An inherited eye disease that affects the retina. Storage Keep your tablets in the compact pack until it is time to take them. As with sildenafil, a high-fat meal or alcohol keep the body from absorbing it as quickly. Grapefruit and Seville oranges may interact with vardenafil and cause side effects. Always take Levitra exactly as your doctor has instructed you, and check with the doctor if you are unsure. The four main medicines taken by mouth for erectile dysfunction are: Avanafil Stendra.Hearing loss or ringing in ears. Heart attack—pain or tightness in the chest, shoulders, arms, or jaw, nausea, shortness of breath, cold or clammy skin, feeling faint or lightheaded. Low blood pressure—dizziness, feeling faint or lightheaded, . Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash. Viagra, Cialis, Levitra, and Stendra can help a person get and maintain an erection. Learn about the similarities and differences between these medications.