If a clinician suggested vardenafil, the name Levitra may be the one you remember. Vardenafil works the way sildenafil does, but its label has a few differences that explain why it suits some people and not others: a heart-rhythm warning, a different food effect, and stricter cautions around certain heart medicines.
Both drugs block PDE5, need sexual stimulation and share warnings about nitrates, priapism, sudden vision loss and sudden hearing loss. The vardenafil label adds a QT-interval section and tells people with congenital QT prolongation, or those taking class IA or III antiarrhythmics, to avoid it. Which drug a given person should use is a clinical decision that depends on heart health and the full medicine list.
Most comparisons of ED pills are built around marketing: faster, longer, stronger. The prescribing information is less dramatic and more useful. It shows where the drugs match, where they diverge, and which differences could matter for you. Our broader piece, PDE5 inhibitors compared, covers all three; this one stays with sildenafil and vardenafil.
A note on the name: Levitra is now mostly a generic story
When we searched DailyMed on October 30, 2026, the Levitra brand entries were older repackager labels (dated 2010 and 2011), while current vardenafil hydrochloride tablet labels were from 2026 and were written for the generic product. The Staxyn orally disintegrating tablet label we found was also dated 2012. We could not confirm from those pages whether the brand is still marketed, so this article uses the generic vardenafil label as the current reference and treats “Levitra” as the name patients recognize. If you are comparing a pharmacy bottle with this page, ask the pharmacist to confirm the product and read the patient leaflet that came with it.
Label comparison
| Feature | Viagra (sildenafil) | Vardenafil (generic Levitra) |
|---|---|---|
| Timing in the label | Taken as needed, about 1 hour before sexual activity; may be taken from 30 minutes to 4 hours before | Taken about 60 minutes before sexual activity |
| Half-life (terminal) | About 4 hours for sildenafil and its active metabolite | About 4 to 5 hours for vardenafil and its main metabolite |
| Food | May be taken with or without food; after a high-fat meal absorption is slower, with a mean 60-minute delay in peak and 29% lower peak level | May be taken with or without food; label food-effect studies show high-fat meals reduced peak concentration by 18% to 50% |
| Heart-rhythm section | No dedicated QT section among the main warnings reviewed | Section 5.7: congenital or acquired QT prolongation; avoid with class IA or III antiarrhythmics or congenital QT prolongation |
| Alpha-blockers | Caution; blood pressure may drop | Caution; start at the lowest dose and only when stable on the alpha-blocker; label suggests considering a time interval between doses |
| Nitrates | Contraindicated | Contraindicated, including nitric oxide donors |
| Older adults | Label suggests considering a lower starting dose in people over 65 | Label suggests considering a lower starting dose at 65 or older; exposure was 34% (peak) and 52% (AUC) higher in older men |
| Other formats | Tablets | Tablets; an orally disintegrating tablet existed as Staxyn |
The dose and timing items are label descriptions, not instructions. Your prescriber chooses strength and timing for your situation.
The QT warning: what it means and who it affects
The vardenafil label describes a study in 59 healthy men in which a 10 mg dose and a supratherapeutic 80 mg dose produced increases in QTc interval similar to the control drug moxifloxacin, and a postmarketing study that found an additive QT effect when vardenafil was combined with a drug of comparable QT effect. The label’s practical conclusion: people with congenital QT prolongation, or those on class IA (such as quinidine, procainamide) or class III (such as amiodarone, sotalol) antiarrhythmics, should avoid vardenafil.
For most men with no heart-rhythm history and no such medicines, the QT section is background. For men with atrial fibrillation on an antiarrhythmic, a family history of sudden death, or an unexplained fainting history, it can change the choice. If you have any of these, say so when the drug is first discussed. The same reasoning appears in our guide to citalopram and QT risk, a reminder that several unrelated medicines can add to the same rhythm effect.
Side effects: very similar, with a few different headliners
The vardenafil label lists the most common adverse reactions (2% or more of patients) as headache, flushing, nasal congestion, dyspepsia, sinusitis, flu syndrome, dizziness, increased creatine kinase, nausea and back pain. The Viagra label lists headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash. The visual symptom stands out for sildenafil: the Viagra label describes mild to moderate, transient abnormal vision, mainly a color tinge, with increased sensitivity to light or blurred vision.
