While not a large amount, more than I would like to see in a product like this. What special precautions are there? Vardenafil may increase the antihypertensive activities of Cyclothiazide. This effect manifests first as a fall in hemoglobin levels, which occurs quite predictably once a cumulative dose of 20 g has been given. If you have a stomach ulcer or other stomach disorders, kidney, liver or heart problems. Desvenlafaxine may increase the serotonergic activities of Fluoxetine.