Take this medication as directed by your doctor, usually as needed. Take vardenafil, with or without food, about 1 hour before sexual activity. Do not take more than once daily. Doses should be taken at least 24 hours apart. Dry your hands before handling this medication. Remove the dose from the blister package right before use. Place the tablet on your tongue and allow it to dissolve completely. Do not crush or split the tablet. This medication should not be taken with liquid. Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details. Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval. A product that may interact with this drug is: riociguat. concerta can cause a serious drop in your blood pressure when used with nitrates, which can lead to dizziness, fainting, and rarely heart attack or stroke. Do not use 54mg concerta with any of the following: certain drugs used to treat chest pain/angina (nitrates such as nitroglycerin, isosorbide), recreational drugs called “poppers” containing amyl or butyl nitrite.