Vardenafil (Levitra) for erectile dysfunction
Vardenafil is an FDA-approved erectile dysfunction (ED) pill that is taken as needed, about an hour before sex. It comes as a standard tablet and as a tablet that dissolves on the tongue, and the two are not interchangeable. This page covers the label facts, the trial numbers, who should skip it, and how it compares with the other three ED pills.
Information current as of November 10, 2026. Educational only. Confirm everything here with your own clinician before starting, stopping or changing any medication.
At a glance
Drug class
A phosphodiesterase type 5 (PDE5) inhibitor. It extends the blood-flow signal that sexual stimulation starts.
Two forms
A film-coated tablet swallowed with water, and an orally disintegrating tablet (ODT) placed on the tongue. The ODT gives more drug exposure than the 10 mg tablet.
Timing
About 60 minutes before sexual activity, as needed, no more than once a day. Sexual stimulation is required.
Who it is for
Men with ED after a medicine and heart review. Not for anyone on nitrates or riociguat.
Special cautions
Heart rhythm drugs and congenital long QT, certain HIV and antifungal medicines, and liver disease all change the answer.
What it is
How vardenafil works
Sexual stimulation makes the penis release nitric oxide, which raises a messenger called cyclic GMP. Cyclic GMP relaxes the blood vessel muscle so the penis can fill. The enzyme PDE5 breaks cyclic GMP down. Vardenafil blocks that enzyme, so the signal lasts long enough for a firm erection.
Without arousal, the drug has little to act on. It also does not change desire or hormone levels. In the label, a median peak blood level comes about 60 minutes after a dose in the fasted state, and the half-life is roughly 4 to 5 hours for the tablet and 4 to 6 hours for the ODT.
The brand names are Levitra for the film-coated tablet and Staxyn for the ODT. Generic vardenafil tablets and generic ODTs now carry the current labels, and this page draws on those.
Two forms
Tablet or tongue-dissolving tablet
The ODT is not a different strength of the same product. The ODT label says it is not interchangeable with the 10 mg film-coated tablet because it delivers a higher blood exposure. Your prescription names one form, and a switch is a new decision.
- Film-coated tablet: 5, 10 and 20 mg strengths. Swallowed whole.
- ODT: one strength, 10 mg. Placed on the tongue and taken without liquid, right after it comes out of the blister.
- ODT is not for you if you have moderate or severe liver impairment, or take a strong or moderate CYP3A4 inhibitor, or start vardenafil while already on an alpha-blocker. The tablet allows lower doses in some of these cases.
- ODT and phenylketonuria: each ODT carries about 1.4 mg of phenylalanine from aspartame, so the label warns against use in phenylketonuria.
How it is taken
Label dosing, food and alcohol
- Starting dose: 10 mg about 60 minutes before sexual activity, as needed. The tablet label allows a step up to 20 mg or down to 5 mg.
- Frequency: no more than one dose a day.
- Start at 5 mg if you are 65 or older, have moderate liver impairment (the maximum is then 10 mg), or are on a stable alpha-blocker.
- Do not use the tablet in severe liver impairment.
Food
The ODT label says it can be taken with or without food. A high-fat meal did not change total exposure or time to peak for the ODT and lowered the peak level by 35 percent. For the film-coated tablet, high-fat meals lowered the peak by 18 to 50 percent in two food studies. Trials for the ODT were run without regard to meals.
Alcohol
In healthy volunteers, a 20 mg dose did not add to the blood-pressure effect of alcohol over a 4-hour watch, at about 40 mL of pure alcohol for a 70 kg man. That is a narrow test. Alcohol still dulls arousal and can add to dizziness, so keep it light.
The evidence
What the trials showed
- North American fixed-dose trial (tablet): at 3 months, 65, 75 and 80 percent of attempts achieved an erection firm enough for penetration on 5, 10 and 20 mg, against 52 percent on placebo. Keeping the erection through intercourse was 51, 64 and 65 percent versus 32 percent.
- Men with diabetes (Goldstein 2003): 452 men with type 1 or type 2 diabetes took 10 mg, 20 mg or placebo for 12 weeks. Improved erections were reported by 57 percent on 10 mg and 72 percent on 20 mg, versus 13 percent on placebo.
