What side effects can this medication cause?

Alprostadil may cause side effects. If you experience any of the following symptoms, call your doctor immediately:

• erection lasting more than 4 hours
• redness, swelling, tenderness, or unusual curving of the erect penis
• nodules or hard areas on the penis
• pain on injection
• bleeding

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online at http://www.fda.gov/MedWatch/report.htm or by phone 1-800-332-1088.