ADME 3

Question 1

What are dose dependent ADRs of phenytoin?

Answer 1

Nystagmus
Vertigo 
Diplopia 
Ataxia 
Drowsiness 
Speech disturbances

Question 2

Does unbound phenytoin increase in renal failure?

Answer 2

Yes

Question 3

How would you describe phenytoin metabolism?

Answer 3

Non linear and zero order pharmacokinetics

Question 4

What is the method commonly used to measure phenytoin concs?

Answer 4

CEDIA cloned enzyme donor immunoassay

Question 5

When should digoxin serum levels be monitored?

Answer 5

IV - 4 hours after

Or 6 hours after oral

Question 6

What are the methods used to monitor serum digoxin concs?

Answer 6

Radioimmunoassay
Fluorescence polarisation immunoassay
Enzyme immunoassay

Question 7

When should digoxin be measured?

Answer 7

Borderline renal function
Aged subjects
Patients with AF who require higher digitalis doses for HR control
Heart failure patients

Question 8

Which drugs don’t need monitoring?

Answer 8

Drugs used in diseases with clear clinical end points
When serum concs don’t correlate with therapeutic of toxic effects
Straightforward pharmacokinetics
Drugs used in non life threatening diseases

Question 9

Do drug metabolites clear more quickly than parent drug?

Answer 9

Yes

Question 10

What scenarios are important when monitoring phenytoin?

Answer 10

Establishing an individual therapeutic conc
Aiding in diagnosis of clinical toxicity
Dosage adjustment to patients with greater pharmacokinetic variability