Describe the biochemical abnormalities, and the mechanisms by which they arise, that may be observed in a patient who is taking frusemide.
This was a relatively straightforward question with marks available for listing the
abnormality and then discussing its origin. Many candidates simply listed an abnormality or
confused the direction of electrolyte change. Few candidates went beyond hypokalaemia,
hyponatraemia and hypochloraemia. Several candidates gave confused answers as to the
mechanism(s) or drew pictures of a tubule with directional arrows for electrolytes with
inadequate explanation. Some candidates simply ran out of time and wrote very little – this
is a pity as a list would have generated marks. Candidates are reminded to practise the
exams to time and attempt all questions.
Ok, so it sounds - both from the model answer and from the question wording itself - that this answer was expected as a table of biochemical abnormalities and their physiological causes. One must agree, to draw the tubule and make use of diagrams to explain these concepts is a recipe for disaster, as the author himself had discovered in the process of writing the furosemide chapter. There are probably less verbose methods to present this material, but the objective here was to produce a maximally pre-digested answer with minimal ambiguity. One could potentially save some spacetime by removing some of the more obvious steps and restating some elements in a form where phrases like "ergo, the consequence of" and "and this is the basis upon which" are replaced with "→".
|Diuresis and hypovolemia||
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Ponto, Laura L. Boles, and Ronald D. Schoenwald. "Furosemide (frusemide) a pharmacokinetic/pharmacodynamic review (part II)." Clinical pharmacokinetics 18.6 (1990): 460-71
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