Vilitra 40 mg (vardenafil 40 mg), I would not consider it a safe routine dose. Standard vardenafil tablets are available at 2.5, 5, 10, and 20 mg, with 20 mg generally the maximum recommended dose. D DailyMed Vardenafil has important interactions with: Nitrates such as nitroglycerin or isosorbide — do not combine; blood pressure can fall dangerously. D DailyMed Riociguat — contraindicated because of potentially severe low blood pressure. D DailyMed Alpha-blockers such as tamsulosin, alfuzosin, and doxazosin — can Vilitra 40 mg additional blood-pressure lowering. D DailyMed Strong CYP3A4 inhibitors, including ketoconazole, itraconazole, ritonavir, clarithromycin, and some HIV medicines — these can greatly increase vardenafil levels, requiring much lower doses. D DailyMed Other ED medicines such as sildenafil (Cenforce/Fildena/Malegra) or tadalafil (Cialis/Vidalista) — don't combine them unless specifically directed by a doctor. If you're considering Vilitra 40 because 10 or 20 mg isn't working, don't simply increase the dose. Tell me what other medicines you take and the vardenafil dose you've tried, and I can help you assess the safer options.