indication
For use as adjuncts to anesthesia to induce skeletal muscle relaxation and to facilitate the management of patients undergoing mechanical ventilation
pharmacology
Gallamine Triethiodide is a nondepolarizing neuromuscular blocking drug (NDMRD) used as an adjunct to anesthesia to induce skeletal muscle relaxation. The actions of gallamine triethiodide are similar to those of tubocurarine, but this agent blocks the cardiac vagus and may cause sinus tachycardia and, occasionally, hypertension and increased cardiac output. Muscle groups differ in their sensitivity to these types of relaxants with ocular muscles (controlling eyelids) being most sensitive, followed by the muscles of the neck, jaw, limbs and then abdomen. The diaphragm is the least sensitive muscle to NDMRDs. Although the nondepolarizing neuromuscular blocking drugs do not have the same adverse effects as succinylcholine, their onset of action is slower. They also have a longer duration of action, making them more suitable for maintaining neuromuscular relaxation during major surgical procedures.
mechanism of action
It competes with acetylcholine (ACh) molecules and binds to muscarinic acetylcholine receptors on the post-synaptic membrane of the motor endplate. It acts by combining with the cholinergic receptor sites in muscle and competitively blocking the transmitter action of acetylcholine. It blocks the action of ACh and prevents activation of the muscle contraction process. It can also act on nicotinic presynaptic acetylcholine receptors which inhibits the release of ACh.