UCSB- Pharmacology MT 2

Succinylcholine Chloride
Depolarizing Agent that blocks the neuromuscular response. Functions as a rapid onset, short duration muscle relaxant during surgery. Binds to acetylcholine receptors to produce a prolonged action potential by keeping sodium channels open. Degraded by plasma cholinesterase in the plasma membrane. Block is unaffec ted or increased by anticholinesterase drugs. **SIDE EFFECTS: bradycardia, muscle spasms, cardiac arrythmeias, elevated intraocular pressure, malignant hypothermia, electrolyte imbalance

Malignant Hyperthermia
Mutation in sarcoplasmic reticulum, causing too much calcium release. Leads to elevated body temperature, muscle spasms, “tuna burn”. Must be pre-treated with SR calcium blocker that target the ryanodine receptors.

Atracurim
Competitive (non-depolarizing) antagonist for acetylcholine. Binds to acetylcholine receptor at motor end plate and blocks binding action of acetylcholine. Slow onset with a longer duration. Treatment for surgical muscle relaxant and intubation. Hydrolyzed in plasma by plasma esterase and Hoffman elimination. Reversed by anticholinesterase drugs because less acetylcholine will be broken down, therefore acetylcholine will outcompete the non-depolarizing antagonist. **SIDE EFFECTS: hypotension by induction of histamine release, no activation of parasympathetic nicotinic receptors