Drug interactions are an essential part of deciding whether vardenafil can be prescribed for erectile dysfunction. The most dangerous combinations include organic nitrates and the guanylate-cyclase stimulator riociguat, which are contraindicated because of potentially severe blood-pressure lowering. Additional interactions require careful review rather than a generic “avoid everything” rule.
Vardenafil is metabolized chiefly through CYP3A4. Some inhibitors can greatly increase exposure and require drug-specific prescribing limitations; alpha-blockers and antihypertensive drugs can increase the risk of symptomatic hypotension. Unlike some other PDE5 inhibitor discussions, vardenafil also requires particular attention to QT prolongation and use of certain heart-rhythm medications.
This page is the class-by-class interaction hub. The high-risk nitrate combination has a dedicated explanation at vardenafil and nitrates; alcohol and food have separate guides at alcohol and meals. The exact prescriber and dispensing label control clinical decisions.
The severity of an interaction depends on mechanism, co-medication, strength, formulation, other illnesses, and the full regimen. Some pairs are expressly contraindicated, while others require altered prescribing or avoidance depending on the product. The table is a screening map, not a set of do-it-yourself adjustment instructions.
Patients should bring an accurate list including emergency chest-pain medicines, recreational substances, topical or intermittent products, prescriptions, and supplements. A drug that is used only occasionally can still be relevant to a contraindication.
| Medication class | Clinical concern | Action category |
|---|---|---|
| Organic nitrates / nitric-oxide donors | Potential severe hypotension | Contraindicated |
| Riociguat | Excessive cGMP-pathway blood-pressure effect | Contraindicated |
| Alpha-blockers | Additive symptomatic hypotension | Clinician evaluates stability and regimen |
| Strong/moderate CYP3A4 inhibitors | Raised vardenafil exposure | Product-specific dose/interval restrictions or avoidance |
| Class IA/III antiarrhythmics | QT prolongation concern | Avoid as described in labeling |
| Other PDE5/ED medicines | Combination safety not established | Do not combine without medical review |
Nitroglycerin, isosorbide preparations and recreational nitrites can participate in the nitrate/nitric-oxide pathway that vardenafil amplifies. Severe falls in blood pressure may cause collapse, fainting or ischemic complications. Regular or intermittent nitrate use remains contraindicated.
A patient with chest pain must seek urgent care and disclose recent vardenafil rather than taking a nitrate on a self-calculated timetable. Detailed emergency considerations belong to the dedicated nitrate page.
Riociguat stimulates soluble guanylate cyclase and is used in certain pulmonary-hypertension settings. Its pharmacologic effect can amplify the blood-pressure-lowering consequences of vardenafil, so concomitant use is contraindicated.
It would be unsafe to assume a person is eligible simply because the prescription is for a lung or vascular condition rather than chest pain. The full medication name and indication should be reviewed before any ED drug is chosen.
Strong or moderate CYP3A4 inhibitors include certain protease inhibitors, boosting agents, antifungal medicines and macrolide antibiotics. The U.S. film-coated tablet label gives specific restrictions for combinations such as ritonavir, cobicistat and certain other inhibitors. The degree of interaction is not the same for every pair.
The ODT formulation has separate limitations, including advice not to use it with moderate or strong CYP3A4 inhibitors. Patients should never translate dose-adjustment text intended for film-coated tablets directly to an ODT prescription.
For film-coated vardenafil, one current U.S. label specifies no more than 2.5 mg in 72 hours with ritonavir or cobicistat; it specifies other 24-hour dose limits for particular azole antifungals, protease inhibitors and macrolides. These are drug-specific prescribing limits rather than an invitation to adjust a prescription at home. Crucially, the 10 mg orally disintegrating formulation has different instructions: it should not be used with moderate or strong CYP3A4 inhibitors, rather than simply being reduced to the film-coated tablet limit.
