I understand tamsulosin hydrochloride can help males with who have luts due to benign prostrate hypertrophy. can it also help if a person has an overactive detrusor muscle?

No.: Flomax and Avodart help to relax or shrink prostate muscle or tissue to regain an open urethral conduit through an enlarged prostate. Detrol, Ditropan, Toviaz, and Vesicare are antimuscarinics that relax overactive bladder muscle spasms that cause urinary frequency, urgency, and nocturia. Myrbetriq is the newest OAB med that acts on the beta-3 receptor.

Tamsulosin: No does not work that way. Unless overactive badder is related to BPH. Need more details.