CAVERJECT (alprostadil) is used to treat erection problems in adult men. It is given by injection into the side of the penis. CAVERJECT is not for all men. It is not for those who have been advised not to have sex. It is not for men who have penis implants. CAVERJECT should not be used by men with medical problems that can cause long-lasting erections?4 hours or more. Priapism requires immediate medical attention because permanent damage to the tissue of the penis and loss of potency may result. Tell your doctor about all of your medical conditions before using this drug. Call your doctor at once if you still have an erection 4 hours after injection. This is dangerous. You must get medical attention right away. The most common side effect of CAVERJECT is mild to moderate pain after injection. About one third of patients reported this pain but very few stopped CAVERJECT for this reason. Men may get a small amount of bleeding at the injection site. Call your doctor if you notice any redness, lumps, swelling, tenderness or curving of the erect penis. Lumps or curving of the erect penis including a condition called Peyronie's disease was reported in clinical trials with Caverject.