© The Canadian Journal of Urology™; 19(Supplement 1); October 2012
21
Erectile dysfunction and testosterone deficiency syndrome: the “portal to men’s health”
Topical prostaglandin
The topical prostaglandin cream, Vitaros (alprostadil)
was approved by Health Canada and is under review
by the FDA for the treatment of ED. Vitaros is applied
directly to the penis and is quickly absorbed through
the skin, resulting in a faster onset of action than the
oral ED therapies. The topical application of Vitaros
may be associated with a lower risk of side effects,
making it a treatment alternative for men who are
unable to use or tolerate PDE-5 inhibitors. Penile
burning sensation has been reported as a side effect in
some of the clinical trials. It is not officially launched
in Canada yet.
Other treatment options
Patients who do not respond to oral therapy or cannot
use PDE-5 inhibitors (e.g., due to concomitant use of
nitroglycerin) still have other viable options. Theymay
respond to transurethral or intracavernosal therapies
for ED, see Table 2.
concern, since patients may unknowingly be taking a
PDE-5 inhibitor, placing those with contraindications
at risk of a serious adverse event.
In 2010, it was estimated that the global illicit drug
market was a $75 billion industry.
19
PDE-5 inhibitors
are prime targets for counterfeiters.
20
It is estimated that
between 4500 and 15000 websites offer online ordering
of PDE-5 inhibitors and other substances purported
to treat ED. These sites receive 13 million visitors a
month and sell about 2.3million tablets amonth. More
than 80% of these purchases were conducted without
the patient providing a prescription or any medical
history. About 10%of thesemedications contain toxins
such as boric acid, highway paint (that contains lead),
floor polish, heavy metals, nickel, arsenic, and brick
dust.
21
Patients need to be discouraged from seeking
treatments from these websites. This is a good reason
to initiate a discussion about sexual dysfunction with
patients, so that diagnosis and treatment of ED occurs
under proper medical supervision.
TABLE 2.
Transurethral (TU) and intracavernosal (IC) therapy for erectile dysfunction (ED)
Name (Brand name) Dosage
Mechanism of action
Side effects/Notes
Alprostadil TU
250
mcg-1000 mcg
Synthetic PGE1 stimulates
Painful erection; urethral pain;
(
MUSE)
Max 2 administrations
increased levels of cAMP
bleeding; priapism (rare)
per 24 hrs
Alprostadil cream
Synthetic PGE1 stimulates
Penile burning sensation
(
Vitaros [approved
increased levels of cAMP
in Canada])
Alprostadil IC
2.5
mcg-20 mcg*
Same as above
Penile pain, fibrosis
(
Caverject, Edex
†
)
Max 1x daily and
hematoma; priapism (rare)
3
x weekly
Papaverine IC
‡
15
mg-60 mg
Non-selective PDEi
Priapism; fibrosis
(
monotherapy)
increases cAMP and cGMP
5
mg-20 mg
(
combination therapy)
Phentolamine IC
‡
0.5
mg-1 mg
Alpha blocker inhibiting
Hypotension; reflex
(
combination therapy
sympathetic tone to penis
tachycardia
with papaverine)
Bimix (papaverine Papaverine 30 mg/mL
Less penile pain compared to
and phentolamine) + phentolamine 1 mg/mL
monotherapy with alprostadil.
in a 1:1 ratio
More potent than monotherapy
with alprostadil
Trimix (papaverine, Papaverine 30 mg/mL
Less penile pain than alprostadil
phentolamine, and + phentolamine 1 mg/mL
monotherapy. More potent than
alprostadil)
+ alprostadil 20 mcg/mL
bimix
in a 1:1:1 ratio
*
Neurogenic ED may require lower starting dose. Severe vascular ED may require higher doses
†
Not available in Canada;
‡
Not approved by Health Canada for this use
