Pancuronium Metocurine

It has long been accepted that respiratory acidosis tends to potentiate the blockade produced by non-depolarizing relaxants and respiratory alkalosis produces resistance to their action. This is true for the monoquaternary agents D-tubocurarine, vecuronium, and rocuronium (possibly by increased conversion to the bisquaternary forms at lower pH), but it may not hold for the bisquaternary relaxants metocurine, pancuronium, and alcuronium (97-99). 

NMBAs are further differentiated by their duration of action during anesthesia. Succinylcholine and mivacurium are common ultra-short-acting competitive NMBAs (5-10 min). An intermediate duration of action (30-45 min) is maintained with the use of atracurium, cisatracurium, rocuronium and vecuronium. A long-lasting duration of action (90-100 min) is observed with d-tubocurarine, doxacurium, metocurine, pancuronium and pipecuronium. 

Anticipate the need to use more (possibly up to twice as much) doxacu-rium, metocurine, pancuronium, pipecuronium, rocuronium and vecuronium in patients who have taken these antiepileptics for more than a week, and expect an accelerated recovery. The effects on tubocurarine and atracurium appear only to be small or moderate, whereas mivacurium appears not to interact. 

Tubocurarine, metocurine, and succinylcholine have all been shown to elicit histamine release in humans. However, histamine release is less common with pancuronium and alcuronium. Vecuronium does not cause histamine release. 

Lebowitz PW, Ramsey FM, Savarese JJ, Ali HH. Potentiation of neuromuscular blockade in man produced by combinations of pancuronium and metocurine or pancuronium and d-tubocurarine. Anesth Analg 1980 59(8) 604-9. 

Booij LH, Krieg N, Crul JF. Intradermal histamine releasing effect caused by Org-NC 45. A comparison with pancuronium, metocurine and d-tubocurarine Acta Anaesthesiol Scand 1980 24(5) 393-4. 

Atracurium, doxacurium, pancuronium, pipecuronium, d-tubocurarine, mivacurium. and metocurine are examples of nondepolarizing blockers. 

Examples iTubocurarine chloride Metocurine iodide Gallamine triethiodide Pancuronium bromide Hexafluoronium bromide Fazadinium bromide Alcuronium chloride Dacuronium bromide and Stercuronium iodide. 

These reports contrast with another, in which 25 patients who had no adrenocortical dysfunction or histories of corticosteroid therapy were given pancuronium, metocurine, tubocurarine or vecuronium. They showed no changes in their neuromuscular blockade when given a single intravenous dose of dexamethasone 400 micrograms/kg or hydrocortisone 10 mg/kg. 

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