Outline three (3) factors that alter the pharmacodynamic response of nondepolarising neuro-muscular blocking drugs and describe the mechanism by which they may occur.

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College Answer

There were a number of possible factors that candidates could have selected. Examples
include drug interactions (anticholinesterases, aminoglycoside antibiotics, local
anaesthetics, steroids, antiarrhythmic drugs, anticonvulsants (phenytoin), diuretics,
magnesium, lithium), hypothermia / hyperthermia, acidosis, [k+], burn injury, allergic
reactions, gender, altered elimination due to renal or hepatic dysfunction and disease
states (adrenocortical dysfunction, myasthenia, myopathies, denervation injury). Also extremes of age and pregnancy. Areas of weakness for the candidates were failure to
include sufficient factual knowledge for their selected factors, and as a result, a failure to
illustrate sufficiently the mechanisms by which the pharmacodynamic response of nondepolarising
neuro-muscular blocking drugs may be affected.