Precautions for concomitant use of ED treatments and list of contraindicated drugs Concomitant precautions common to Viagra, Levitra and Cialis Concomitant precautions You can use concomitant medications for ED if you are careful about their precautions. Alpha blockers: Some of the treatments for hypertension and prostatic hypertrophy (hereinafter, the main alpha blockers from Harnal to […]