Search results
Results From The WOW.Com Content Network
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 .
Acebutolol is a cardioselective beta-1 blocker which also considered a partial agonist due to its intrinsic sympathomimetic activity (ISA). This means it provides low-grade beta stimulation at rest but acting as typical beta-blockers when sympathetic activity is high. [3]
Examples of sympathomimetic effects include increases in heart rate, force of cardiac contraction, and blood pressure. [1] The primary endogenous agonists of the sympathetic nervous system are the catecholamines (i.e., epinephrine [adrenaline], norepinephrine [noradrenaline], and dopamine ), which function as both neurotransmitters and hormones .
The progress in β-blocker development led to the introduction of drugs with variety of properties. β-blockers were developed having a relative selectivity for cardiac β1-receptors (for example metoprolol and atenolol), partial adrenergic agonist activity , concomitant α-adrenergic blocking activity (for example labetalol and carvedilol) and ...
Stutterers also use beta blockers to avoid fight/flight responses, hence reducing the tendency to stutter. Since they promote a lower heart rate and reduce tremor, beta blockers have been used by some Olympic marksmen to enhance performance, though beta blockers are banned by the International Olympic Committee (IOC). [ 3 ]
Levobunolol is a non-cardioselective beta blocker, that is, it blocks beta-1 receptors as well as beta-2 receptors. The latter type dominates in the ciliary body, where it controls aqueous humour production. Blocking this type of receptor reduces aqueous humour production, lowering intraocular pressure.
The combination of beta blockers and antihypertensive drugs will work on different mechanism to lower blood pressure. [17] For example, the co-administration of beta-1 blocker atenolol and ACE inhibitor lisinopril could produce a 50% larger reduction in blood pressure than using either drug alone. [18]
Botulinum toxin A is an example of inhibitors of acetylcholine release, which is a drug for treating overactive bladder. [6] It blocks the release of acetylcholine from the presynaptic neuron and therefore acetylcholine cannot interact with receptors in the postsynaptic neuron to carry on neurotransmission in the parasympathetic nervous system.