Most men taking vardenafil for erectile dysfunction tolerate it well. But vardenafil side effects do happen, and a small number of them are the kind you shouldn’t shrug off or wait out.
The tricky part is that the common side effects (a flushed face, a stuffy nose, a mild headache) overlap with what a lot of guys would call "no big deal." Meanwhile, the serious ones can look like something else entirely at first. A sudden change in vision. A ringing in the ears. Chest pressure that feels like indigestion.
What I tell patients is this: knowing the difference between an annoying side effect and a warning sign is the whole game. Vardenafil (sold as Levitra and Staxyn) is FDA-approved for erectile dysfunction, and for most patients it works without drama. But if any of the five signs below show up, that’s your cue to stop and call someone.
How Vardenafil Works and Why Side Effects Happen
Vardenafil is a PDE5 inhibitor, the same class as sildenafil (Viagra) and tadalafil (Cialis). It works by relaxing the smooth muscle in penile blood vessels so blood can flow in when you’re aroused.
The catch is that PDE5 isn’t only in the penis. It’s also in the retina, the inner ear, and various blood vessels throughout the body. That’s why vardenafil side effects often show up in places that have nothing to do with sexual function, things like vision, hearing, and blood pressure.
Most reactions are mild and fade within a few hours as the drug clears. According to MedlinePlus, the most common complaints are headache, flushing, runny or stuffy nose, and mild indigestion. If that’s all you’re getting, you’re in the majority.
Warning Sign 1: Chest Pain or Pressure During or After Sex
This is the one that lands people in the ER, and it deserves to be first.
Vardenafil lowers blood pressure modestly. If you’re also taking nitrates (nitroglycerin, isosorbide) for chest pain or heart disease, the combination can drop your pressure dangerously low. The American Heart Association is clear that PDE5 inhibitors and nitrates should never be combined.
Even without nitrates, chest pain during sex can mean your heart is being asked to do more than it can handle. Don’t take more nitroglycerin to "fix it." Call 911. While you’re waiting, it helps to know what to keep on hand. A practical guide to building a heart attack emergency kit at home covers what every household with cardiac risk factors should have ready.
Warning Sign 2: Sudden Vision Changes
A bluish tint to your vision is a known, usually harmless effect of PDE5 inhibitors. It fades.
What’s not harmless: sudden vision loss in one or both eyes. This can signal a condition called NAION (non-arteritic anterior ischemic optic neuropathy), where blood flow to the optic nerve is interrupted. It’s rare, but it’s been reported with all PDE5 inhibitors, and the vision loss can be permanent.
Risk factors that raise the odds:
- Age over 50
- Diabetes
- High blood pressure
- High cholesterol
- A "crowded" optic disc (something your eye doctor would know about)
If your vision suddenly dims, goes dark, or you lose part of your visual field, stop vardenafil and get evaluated the same day.
Warning Sign 3: Sudden Hearing Loss or Ringing
This one catches people off guard. A small number of patients on PDE5 inhibitors have reported sudden hearing loss, sometimes with tinnitus (ringing) or dizziness. It can happen in one ear, often within hours of taking the dose.
The FDA added a warning about this back in 2007. The mechanism isn’t fully understood, but early treatment with steroids may improve the odds of recovery. So don’t wait it out for a few days hoping it resolves. Same-day ENT or urgent care.
Warning Sign 4: An Erection Lasting More Than 4 Hours
Priapism is a urological emergency. If an erection lasts past the four-hour mark, blood trapped in the penis starts to lose oxygen and can damage the tissue permanently, sometimes causing long-term erectile dysfunction worse than what you started with.
Higher-risk patients include men with sickle cell disease, leukemia, multiple myeloma, or anatomic abnormalities of the penis. If you have any of these, your prescriber will determine whether vardenafil is appropriate and at what dose.
If priapism happens: go to the ER. Don’t try to wait it out, and don’t take another pill thinking it’ll reset.
Warning Sign 5: Severe Dizziness or Fainting
A small drop in blood pressure is expected with vardenafil. Severe dizziness, lightheadedness when standing, or actually passing out is not.
This is especially a concern if you’re on alpha-blockers for an enlarged prostate (tamsulosin, alfuzosin, doxazosin). The combination can drop blood pressure sharply. Patients weighing prostate medications often want to understand the interaction landscape first, which is why our comparison of tamsulosin vs alfuzosin for BPH side effects is worth reading if you’re managing both conditions. The general rule is to take the two drugs several hours apart and start vardenafil at the lowest dose.
Other blood pressure medications, recreational poppers (amyl nitrite), and even a couple of glasses of wine can compound the effect.
How Vardenafil Compares to Other ED Drugs on Side Effects
Different PDE5 inhibitors have slightly different side effect profiles. Vardenafil tends to cause fewer visual disturbances than sildenafil but slightly more than tadalafil. Headache rates are roughly similar across the class, though newer options like avanafil were specifically designed for a cleaner profile, something we cover in our breakdown of tadalafil vs avanafil and headache rates.
Duration also matters. If you’re choosing between options based on how long they work, our comparison of sildenafil vs vardenafil and which lasts longer walks through the practical differences.
You can compare prices on generic vardenafil at edrugstore.com if cost is part of the decision.
When to Call Your Doctor vs Go to the ER
Quick triage:
- ER now: chest pain, fainting, vision loss, hearing loss, erection past 4 hours
- Same day: persistent severe headache, prolonged dizziness, irregular heartbeat
- Routine call: mild flushing, stuffy nose, mild headache that fades, occasional indigestion
The Bottom Line on Vardenafil Side Effects
Most men who take vardenafil don’t run into trouble. The drug has a long safety record, and the common vardenafil side effects (flushing, headache, nasal congestion) are predictable and manageable. The five warning signs above are uncommon, but they’re the ones worth memorizing.
Before starting, tell your prescriber every medication you take, including nitrates, alpha-blockers, and any heart medications. Ask your pharmacist whether vardenafil makes sense given your full medication list and medical history. That five-minute conversation prevents the majority of serious vardenafil side effects we see.
This article is for informational purposes only and is not medical advice. Always consult a licensed pharmacist or physician before starting, stopping, or changing any medication.
References
- FDA Levitra (vardenafil) Prescribing Information, official labeling, approved uses, and full safety information.
- MedlinePlus: Vardenafil, NIH patient-facing overview of common and serious side effects.
- FDA Safety Information: PDE5 Inhibitors, FDA warnings on sudden hearing loss and NAION.
- American Heart Association: Cardiac Medications, guidance on nitrate interactions with ED drugs.
Dr Steven Schlosser
Dr. Schlosser graduated from Lafayette College Phi Beta Kappa and attended Georgetown Medical School. He had 4 years of medical residency training at Tufts University in Boston in both Gynecology and Internal Medicine. He has had a spotless medical career for the past 40+ years and is Board Certified. Learn More