However, all medications come with risks. It may be difficult to remain firm despite wanting to have sex. You can report an adverse event either online, by regular mail or by fax, using the contact information at the bottom of this page. Levitra vardenafil : This medication is taken one hour before sex and can last up to 24 hours. You can see an in-person provider or speak with a doctor virtually.quality Usually, generic drugs aren’t available until the expiration of the brand name’s patent. Eli Lilly and Company’s patent for Cialis expired in , opening the market to generic. headache *. upset stomach. runny nose. back pain *. upper respiratory infection. heartburn *. muscle pain. For a list of side effects reported by people taking Cialis in clinical trials, including. tadalafil. erectile dysfunction (ED) benign prostatic hyperplasia, or BPH). Tadalafil (Cialis) is available both as brand-name and generic tablets. Common side effects of this .