This medicine is expected to be taken approximately 40 mins before making love and could offer around 36 hrs of performance. Both light and major side effects are possible when taking tadalafil 20 mg medication. This medicine is never supposed to be integrated with nitrates - medicines such as butyl nitrate, amyl nitrate, isosorbide dinitrate, nitroglycerin, or isosorbide mononitrate, as this might lead to really significant effects - movement, fainting and even fatality. Every dosage is recommended based upon the mindful analysis of the patient's health.