Vardenafil (Levitra): How It Works, Dosing, Side Effects and Safety

Vardenafil, sold as Levitra and in an orally disintegrating form as Staxyn, is the least talked-about of the main erectile dysfunction medications. It sits between sildenafil and tadalafil in character: similar timing to sildenafil, but more selective for its target enzyme, which changes its side effect profile slightly. For some men that combination works better than either of the more famous options. This guide covers how it works, how it is dosed, what to expect, and the safety rules that are not optional.

• How vardenafil works
• How it compares with sildenafil and tadalafil
• Dosing and timing
• How well does it work?
• Side effects
• Who should not take it
• Drug interactions
• Who vardenafil suits
• Frequently asked questions

How Vardenafil Works

Sexual stimulation causes the release of nitric oxide in the penis, which raises levels of cyclic guanosine monophosphate (cGMP). cGMP relaxes the smooth muscle lining the penile arteries, blood flows into the erectile tissue, and an erection results. An enzyme called phosphodiesterase type 5 (PDE5) breaks cGMP down.

Vardenafil blocks PDE5, so cGMP lasts longer and the natural erectile response is amplified. Two consequences are worth stating plainly. It does nothing without sexual arousal, because the nitric oxide signal has to come first. And because it mildly relaxes blood vessels elsewhere in the body too, it lowers blood pressure slightly, which is the basis of every serious interaction listed below.

How It Compares With Sildenafil and Tadalafil

	Vardenafil (Levitra)	Sildenafil (Viagra)	Tadalafil (Cialis)
Onset	25 to 60 minutes	30 to 60 minutes	30 to 120 minutes
Duration	About 4 to 8 hours	About 4 to 6 hours	Up to 36 hours
Food effect	Reduced by a high-fat meal	Reduced by a high-fat meal	Largely unaffected
Daily option	No	No	Yes, at low dose
Visual side effects	Less common	More common	Uncommon
Back and muscle ache	Uncommon	Uncommon	More common

The practical difference: vardenafil is more selective for PDE5 over PDE6, the related enzyme in the retina, so the blue-tinged vision some men get on sildenafil is less likely. It does not share tadalafil’s long window, so it needs more planning, but it also avoids tadalafil’s characteristic back and muscle ache. Our guides to sildenafil and tadalafil cover the alternatives in full.

Dosing and Timing

Vardenafil tablets come in 2.5 mg, 5 mg, 10 mg and 20 mg. The usual starting dose is 10 mg taken roughly one hour before sexual activity, adjusted up or down based on response and tolerability, with a maximum of one dose in 24 hours. Lower starting doses are typical for men over 65, men with liver impairment, and men taking certain interacting medications.

Three practical rules:

• Avoid a heavy, high-fat meal beforehand, which delays and blunts absorption. A light meal is fine.
• Give it a fair trial. Guidelines suggest trying a given dose several times before concluding it does not work, since expectation and situation affect early attempts substantially.
• The orally disintegrating tablet is not interchangeable with the regular one milligram for milligram; it is dosed differently and taken without water.

How Well Does It Work?

Vardenafil performs comparably to the other PDE5 inhibitors in clinical trials, with substantial improvement in erectile function scores versus placebo across a range of causes, including men with diabetes and men after prostate surgery, groups that are often harder to treat. Roughly two thirds to three quarters of men respond, which also means a meaningful minority do not. Non-response often reflects the underlying cause: significant nerve damage, severe vascular disease, or low testosterone that has not been addressed. If one PDE5 inhibitor fails, switching to another sometimes works, and options beyond the class exist, including injection therapy and vacuum devices.

Side Effects

Most are mild and stem from vasodilation. Headache is the most common, reported by roughly one in ten men. Flushing, a sensation of warmth or redness in the face and neck, affects around one in twenty. Nasal congestion affects a few percent, and indigestion, dizziness and mild back or muscle ache are each reported by a small percentage. Temporary colour-vision changes are possible but less common than with sildenafil.

Side effects tend to lessen with repeated use, and a dose reduction usually resolves a persistent one.

Seek immediate medical care for an erection lasting more than four hours (priapism, which can cause permanent damage), sudden vision loss in one or both eyes, sudden hearing loss or ringing, or chest pain, severe dizziness or fainting after a dose. If you need emergency care, tell the clinician which medication you took and when, because it determines what they can safely give you.

