What additional property does acebutolol possess compared to traditional beta-blockers?

Acebutolol is unique among beta-blockers because it has intrinsic sympathomimetic activity (ISA). This means that, unlike traditional beta-blockers that primarily block the action of adrenaline and norepinephrine at beta-adrenergic receptors, acebutolol can activate beta receptors to a certain degree while still blocking them. This dual action allows it to exert a more moderate effect on heart rate and cardiac output, especially at rest, compared to non-ISA beta-blockers which can lead to significant decreases in heart rate.

This intrinsic sympathomimetic activity makes acebutolol particularly beneficial for patients who may experience bradycardia or other adverse effects from pure beta-blocker therapy. Furthermore, the presence of ISA helps to maintain normal cardiac function and can sometimes reduce the risk of side effects typically associated with conventional beta-blockers.

The other options do not accurately describe properties associated with acebutolol. For instance, uricosuric activity is not characteristic of beta-blockers, and neither nephrotoxic effects nor proarrhythmic effects are considered additional properties of acebutolol. Thus, its intrinsic sympathomimetic activity distinguishes it from traditional beta-blockers, highlighting its unique biochemical behavior and therapeutic implications