Alpha-blockers prescribed for prostate or blood-pressure conditions can have additive vasodilator effects with vardenafil. Film-coated tablet labeling discusses patient stability and dose modification when the combination is medically appropriate. For the 10 mg ODT, labeling explicitly says not to initiate vardenafil therapy in someone taking an alpha-blocker; patients already established on a film-coated regimen need prescriber review before any ODT change. Additional antihypertensive therapies and volume depletion may further influence risk.
Do not abruptly discontinue an alpha-blocker or blood-pressure medicine so an ED medication can be used. The clinician must decide whether the combination is acceptable and what monitoring or alternative treatment is needed.
Vardenafil labeling advises people with congenital QT prolongation or those taking class IA or class III antiarrhythmic medicines to avoid use. Examples include quinidine or procainamide in class IA and amiodarone or sotalol in class III. This concern differs mechanistically from nitrate-related hypotension.
Other medications that affect cardiac repolarization may also be important to the clinician. A drug-interaction website that screens only for blood pressure may miss this vardenafil-specific issue.
Adding sildenafil, tadalafil, or another PDE5 inhibitor to vardenafil can increase overall exposure to vasodilator effects. The safety and efficacy of such combinations are not established in the product label, so stacking products is not recommended.
A patient who reports inadequate effect should undergo professional review of the original prescription, instructions, response and health status rather than layering medications or using an online “boosting” plan.
Liver impairment, dialysis, cardiovascular disease and advanced age may affect suitability or the approach to treatment. Grapefruit juice may inhibit CYP3A4 and could change vardenafil exposure; the exact clinical significance and patient circumstances need professional interpretation.
The formulation also matters: 10 mg orally disintegrating tablets are not interchangeable with 10 mg film-coated tablets and have different handling and interaction-related instructions. Do not rely on the active ingredient alone when reviewing potential combinations.
In chest-pain or collapse emergencies, report that vardenafil was used, the approximate time, the formulation if known, and other substances taken. This information matters because nitrate treatment is contraindicated and alternative emergency management must be determined by clinicians.
For continued outpatient care, keep a reconciled medication list and ask the pharmacist to check new prescriptions before starting them. The prescription guide explains the clinical screening workflow; the symptom guide distinguishes adverse reactions.
Product labeling notes that grapefruit juice may inhibit CYP3A4, the enzyme important to vardenafil clearance, and could increase exposure. The magnitude and clinical relevance depend on circumstances, but this makes unsupervised assumptions about supplements or food-based interactions unwise.
The prescribing clinician or pharmacist can review frequent grapefruit use and any herbal or over-the-counter products. A general promise that a nonprescription product is “natural” does not establish compatibility.
A patient may receive an antibiotic, antifungal medicine or new cardiovascular drug months after the original ED prescription. A previously acceptable regimen can therefore require renewed review. This is especially relevant when prescriptions are written by clinicians in different specialties.
Keep the medication profile current at the pharmacy and ask before beginning newly prescribed or nonprescription medicines. Waiting until symptoms develop misses the preventive purpose of interaction screening.
No. Concurrent use with organic nitrates is contraindicated because blood pressure can fall dangerously.
No. The combination is contraindicated due to the potential for excessive hypotension.
Moderate or strong CYP3A4 inhibitors—including some antifungals, antivirals and antibiotics—can increase exposure. Film-coated labeling gives medicine-specific limits (for example, with ritonavir or cobicistat), while 10 mg ODT labeling directs avoidance of moderate or strong CYP3A4 inhibitors.
This requires prescriber evaluation of treatment stability and the exact medicines; additive hypotension is possible.
Vardenafil has QT-related warnings, including avoidance in congenital QT prolongation and use with certain class IA/III antiarrhythmics.
No. The 10 mg ODT is not interchangeable with a 10 mg film-coated tablet. It should not be used with moderate or strong CYP3A4 inhibitors and has its own alpha-blocker and liver-function restrictions.
Do not combine ED medicines independently. Combination safety has not been adequately established.
Seek emergency care and tell clinicians about the recent dose; do not self-administer nitrate medicines.