Objective: To determine the affinities of human penile alpha-adrenoceptors and cloned human alpha-adrenoceptor subtypes for trazodone, an antidepressant with reported beneficial effects in erectile dysfunction. Materials and methods Competition radioligand binding studies were performed with trazodone in human penile tissue and in cell lines stably expressing all cloned human alpha-adrenoceptor subtypes.
Results: Trazodone had higher affinity for human alpha1-adrenoceptors (10-130 nmol/L) than for alpha2-adrenoceptors (300-700 nmol/L), but did not discriminate between subtypes of human alpha1- or alpha2-adrenoceptors.
Conclusion: Trazodone has high and moderate affinity for human alpha1- and alpha2-adrenoceptors, respectively; this might contribute to its reported beneficial effects in erectile dysfunction.