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Injected Medicines for Erection Problems

Examples

Generic Name Brand Name
alprostadil Caverject, Edex
alprostadil and phentolamine Bimix
papaverine and phentolamine Bimix
papaverine and phentolamine and alprostadil Trimix

The medicines in Bimix and Trimix must be mixed together by the pharmacist.

You inject this medicine into the side of the penis with a tiny needle.

See a picture of an injection camera.gif.

Your doctor may give you a trial use of this medicine while you are in the office. This allows the doctor to see how well the medicine works for you, see whether you can use it properly, and check for adverse reactions, such as a painfully long-lasting erection (priapism) or an allergic reaction.

How It Works

The medicines are injected into the penis before sex to relax the muscles that surround the blood vessels in the penis, increasing the blood flow into the penis and producing an erection that lasts 30 minutes to an hour or longer. How long the erection lasts depends on how much medicine you inject.

Why It Is Used

These medicines may be prescribed for erection problems (erectile dysfunction) caused by psychological or physical factors.

How Well It Works

  • Alprostadil alone works in about 7 out of 10 men who try it for erection problems.1
  • The combination of papaverine and phentolamine or alprostadil and phentolamine (Bimix) works for about 9 out of 10 men who use it.1
  • Trimix (the combination of papaverine, phentolamine, and alprostadil) works for about 9 out of 10 men who try it.1

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call911or other emergency services right away if you have:

Alprostadil

Call your doctor right away if you have:

  • Hives.
  • An erection that lasts longer than 3 hours or is painful.
  • Bleeding from the shot that does not stop after 10 minutes.
  • Signs of getting too much medicine, such as:

Common side effects of this medicine include:

  • Bleeding where you gave the shot. If you have bleeding, put pressure on it until it stops.
  • Pain from the shot.

Papaverine

Call your doctor right away if you have:

  • Hives.
  • An erection that lasts longer than 3 hours or is painful.
  • Bleeding from the shot that does not stop after 10 minutes.
  • Signs of liver damage, such as yellow skin or eyes.

Common side effects of this medicine include:

  • Bleeding where you gave the shot. If you have bleeding, put pressure on it until it stops.
  • Constipation or diarrhea.
  • Dizziness.
  • Flushing or sweating.
  • Nausea, stomach upset, or not wanting to eat.
  • Pain from the shot.

Phentolamine

Call your doctor right away if you have:

  • Hives.
  • An erection that lasts longer than 3 hours or is painful.
  • Bleeding from the shot that does not stop after 10 minutes.

Common side effects of this medicine include:

  • Bleeding where you gave the shot. If you have bleeding, put pressure on it until it stops.
  • Fast or slow heartbeats.
  • Low blood pressure, which can make you dizzy.
  • Nausea or stomach upset.
  • Pain from the shot.
  • Stuffy nose.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

When thinking about injections for erection problems, it is important to include your partner in your decision.

Medicines that are injected into the penis can be given no more than every other day. Excessive use may cause scarring.

Up to 6 out of 10 men stop using the medicines. Reasons include:2

  • Not wanting to use injections because of fear, discomfort, and the loss of spontaneity about giving an injection into the penis, or some other reason.
  • Partner relationship issues (being able to have erections doesn't solve relationship problems), or loss of partner.
  • Cost of the medicines.
  • Not being happy with the quality of erections from injections.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Checkups

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

  1. Burnett AL (2012). Evaluation and management of erectile dysfunction. In AJ Wein et al., eds., Campbell-Walsh Urology, 10th ed., vol. 1, pp. 721–748. Philadelphia: Saunders.

  2. Bella AJ, Lue TF (2008). Male sexual dysfunction. In EA Tanagho, JW McAninch, eds., Smith's General Urology, 17th ed., pp. 589–610. New York: McGraw-Hill.

By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Christopher G. Wood, MD, FACS - Urology, Oncology
Current as of May 14, 2012

WebMD Medical Reference from Healthwise

Last Updated: May 14, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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