Self-injected drugs

For erection problems

Self-injected drugs — or penile injections — are available to help men with erection problems related to prostate cancer treatments.

Self-injected drugs are injected through a small needle into the base of the penis, causing it to become engorged with blood.

These drugs include:

  • Papaverine hydrochloride
  • Phentolamine
  • Alprostadil (brand names are Caverject and Edex)

Only alprostadil is currently approved for erectile dysfunction in the U.S.  It is a commercially created version of prostaglandin E1, a natural substance a man’s body makes to produce erections.

Alprostadil is highly effective and causes an erection firm enough for sexual intercourse in about  80% of men, according to the Cleveland Clinic.  

How self-injected drugs work

The drug is typically injected 5 to 20 minutes prior to having sex and may last from 30 minutes to an hour or more.

There are different dosages available and it may take some trial and error to find the right dose.

Your loved one’s doctor will most likely do the first injection in the office to show you how it’s done.

A delicate matter

While these drugs can often be very effective, some men may be adverse to the idea of sticking a needle in their penis.

If impotence continues to be a problem, however, your loved one may eventually warm up to the idea of using a needle.

If your man has eyesight or dexterity problems, then you will have to be the one to do the injection.

But the good news is when the injection is done correctly, it shouldn’t be painful.

Plan ahead

Men may experience some slight soreness after the injection.  So you may want to plan to use the drug when you don’t have to go anywhere or do anything physical afterwards.

There are also usually limitations to how often these drugs can be used. The doctor should give you specific instructions.

It’s also important to discuss any other health problems your loved one has — or other medications he is taking — with his doctor.

Side effects

While most side effects are generally expected to be minimal, sometimes these drugs can cause unwanted side effects with repeated use, such as scarring or curving of the penis.

If your loved one has an erection for more than 4 hours (called priapism), seek immediate medical attention.

Return to sex after prostate cancer
Erectile dysfunction drugs
Vacuum pump devices
Urethral pellets
Penile implants


Alprostadil (Injection therapy).
/hic_Alprostadil_Injection_therapy.  Accessed March 31, 2015.

The American Cancer Society. Prostate Cancer. Accessed March 17, 2015.

National Kidney and Urologic Diseases Information Clearinghouse. Erectile Dysfunction. Accessed November 30, 2008.

Walsh PC. Guide to Surviving Prostate Cancer. New York, NY: Time Warner Book Group; 2001.

Always consult a medical professional.

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