Ritonavir Norvir or indinavir sulfate Crixivan saquinavir Fortavase or Invirase or atazanavir Reyataz. If you experience a sudden decrease or loss of vision, stop taking PDE5 inhibitors, including Levitra, and call a doctor right away. Remove an orally disintegrating Staxyn tablet from the package only when you are ready to use the medicine. What are the possible side effects of Levitra? Place the tablet in your mouth and allow it to dissolve without chewing.About Vardenafil (Levitra) for ED. Levitra (vardenafil hydrochloride) is an oral medication taken to treat erectile dysfunction (ED). It’s in the same class of drugs as other popular ED.  · Levitra works by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Levitra is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Levitra does not cure erectile dysfunction or increase sexual desire. Vardenafil (Levitra): Uses, Alternatives, Side Effects & More – GoodRx. feeling faint or weak, dizziness, blurry vision, feeling confused. Erection lasting for more than 4 hours. Headache (up to 15%) Flushing (up to 11%) Stuffy nose (up to 9%) Indigestion (up to 4%) —skin rash,, swelling of the face, lips, tongue, or throat.