Acebutolol HCl is a cardioselective beta-1 blocker with intrinsic sympathomimetic activity (ISA), making it a partial agonist that provides mild beta stimulation at rest while functioning as a traditional beta-blocker during periods of heightened sympathetic activity. This unique action makes Acebutolol a suitable choice for patients who require beta-blocker therapy but are prone to conditions like asthma or COPD, where non-cardioselective beta-blockers may exacerbate symptoms.