Post-marketing reports
Recently, the US Food and Drug Administration (FDA) warned of a reasonably plausible temporal relationship of sudden sensorineural hearing loss (SSHL) with the use of sildenafil, tadalafil and vardenafil. This warning was based on 29 post-marketing cases that occurred with patients on sildenafil, tadalafil and vardenafil. Of these 29 reports, sildenafil accounted for 19 of these cases, while vardenafil and tadalafil each accounted for five of them. In approximately one-third of the cases, the hearing loss was temporary, with majority of the cases reporting onset of SSHL within 24 hours of PDE5 inhibitors use. In some reports, the sudden loss or decrease in hearing was accompanied by vestibular symptoms such as tinnitus, vertigo, and dizziness.
Mechanism of SSHL
According to the National Institute on Deafness and Other Communication Disorders (NIDCD), SSHL, more commonly known as “sudden deafness”, is a rapid loss of hearing that can occur all at once or over a period of up to three days. The mechanism behind how PDE5 inhibitors may be associated with SSHL remains unclear. There is not enough information to determine whether any specific type of patient is at increased risk for this possible adverse effect. In addition, it is uncertain whether these events are caused by medication use, underlying medical conditions, or a combination of both or other factors
Regulatory actions by FDA
Following FDA's warning, the product label for this class of drugs was revised to reflect this information and guidance was also provided in the label for patients who experience sudden hearing loss.
Local situation
Physicians should also advise their patients with PAH, who experience a sudden decrease or loss of hearing while taking Revatio® to seek prompt medical attention. In addition, these patients should be told not to discontinue the medication without consulting their physician about other treatment options, as PAH can be a life-threatening condition.
Both the local package inserts of Viagra® and Revatio® have recently been updated to reflect the warning on hearing loss. The package insert of Levitra® is in the process of being updated with this safety warning. Healthcare professionals are encouraged to report suspected PDE5 inhibitors related adverse events to the Pharmacovigilance Unit of HSA.
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