Tazzle 20 mg contains tadalafil 20 mg. It can interact with blood-pressure medicines because tadalafil itself can lower blood pressure, potentially adding to the effect of other medicines. D DailyMed +1 The interaction is particularly important with: Alpha-blockers such as doxazosin, tamsulosin, or alfuzosin. The combination can sometimes cause significant dizziness or fainting from low blood pressure. D DailyMed +1 Other antihypertensives, including medicines such as amlodipine, ARBs, and other blood-pressure-lowering drugs. Clinical studies generally found relatively modest additional BP reductions with many of these medicines, but individual responses vary. D DailyMed Multiple blood-pressure medicines together, where the combined BP-lowering effect may be more noticeable. Substantial alcohol consumption, which can further increase the risk of low blood pressure and dizziness. D DailyMed Nitrates are different: tadalafil must not be combined with nitrate medicines such as nitroglycerin/GTN or isosorbide because of the risk of a dangerous blood-pressure drop. D DailyMed