Tazzle 20 Mg contains tadalafil, people who already have low blood pressure (hypotension) should generally not use it without medical assessment, because tadalafil can further lower blood pressure. Particular caution is needed for people who: Have persistently or significantly low blood pressure. Take nitrate medicines such as nitroglycerin or isosorbide — tadalafil must not be combined with these because of the risk of a dangerous blood-pressure drop. Take alpha-blockers or blood-pressure medicines, which can add to tadalafil's blood-pressure-lowering effects. Drink substantial amounts of alcohol, which can increase the risk of dizziness and hypotension. If someone taking tadalafil becomes very dizzy, faints, or develops chest pain, they should seek urgent medical attention. If you already have low blood pressure, a doctor or pharmacist should review your blood-pressure readings and current medicines before Tazzle 20 Mg is used.