil. Meanwhile, Ro Sparks is a sublingual ED treatment that combines tadalafil and sildenafil, the active ingredients in Cialis and Viagra, and dissolves under your tongue for fast-acting results. 

Below we answer some frequently asked questions about vardenafil.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

September 16, 2024

Written by

Amelia Willson

Fact checked by

Patricia Weiser, PharmD

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About the medical reviewer

Patricia Weiser, PharmD

Patricia Weiser, PharmD, is a licensed pharmacist, health content writer, and medical reviewer with more than a decade of clinical experience in community and hospital pharmacy.