- ODT trials: two placebo-controlled studies with 355 and 331 men, mean age about 62, with about half aged 65 or older. The ODT beat placebo on all three primary measures in both.
These are trial results in particular groups of men, and trials with different populations cannot be lined up against each other. Many men on placebo also report some improvement, so the difference from placebo is the number to watch.
A 2013 network meta-analysis of 118 trials with 31,195 men found that tadalafil and vardenafil were the most effective of the oral PDE5 inhibitors, with no major safety difference among them (Yuan, see sources). It is an indirect comparison and does not predict one man’s result.
Safety
Side effects and warnings
Never with nitrates or riociguat
The label contraindicates nitrates and nitric oxide donors in any form, taken daily or now and then, because the combination can drop blood pressure sharply. It also says a safe interval after a vardenafil dose has not been determined. Riociguat, a pulmonary hypertension drug, is also contraindicated. If you have chest pain after a dose, tell the emergency team what you took and when.
In the tablet trials (2,203 men on vardenafil, 1,199 on placebo), headache occurred in 15 percent versus 4 percent, flushing in 11 versus 1, runny or stuffy nose in 9 versus 3, and indigestion in 4 versus 1. Sinusitis and dizziness were less common. Stopping because of side effects was 3.4 percent versus 1.1 percent on placebo. In the ODT trials, headache was 14.4 percent versus 1.8 percent and flushing 7.6 versus 0.6.
Sudden vision loss
Stop the drug and get care at once. It may be non-arteritic anterior ischemic optic neuropathy (NAION). Observational studies of the whole drug class suggest about a 2-fold higher risk (estimates 2.15 and 2.27), and the label says a causal link is not established. Use extra caution if you have had NAION.
Sudden hearing loss
A sudden drop or loss of hearing, sometimes with ringing or dizziness, has been reported after this class of drugs. Stop the drug and see a physician promptly. The label cannot say whether the drug is the cause.
Erection past 4 hours
Go to an emergency department. The label says untreated priapism can damage penile tissue and cause permanent loss of potency. Take extra care with Peyronie’s disease, sickle cell disease, multiple myeloma or leukemia.
Interactions
Alpha-blockers, heart rhythm drugs and CYP3A4 inhibitors
- Alpha-blockers such as tamsulosin or doxazosin can lower blood pressure enough to cause fainting when combined with a PDE5 inhibitor. Be stable on the alpha-blocker first, start the tablet at 5 mg, and consider spacing the doses.
- QT-prolonging heart rhythm drugs. The label says men with congenital long QT syndrome, or on class IA drugs (quinidine, procainamide) or class III drugs (amiodarone, sotalol), should avoid vardenafil. A 10 mg tablet and an 80 mg dose both lengthened the QTc in a study of 59 healthy men, about as much as the active comparison drug.
- HIV protease inhibitors and some antifungals. Indinavir, saquinavir, atazanavir, clarithromycin, and ketoconazole or itraconazole at 400 mg daily cap the tablet at 2.5 mg in 24 hours. At 200 mg daily, ketoconazole, itraconazole and erythromycin cap it at 5 mg. Ritonavir raised the half-life to 26 hours and has its own strict limit.
- Other PDE5 pills. They share the same targets, and combining them is not recommended.
Heart
Cardiac cautions
Vardenafil lowered supine blood pressure by an average maximum of 7 mmHg systolic and 8 mmHg diastolic in healthy volunteers. For most men that matters little, but the label asks the prescriber to check for underlying heart disease first, and says the drug should not be used in men for whom sexual activity is not recommended for heart reasons.
ED can be an early sign of vascular disease. The Princeton III consensus advises assessing exercise capacity, with stress testing when needed, before treating ED in men with heart disease or risk factors (Nehra, see sources). Our post on cardiac inflammation covers one related lab.
If it does not work
What to try when vardenafil falls short
- Check that there was sexual stimulation, which the label requires.
- Check timing and meals. The label times the dose about 60 minutes before sex, and a high-fat meal lowers the peak blood level.
- Check the form. The ODT and the tablet are different products with different exposure.
