Erectile Dysfunction Medications Related to Transient Amnesia, FDA Warns

According to WebMD:

All three erectile dysfunction drugs -- Cialis, Levitra, and Viagra -- now list rare reports of transient global amnesia on their labels.

What is transient global amnesia (TGA)?

TGA is a brief episode amnesia lasting less than 24 hours, without causing other problems. TGA has been a well-described phenomenon for more than 40 years.

Diagnostic requirements for TGA include:

- The attack was witnessed and reported as being a definite loss of recent memory (anterograde amnesia).
- There was an absence of clouding of consciousness.
- There were no focal neurological signs or deficits during or after the attack.
- There were no features of epilepsy, and the patient did not have any recent head injury or active epilepsy
- The attack resolved within 24 hours

The underlying cause of TGA is unclear. It may be due to venous congestion of the brain, leading to ischemia of the hippocampus (involved with memory, shown in the image above). The ischemia may be triggered by immersion in cold water, sexual activity, severe emotional stress and vigorous exertion.

The prognosis of TGA is very good but the annual recurrence rate is 4-5%.

There is no proof that the erectile dysfunction drugs actually cause transient global amnesia, which can happen for various reasons, and can be triggered by the sexual encounter itself.

However, FDA required that all erectile dysfunction drugs must list the TGA warning on their labels in the "Post-Marketing" section.

Note: All those ready to make "such a convenient excuse" jokes must be aware that TGA can be a very disturbing experience for the patient.

References:

Cialis, Viagra Labels to Note Amnesia. WebMD.
Hodges JR, Warlow CP Syndromes of transient amnesia: towards a classification; a study of 153 cases. Neurosurg Psychiatry 1990;53:834–43.
Transient global amnesia, from Wikipedia, the free encyclopedia.
Transient Global Amnesia. eMedicine.
Sex, then amnesia...and it's no soap opera. CNN, 2009.
Image source: Hippocampus, from Wikipedia, public domain.

Related reading:

“Forgettable” Sex: A Case of Transient Global Amnesia Presenting to the Emergency Department http://goo.gl/6Rfrt
How sex and stress made one man lose his memory. The Daily Mail, 04/2010.

Men who use ED drugs have higher rates of STDs, particularly HIV infection - Ann Intern Med http://goo.gl/UH78

ED, Depression, Heart Disease: Does the Existence of One Component of This Triad Necessitate Inquiring the Other Two? http://goo.gl/EKvKl