You’ve seen the ads, ad nausem. Cialis, Viagra and Levitra 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