What Are Isa Beta Blockers

Intrinsic sympathomimetic activity (ISA) characterizes a group of beta blockers that are able to stimulate beta-adrenergic receptors (agonist effect) and to oppose the stimulating effects of catecholamines (antagonist effect) in a competitive way.

When should I use an ISA beta blocker?

Beta blockers with ISA may be used in clinical situations where non-ISA beta blockers are relatively contraindicated, such as sinus bradycardia, sick sinus syndrome, Raynaud-like symptoms and chronic obstructive lung disease.

What beta blocker has intrinsic sympathomimetic activity?

Some beta blockers (e.g. oxprenolol, pindolol, penbutolol, labetalol and acebutolol) exhibit intrinsic sympathomimetic activity (ISA). These agents are capable of exerting low-level agonist activity at the β-adrenergic receptor while simultaneously acting as a receptor site antagonist.