Vardenafil (Levitra): how it compares, dosing and side effects

By the Medsmingle Team · Updated 13 November 2026

This is a prescription medicine. Only take it if it has been prescribed for you after a medical assessment, and follow your doctor’s and pharmacist’s instructions.

Vardenafil (brand names Levitra and, as a dissolving tablet, Staxyn) is a PDE5 inhibitor for erectile dysfunction. It works in a similar way to sildenafil and lasts a similar time, but some men respond better to one than another.

How it works and timing

• Helps blood flow into the penis when you’re sexually aroused; it doesn’t increase desire
• Starts working in about 25 to 60 minutes
• Lasts about 4 to 5 hours
• A very high-fat meal may delay the standard tablet

Dosing

Film-coated tablet: usual start 10 mg about 1 hour before sex, adjusted to 5 or 20 mg, no more than once a day. Older men (65+) usually start at 5 mg.

Orally dissolving tablet (10 mg): placed on the tongue to dissolve without water. It isn’t interchangeable mg-for-mg with the standard tablet.

Common side effects

• Headache, flushing
• Stuffy nose
• Indigestion
• Dizziness

Who must avoid it or needs specialist assessment

• Anyone taking nitrates (nitroglycerin, isosorbide mononitrate or dinitrate) or recreational “poppers” (amyl nitrite): the combination can cause a dangerous drop in blood pressure
• Anyone taking riociguat (Adempas) for pulmonary hypertension
• Do not use if your clinician says sexual activity is unsafe. A recent heart attack or stroke requires individual specialist assessment.
• Very low blood pressure, severe liver disease or inherited eye conditions require assessment before treatment; suitability differs between medicines.

Get emergency help (call 911) if you have

• Chest pain, fainting or severe dizziness during or after sex: tell the medical team you took an ED medicine, including the exact medicine and when you last took it
• An erection lasting more than 4 hours (priapism), which can permanently damage the penis
• Sudden loss or decrease of vision in one or both eyes
• Sudden decrease or loss of hearing, with or without ringing or dizziness
• Swelling of the face, lips or throat, or trouble breathing

Extra cautions with vardenafil

• Heart rhythm: vardenafil can slightly prolong the QT interval. Avoid vardenafil if you have congenital long-QT syndrome or take class IA or III antiarrhythmics such as quinidine, procainamide, amiodarone or sotalol; discuss alternatives with your prescriber
• Strong CYP3A4 inhibitors (ketoconazole, ritonavir, clarithromycin) greatly raise levels; lower doses or avoidance are needed
• Alpha-blockers: start at the lowest dose under medical advice

Frequently asked questions

Is vardenafil better than sildenafil?

Studies show similar effectiveness. Some men who don’t respond to one respond to another.

Can I take it with alcohol?

Ask your prescriber about alcohol. Heavy drinking can worsen ED and dizziness; a blanket safe amount cannot be given.

For questions about a prescription or symptoms, speak with your own doctor or pharmacist. For website enquiries, contact our team.

General information only. It isn’t a substitute for advice from your doctor or pharmacist.

Source

MedlinePlus: vardenafil.