Vilitra 40 mg (vardenafil) can lower blood pressure because vardenafil relaxes blood vessels. However, 40 mg is above the usual maximum recommended dose of 20 mg for erectile dysfunction. The blood-pressure effect can be more significant if you also take: Nitrate medicines such as Vilitra 40 mg — this combination is contraindicated because it can cause a dangerous blood-pressure drop. Alpha-blockers or other blood-pressure medicines. Other medicines that increase vardenafil levels. For comparison, studies with the recommended 20 mg dose found an average maximum blood-pressure reduction of about 7 mmHg systolic and 8 mmHg diastolic, occurring roughly 1–4 hours after dosing. If you've already taken Vilitra 40 mg and you're experiencing severe dizziness, fainting, chest pain, or a very low blood pressure reading, seek urgent medical care.