Question 14

Describe the pharmacology of sodium bicarbonate.

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College Answer

This question was best answered with a structured approach as per any pharmacology question. It nonetheless required good understanding of various aspects of physiology. Many candidates failed to gain marks by omitting to mention facts which could have been prompted by a defined structure. A good response mentioned the pharmaceutic features including formulation and the hypertonicity of IV bicarbonate, pharmacodynamics including indications for use, mode of action, adverse effects (systemic and local), pharmacokinetics and dose. Pleasingly a few candidates stated that sodium bicarbonate’s mechanism of action to cause alkalosis involved increasing the strong ion difference in plasma. Credit was also given for stating the mechanism of action as providing bicarbonate ions to augment the extracellular buffer system.