Dr. Williams discusses the possible side effects of Viagra. Mild side effects include headache, upset stomach, stuffy nose and flushing of the face. Rare side effects of Viagra include change in vision (bluish or greenish tint) and sudden vision or hearing loss. Remember, DO NOT take Viagra if you are taking nitrates of any kind, or if you have a heart condition. In order to avoid drug interactions, be sure to inform your doctor(s) about all medications you are currently taking. Dr. Williams also provides a useful tip on âhow to share your medications with your doctor.â Remember to visit http://www.accessrx.com to learn more about Viagra, Cialis and Levitra.