Phenytoin

Question 1

Introduction

Answer 1

• Anticonvulsant, Anti arrhythmic, Muscle relaxant

Question 2

Pharmacodynamics

Answer 2

• Primary site of action is the motor cortex where seizure activity is inhibited
• Reduces the maximal activity of the brain stem centres, responsible for the tonic phase of a seizure, acts to dampen any unwanted runaway brain activity by reducing electrical conductance

Question 3

Pharmacokinetics

Answer 3

• Rapid absorbtion into circulation
• Widely distributed
• Metabolised hepactically
• Eliminated in the urine