You’ve seen the ads, ad nausem. Cialis (tadalafil), Viagra
(sildenafil) and Levitra (vardenafil) are prescription drugs
used to treat erectile dysfunction. Known as PDE5 inhibitors,
they work by increasing blood flow to certain areas of the
penis. Like all medications, they have side effects that divers
need to consider. Most worrisome is a potentially dangerous
decrease in blood pressure in those taking certain other
drugs that also dilate blood vessels. Nitroglycerin, a drug
sometimes prescribed for chest pain due to coronary heart
disease, is the principal example.
Aside from this, possible side effects tend to be transient
and only mild to moderate, but still can be problematic for
divers. In order of reported frequency, these include headache,
upset stomach and nasal congestion. Cialis also may
cause muscle aches and sore back.
Taking one of these medications in proximity to diving
could impede equalization of the ears and sinuses; cause a
headache and sore muscles; and result in heartburn, bloating,
nausea and burping. These complaints could be further
exacerbated by the prone and sometimes head-down positions
assumed while diving. The well-known “blue vision”
(seeing a blue tinge to objects) that is a potential side effect
of Viagra also can occur with Cialis and Levitra. Those with
retinal disease will want to consult with their ophthalmologist
before starting the drug.
A diver taking one of these drugs will want to monitor
for topside adverse reactions before diving. Among other
advantages, this may prevent symptoms like headache and
muscle ache from being confused with decompression illness
or vice-versa.
There is no reason to suspect these medications increase
the likelihood of DCI. In fact, there is theoretical reason as
well as preliminary research suggesting that PDE5 inhibitors
and other drugs that enhance nitric oxide activity actually
could reduce such risk, but this work has a long way
to go. Of course, any limitations or risks imposed by the
condition(s) causing the erectile dysfunction, e.g., diabetes,
obesity, psychiatric disorder, also must be considered.
As a final note, be aware that Cialis has a much longer
half-life than either Viagra or Levitra, and with regular
and continued use, Cialis blood levels go on rising for
about a week.
- - Doc Vikingo