|papaverine and phentolamine
|papaverine hydrochloride and phentolamine mesylate and alprostadil
The medicines in Bimix and Trimix must be mixed together by
You inject this medicine into the side of the
penis with a tiny needle.
picture of an
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
Why It Is Used
These medicines may be prescribed
erection problems (erectile dysfunction) caused by
psychological or physical factors.
How Well It Works
Papaverine by itself works in about
half of the men who try it for erection problems. Alprostadil alone works in
about 8 out of 10 men who try it for erection problems. The combination of
papaverine and phentolamine (Bimix) works for about 7 out of 10 men who use it.
Trimix (the combination of papaverine, phentolamine, and alprostadil) seems to
work the best. It works in almost 9 out of 10 men who try it.2
Injections sometimes can result in a
painful, prolonged erection (priapism). Call your doctor if an erection lasts
longer than 3 hours. If the erection isn't relieved, it may damage tissues
inside the penis.
Other side effects of injections may
- Pain in the penis. Injecting the medicine slowly may
help prevent pain.
- Formation of scar tissue in the penis (fibrosis).
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
These medicines are less likely to be effective for men
in whom blood flow into or out of the penis is severely impaired.
They may cause problems for men with severe mental illness or for those
who would have difficulty giving the injection. If you have vision problems,
your partner can learn to give you the injections. Make sure your partner is
comfortable with helping you and with using injections.
Medicines that are injected into the penis
can be given no more than every other day. Excessive use may cause
Some men may find the idea of self-injections
unpleasant, or they may find self-injections difficult to do. The use of an
auto-injector, in which the needle is hidden, may make the shots easier for
some men to use.
Couples trying to have children may prefer
injections over a vacuum device, because the vacuum device blocks
Up to 60% of men stop using the medicines. Reasons
- 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
- Cost of the medicines.
- Not being happy with
the quality of erections from injections.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
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.
Lue TF, Broderick GA (2007). Evaluation and
nonsurgical management of erectile dysfunction and premature ejaculation. In AJ
Wein, ed., Campbell-Walsh Urology, 9th ed., vol. 1, pp.
750-787. Philadelphia: Saunders Elsevier.