B1.ii · Drug Absorption

This VIVA will examine general pharmacology. Define bioavailability and explain how can you use this curve to calculate it? (Image removed from report.)

This Viva will explore your knowledge of basic pharmacology and poisoning. Q 1. Describe the factors that affect ORAL drug absorption This viva explored basic pharmacology, dose response curves and poisoning as it related to paracetamol, aspirin and organophosphates. Areas of weakness included the depth of knowledge regarding basic pharmacology as it related to concepts such as clearance and bioavailability and first pass metabolism.

This station will explore knowledge of beta adrenoreceptor antagonists A 50 year-old man is admitted to intensive care after a suspected myocardial infarction while undergoing gastrectomy for carcinoma of the stomach. Cardiologists have recommended metoprolol 50 mg orally bd. Describe the pharmacokinetics of metoprolol. What parenteral dose would you use for this patient? Candidates were provided with a clinical scenario of a patient unable to take oral formulation of metoprolol and asked to describe the pharmacology associated with an alternative, intravenous preparation, and contrast it with the oral preparation. Candidates were also asked to discuss metoprolol associated adverse effects and their knowledge of agonist – antagonists relationships. Candidates struggled most with applying, and explaining the relevance of, basic pharmacological principles to account for fundamental clinical applications. Dose response curves were also not covered well.

of this drug. Candidates were expected to discuss administration, bioavailability, metabolism, excretion and half life of captopril. Candidates were then asked to compare it to the longer acting ACE inhibitors and discuss their advantages and/or disadvantages in ICU patients. The Viva then explored the candidate’s knowledge of dosing intervals, plasma concentration times curves and effect time curves in relation to ACE inhibitors. Candidates were expected to know why these curves differed, (avid enzyme binding), and thus why the dosing intervals for ACE inhibitors are so long in relation to their half lives. The concepts of Emax, EC50 and Therapeutic index were required. Candidates were then asked to discuss the mechanism of action of ACE inhibitors and their cardiovascular, endocrine, renal and CNS effects. Drug interactions and adverse effects were expected knowledge. Syllabus, General Pharmacology I and II, ACE inhibitors, C2b2f. References : Katzung B.G.'s'Basic and Clinical Pharmacology' Brunton L.L. Goodman and Gilman’s ' The pharmacological basis of Therapeutics'.