Therapeutic drug monitoring

Question 1

Phenytoin toxicity signs

Answer 1

Ataxia and nystagmus

Question 2

Phenytoin under treatment signs

Answer 2

Seizures

Question 3

Phenytoin toxicity Mx

Answer 3

Seizures

Question 4

Digoxin toxicity signs

Answer 4

Arrhythmias, heart block, confusion, xanthopsia

Question 5

Digoxin under treatment signs

Answer 5

Arrhythmias

Question 6

Digoxin cautions

Answer 6

Hypokalaemia - increases levels
Renal failure
Elderly

Question 7

Digoxin reversal

Answer 7

Digibind

Question 8

Lithium toxicity signs

Answer 8

Tremor, lethargy, fits, arrhythmias, renal failure

Question 9

Lithium cautions

Answer 9

Impaired excretion in hyponatraemia, reduced renal function and diuretics

Question 10

Lithium toxicity Mx

Answer 10

Supportive
Alkaline diuresis
Haemodialysis if >3mmol/L

Question 11

Aminoglycoside toxicity signs

Answer 11

Ears - Tinnitus, deafness
Eyes - nystagmus
Renal failure

Question 12

Aminoglycoside monitoring

Answer 12

Single daily dosing
Monitor peak and trough level before next dose

Question 13

Aminoglycoside Mx

Answer 13

Omit / reduce dose

Question 14

Theophylline and aminophylline toxicity signs

Answer 14

Arrhythmias, convulsions, anxiety, tremor

Question 15

Theophylline and aminophylline under treatment signs

Answer 15

Inadequate relaxation of bronchial smooth muscle

Question 16

Theophylline and aminophylline 1/2 life in smokers, non-smokers and patients with liver disease

Answer 16

Smokers - 4 hrs
Non-smokers - 8 hrs
Liver disease - 30 hrs

Question 17

Theophylline and aminophylline drug interactions

Answer 17

Levels increase with erythromycin, cimetidine and phenytoin

Question 18

Theophylline and aminophylline toxicity Mx

Answer 18

Omit/reduce dose