That list is why “Levitra side effects” and “Viagra side effects” read alike. Our dedicated pages on sildenafil side effects and the PDE5 warning signs for vision, hearing and priapism cover what is routine and what is urgent.
Stop the medicine and seek care for an erection lasting more than 4 hours, sudden loss of vision in one or both eyes, or sudden decrease or loss of hearing. The vardenafil label cites an observational study suggesting an approximate two-fold higher risk of NAION (a rare optic nerve condition) when a PDE5 inhibitor was used shortly before onset, with a risk estimate of 2.15 (95% CI 1.06 to 4.34). It also notes that the numbers do not settle causation.
Is one stronger or longer lasting?
Not in a way the labels allow us to state. Vardenafil and sildenafil have similar half-lives in their labels (4 to 5 versus about 4 hours), and neither label presents a head-to-head trial. Tadalafil is the outlier, with a label half-life of 17.5 hours and a statement that it improved erectile function compared with placebo for up to 36 hours; see how long Cialis lasts. Individual response to sildenafil and vardenafil varies, and the reasons a prescriber might move from one to the other are usually practical: a food pattern, a side effect, a drug interaction, or a response that was not good enough on the first drug.
Why a clinician might choose vardenafil
- A person had a specific side effect on sildenafil, such as the color-tinged vision, and wants to try a different molecule.
- Food habits: both labels allow food, but a person who usually takes the medicine after a heavy meal may want a prescriber’s view of the label’s food-effect data.
- Cost or formulary: generic vardenafil is covered differently by different plans. That is a plan question, not a medical one.
Why a clinician might avoid it
- Known long QT syndrome or antiarrhythmic use (class IA or III).
- Certain medicines that raise vardenafil levels. The label sets a sharply lower maximum single dose, with a long minimum interval, when vardenafil is combined with indinavir or ritonavir, which shows how strongly interacting drugs can change exposure; the prescriber and pharmacist handle these.
- Alpha-blocker therapy that is not stable.
Alcohol, food and the myths around them
People often ask whether one drug is safer with a drink. The vardenafil label reports that in healthy volunteers, vardenafil 20 mg did not potentiate the hypotensive effects of alcohol (0.5 g/kg, about 40 mL of absolute alcohol in a 70 kg person) over a 4-hour observation period, and that alcohol and vardenafil plasma levels were not altered by simultaneous dosing. The Cialis label takes a more cautious tone, advising that substantial alcohol consumption (5 units or more) with tadalafil can increase orthostatic signs. Those are results from different studies in different settings, and none is a license to drink heavily; dizziness from alcohol and a PDE5 inhibitor can add up on its own.
Food is the other recurring question. The vardenafil label allows the tablets with or without food but reports that high-fat meals reduced peak concentrations by 18% to 50% in food-effect studies, while the Viagra label reports a mean 60-minute delay and 29% lower peak after a high-fat meal. The consistent message across both is that a heavy meal can blunt or delay the effect, and that you should ask about timing rather than guess.
Interactions that deserve a pharmacist’s eye
Vardenafil is metabolized mainly by the liver enzyme CYP3A4, which is why strong inhibitors raise its levels. The label reports that ritonavir prolonged the half-life of vardenafil to 26 hours and recommends a sharply lower maximum single dose, with a long minimum interval, when it is combined with ritonavir or indinavir. Antifungals and some antibiotics can also change levels. You do not need to memorize these. You do need to tell whoever prescribes it about every other medicine, including HIV, antifungal and heart-rhythm drugs, because the safe plan changes with them.
Checklist before the appointment
- List every medicine, including heart-rhythm drugs, HIV medicines, antifungals, antibiotics and prostate medicines.
- Note any history of fainting, palpitations or a family history of sudden death.
- Say whether you use nitroglycerin or any form of nitrate, including recreational nitrites.
- Mention eye disease, hearing changes or conditions that make priapism more likely.
- Ask what happens if the first pill does not work well, instead of trying a second one yourself.
Combining pills is a recurring risk in this area: see can you take Viagra and Cialis together for the labels’ position on stacking PDE5 inhibitors, which applies to vardenafil in the same way.
Sources
Evidence checked October 30, 2026. General information only; it does not recommend a particular ED medicine.