Objective: Tadalafil is a selective phosphodiesterase type 5 (PDE-5) inhibitor approved for the treatment of erectile dysfunction. Less is known about the electroencephalography (EEG) effects of PDE-5 inhibitors, and the present study, therefore, examined the risk of EEG abnormalities associated with tadalafil.
Method: EEG recordings from 35 erectile dysfunction patients taking tadalafil (20 mg) were graded for severity of EEG abnormalities (at admission, 2 and 48 hours after tadalafil administration).
Results: At admission, there were no EEG abnormalities. At second EEG, abnormalities occurred in 12 (34.3%) of the 35 patients. Eight (22.9%) patients had mild and four (11.4%) patients had moderate EEG abnormalities. At third EEG, one (2.9%) patient had mild and one (2.9%) patient had moderate EEG abnormalities.
Conclusion: PDE-5 inhibitors may produce EEG abnormalities. Although the exact role of PDE in altering susceptibility to seizure remains unclear, epileptic seizures may occur during treatment with PDE inhibitors.