Phenytoin

Question 1

absorption

Answer 1

entirely absorbed following administration

Question 2

distribution

Answer 2

extensively plasma protein bound

Question 3

metabolism

Answer 3

transformed into a reactive arene oxide intermediate and metabolised by CYP450 enzymes

Question 4

excretion

Answer 4

renally

Question 5

MOA

Answer 5

1. an anticonvulsant drug
2. works by inhibiting the positive feedback loop
3. leads to neuronal propagation of high frequency action potentials
4. acts primarily at the glutaminergic synapse and inhibits voltage gated sodium channels

Question 6

indications

Answer 6

1. tonic clonic seizures, focal seizures

Question 7

adverse effects

Answer 7

• electrolyte imbalance
• bone disorders
• rash

Question 8

interactions

Answer 8

• amiodarone
• verapamil

Question 9

contraindications

Answer 9

• second and third degree heart block
• sinus bradycardia
• stokes adams syndrome