- Ask whether a drug interaction or a liver problem changed the dose you actually got.
If those are sorted and it still fails, your physician looks at what the pill cannot fix: diabetes control, sleep apnea, depression, medicines, heart health and testosterone. If labs show low testosterone, see testosterone. Trying a different PDE5 inhibitor is a common next step.
Compared
How vardenafil sits among the four pills
- Sildenafil: about 1 hour before sex. A fatty meal slows it.
- Vardenafil: about 1 hour before, with a tongue-dissolving option and the heart rhythm caution.
- Avanafil: labeled for use as early as 15 minutes before sex.
- Tadalafil: longer acting, with a daily dosing option.
All four share the nitrate rule, the eye and ear warnings and the priapism warning. They differ in timing, food effects and drug-interaction limits.
Summit’s role
What Summit does with vardenafil
Dr. Miranda decides which erectile dysfunction medicine fits you after your history and labs. Summit prescribes tadalafil in Summit Men. It does not dispense Levitra, Staxyn or any other brand-name product, and nothing here promises a prescription.
Summit is telehealth only. The review asks about nitrates, riociguat, heart rhythm drugs and your other prescriptions. See pricing for what is included.
Common questions
Questions people ask
How long before sex should I take vardenafil?
The label says about 60 minutes before sexual activity, as needed, for both the tablet and the ODT, and no more than once a day. It works only with sexual stimulation.
Can I swap the dissolving tablet for the regular tablet?
No. The ODT label says it is not interchangeable with the 10 mg film-coated tablet because it gives higher exposure. A prescriber should make any switch.
Does food or alcohol matter?
The ODT can be taken with or without food. A high-fat meal lowered peak levels by 35 percent for the ODT and by 18 to 50 percent for the tablet. A 20 mg dose did not add to alcohol’s blood-pressure effect in a small healthy-volunteer test.
Can I take it with nitroglycerin?
No. Nitrates and nitric oxide donors are contraindicated, and the label says a safe time interval has not been determined. Tell any emergency team exactly what you took and when.
Who should avoid vardenafil?
Men on nitrates or riociguat, men with congenital long QT syndrome, men on certain heart rhythm drugs, men with severe liver impairment, and men who have been told sex is unsafe for their heart. The ODT has further restrictions.
When is it an emergency?
An erection lasting more than 4 hours, sudden loss of vision in one or both eyes, or sudden hearing loss. Stop the drug and seek care right away.
Sources
Where this comes from
All retrieved November 10, 2026.
- Vardenafil hydrochloride tablets prescribing information. Lannett. DailyMed. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=2782efed-6198-47b9-81ac-3e255e2ab7f6
- Vardenafil hydrochloride orally disintegrating tablets prescribing information. Alembic. DailyMed. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=0ce4eb7b-fa50-441d-ae71-eb33dca27926
- Goldstein I et al. Vardenafil, a new phosphodiesterase type 5 inhibitor, in the treatment of erectile dysfunction in men with diabetes: a multicenter double-blind placebo-controlled fixed-dose study. Diabetes Care 2003. https://pubmed.ncbi.nlm.nih.gov/12610037/
- Yuan J et al. Comparative effectiveness and safety of oral phosphodiesterase type 5 inhibitors for erectile dysfunction: a systematic review and network meta-analysis. Eur Urol 2013. https://pubmed.ncbi.nlm.nih.gov/23395275/
- Nehra A et al. The Princeton III Consensus recommendations for the management of erectile dysfunction and cardiovascular disease. Mayo Clin Proc 2012. https://pubmed.ncbi.nlm.nih.gov/22862865/
- Burnett AL et al. Erectile Dysfunction: AUA Guideline. J Urol 2018. https://pubmed.ncbi.nlm.nih.gov/29746858/
Confirm with your provider. This page is general education, not medical advice, and it does not diagnose or treat anything. Every medication carries risks and is not right for everyone. Medication is prescribed only after a physician evaluation determines it is appropriate for you. Individual results vary and no outcome is guaranteed. Information current as of November 10, 2026.
Next step
Bring your full medicine list
Dr. Miranda reviews your medicines, heart rhythm history and liver health before choosing an ED medicine.