[Priapism following off-label use of tamulosin].

Selective postsynaptic alpha1-adrenergic blocking agents such as tamsulosin are mainly used for treating micturition symptoms due to prostatic hyperplasia. They are also used off-label in patients with a distal ureteral stone to enhance passage of the stone. This application is based on the smooth muscle relaxant effect of alpha1-receptor blockade. Smooth muscle relaxation in the penis leads to penile tumescence. The case was reported of a 47-year-old man with a distal ureteral stone who presented with priapism after using tamsulosin 0.4 mg once daily for 9 days. Male patients receiving off-label alpha1-blocking agents should be informed about this adverse effect.