Primary Viva 9 (Pharmacology)

Part I

Answer the following questions on local anaesthetics:

1. Compare and contrast lidocaine and bupivacaine. How do they compare with ropivacaine?
2. What is the definition and significance of pKa with regard to the onset of action and duration of action of local anaesthetics?
3. What is the significance of the molecular weight of a local anaesthetic?
4. Discuss the influence of plasma protein binding in relation to the metabolism, duration of effects, side-effects and transplacental transfer of local anaesthetics.
5. What concentrations of local anaesthetics are used in spinal and epidural anaesthesia and in obstetrics?
6. Draw the chemical structure of lidocaine.
7. What are the differences between esters and amides, including the advantages and disadvantages of both?
8. Discuss the toxicity of local anaesthetics to the cardiovascular system, and explain how this should be managed.
9. What are the differences between esters and amides in terms of their central nervous system toxicities?

Part II

1. Discuss the different types of isomerism, giving examples.
2. What are the clinical differences between isomers with regard to pharmacokinetics and side-effects?
3. What are the differences between atropine, and atracurium and cisatracurium?

Part III

1. Define bioavailability and explain how it is calculated for oral administration of a drug.