Who Should Not Take It

• Anyone taking nitrates, including nitroglycerin in any form, isosorbide, and recreational nitrite “poppers”. The combination can cause a life-threatening drop in blood pressure. This is absolute.
• Anyone taking riociguat or a similar guanylate cyclase stimulator.
• Men with severe cardiovascular disease where sexual activity itself is inadvisable: unstable angina, recent heart attack or stroke, severe heart failure.
• Men with congenital long QT syndrome or taking class IA or III antiarrhythmics such as quinidine, procainamide, amiodarone or sotalol. Vardenafil can prolong the QT interval, which is a specific caution for this drug that does not apply equally across the class.
• Men with a history of NAION (sudden vision loss), severe liver impairment, or requiring dialysis.
• Men with uncontrolled high or very low blood pressure, until it is managed.

Drug Interactions

• Alpha-blockers (tamsulosin, doxazosin, alfuzosin) for prostate symptoms: both lower blood pressure, so doses are separated and started low.
• CYP3A4 inhibitors that slow its breakdown: ketoconazole, itraconazole, clarithromycin, erythromycin, and HIV protease inhibitors such as ritonavir and indinavir. These require significant dose reductions, and with some the drug is avoided entirely.
• QT-prolonging drugs, including certain antiarrhythmics and some antipsychotics and antibiotics.
• Other antihypertensives: generally compatible, but the additive blood-pressure effect is real.
• Grapefruit juice, which acts on the same enzyme pathway.
• Alcohol, which is not a formal interaction but compounds the blood-pressure effect and independently worsens erections.

Bring a full list of everything you take, including supplements, to the appointment. Our guide to blood pressure medication and erectile dysfunction covers the overlap between treating one and causing the other.

Who Vardenafil Suits

It tends to suit men who found sildenafil effective but disliked the visual side effects, men who want a defined window rather than tadalafil’s 36 hours, and men with diabetes, where it has a solid evidence base. It is a poorer fit for men who want spontaneity across a weekend, for whom daily tadalafil is usually the better answer, and it is ruled out entirely for men with QT-interval concerns.

It contains Tribulus terrestris, saw palmetto and maca root, contains no prescription medication of any kind, does not hold a Natural Product Number from Health Canada, and no claims are made that it treats erectile dysfunction. Anything sold without a prescription that produces vardenafil-like effects should be treated as suspect, for the reasons set out in our guide to the safety and risks of boner pills.

How long does vardenafil stay in your system?

Its half-life is roughly four to five hours, so it is largely cleared within about a day, though the useful window for sexual activity is four to eight hours.

Is vardenafil stronger than sildenafil?

It is more potent milligram for milligram, which is why the doses are lower, but that does not make it more effective. Trials show broadly comparable results across the class.

Can I take vardenafil every day?

No. It is licensed for use as needed, at most once in 24 hours. Only tadalafil has an approved low-dose daily option.

Does it work after prostate surgery?

It has been studied in men after nerve-sparing prostatectomy with meaningful improvement for many, though results depend heavily on whether the nerves were preserved. This is a conversation for your urologist.

Why did my doctor choose vardenafil over Viagra?

Common reasons include troublesome visual side effects on sildenafil, a poor response to it, or a preference based on your other medications and timing needs.

Is generic vardenafil the same?

Generic vardenafil from a licensed pharmacy contains the same active ingredient and must meet the same standards. Product bought from an unverified website is a different question entirely, and counterfeits are common.

References

• Keating GM, Scott LJ. Vardenafil: a review of its use in erectile dysfunction. Drugs. 2003. PubMed
• Huang SA, Lie JD. Phosphodiesterase-5 (PDE5) inhibitors in the management of erectile dysfunction. Pharmacy and Therapeutics. 2013. PMC3776492
• Mayo Clinic. Erectile dysfunction: diagnosis and treatment. mayoclinic.org

Important Health Information

This article is general information and is not a substitute for professional medical advice, diagnosis or treatment. Speak to a doctor or pharmacist before starting any supplement, especially if you have a medical condition or take medication.

About ErecteMax

ErecteMax Herbal Supplement Capsules for Men contain maca root (85 mg), saw palmetto (45 mg) and tribulus terrestris (45 mg) per capsule. ErecteMax is not licensed by Health Canada, has no NPN and makes no health claims. See the product page for the full label.