High hs-CRP weakens tadalafil efficacy against erectile dysfunction

Elevated levels of serum high-sensitivity C-reactive protein (hs-CRP) appear to attenuate the response to tadalafil in patients with erectile dysfunction (ED), a recent study has shown.

The study included 282 men (mean age, 36.6±12.0 years) with ED who underwent 6 weeks of tadalafil therapy. Participants were evaluated using the 6-item version of the International Index of Erectile Function (IIEF-6), penile Doppler studies and hs-CRP measurements both before and after the treatment period. The therapeutic response to tadalafil was the primary outcome.

Almost a quarter of the men (23.8 percent; n=67) had vasculogenic ED, as determined by penile Doppler; the remaining had nonvasculogenic condition. The former group had more severe ED (mean IIEF-6 score, 9.2±4.6 vs 14.8±4.7; p<0.001).

Majority (60.9 percent; n=134) showed positive responses to tadalafil therapy, a further 97.0 percent of whom reported symptomatic improvement. Compliance to the intervention was likewise high at 92.3 percent. Headaches (n=3) and backaches (n=11) were the most common reasons for poor compliance.

Responders had significantly lower median baseline concentrations of hs-CRP (1.5 vs 2.0 mg/L; p=0.034), as well as a greater corresponding decline over time (median change, –18.2 percent vs –8.3 percent; p=0.002).

Other variables that may explain response were nonvasculogenic ED, which was significantly more common among responders (96.3 percent vs 50.0 percent; p<0.001), and ED severity (mean IIEF-6: 15.6±4.5 vs 10.7±4.7; p<0.001).