Storage Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Tadalafil Cialis. Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. These medicines all work well for ED. If you see air bubbles in the syringe, repeat the steps.Before taking Viagra, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or . Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss sudden hearing decrease or hearing loss. Some people may also have . If you are a woman of childbearing age taking sildenafil (brand Revatio) for PAH, then tell your doctor if you become pregnant or are intending to become pregnant. It is not known .