He instructed the pharmacist to bag the available bottles they have of controlled drugs, or else he would shoot the person closest to him. This medicine usually begins to work for erectile dysfunction within 30 minutes after taking it. It is eliminated predominantly by hepatic metabolism mainly CYP3A4 and is converted to an active metabolite with properties similar to the parent, sildenafil. Proper Use Use sildenafil exactly as directed by your doctor. Fact Checker: Daniel Boyer M. Cialis vs. The titration studies, in which most patients received mg, showed similar results.Maria Hudson. 4 hrs. ago. Anna Nelson. 6 hrs. ago. David Muldon. 8 hrs. ago. Uses. Sildenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, sildenafil works by increasing blood flow to the. A Florida man has been arrested after attempting to hold up a CVS drugstore while demanding “all the Viagra and adderall,” amongst other drugs.. USA Today is reporting that year-old Thomas Mues.