Limitations & drawbacks…
Penile Injection Therapy has been used for several years to stimulate erections in men with various disorders. It has also been used by men with poor erections due to diabetes and other medical problems for many years. If used properly, it will restore the ability to obtain erections to most men following a spinal cord injury.
However, you should remember that any of the penile injections will not enable you to ejaculate.
What drugs are used in penile injections?
Various drugs have been found to be capable of stimulating erections when injected into the erectile tissue of the penis (the corpora). No single agent is guaranteed to be effective in all cases. However, Papaverine is widely used and accepted. Another drug which is becoming more widely used is Prostaglandin E1 (also known as Caverject).
Mode of action
Almost all of the drugs used in the penile injections have their effect by causing dilatation (widening) of the blood vessels to the penis. Hence, they create an erection by relaxing the smooth muscles and widening the blood vessels in the penis
Limitations of penile injections
Extra care needed: You must inject into a specific area of the penis. This is so you do not injure nerves, arteries, or veins. Do not inject straight down on the top or the bottom of the penis.
Difficult dosage adjustment: It usually takes between two to six injections to find the right dose for an erection firm enough to have sex. It is important that you follow the suggested course of therapy.
Temporary effects: While the erection usually starts between 5 to 10 minutes after the injection, it usually lasts between 1 and 2 hours and not more.
Limited usage: Also, self injection into the penis may be performed a maximum of two to three times per week and never more than once in any 24 hour period.
Like all other drugs, penile injections too have some side effects and these may vary according to the dosage used and the sensitivity of the individual to the substance. Some of the common side effects include:
Prolonged Erection (Priapism): An erection lasting for more than 4 hours has occurred in some cases following penile injection. Sometimes this is due to people injecting themselves with excessive doses of the drug. Occasionally it can happen at the first injection because of the persons sensitivity to the drug.
Abnormal thickening of the penis (Fibrosis): Occasionally after long term use of injection therapy,fibrosis (thickening or hardening) in the erectile tissues of the penis may occur.
Bruising: Bruising at the site of the injection occurs in many cases. This may be tender for a few days and further injection must not be given until there is no sign of any bruising.
Based on the above discussion, it is evident that the option of penile injections to treat erectile dysfunction is not suitable for everyone because of its numerous limitations and high risk of side effects.