How does solifenacin + tamsulosin work to relieve urinary symptoms associated with benign prostatic hyperplasia?

In Vesomni (solifenacin + tamsulosin), solifenacin blocks muscarinic receptors to improve bladder storage symptoms, while tamsulosin blocks alpha1-adrenoceptors, relaxing smooth muscle in the prostate, bladder neck and urethra to relieve obstruction and improve urine flow and storage symptoms.