Learning Topic questions

Question 1

6.02

What does Therapeutic Drug Monitoring (TDM) involve?

Answer 1

Routine clinical monitoring of plasma drug levels

(involves individualisation of dosage)

Question 2

6.02

What characteristic do the drugs which find TDM most useful have?

For what three anti-epileptics is TDM of most use?

Answer 2

TDM is most useful for drugs with a narrow therapeutic index.

(anti-epileptics, gentamicin, digoxin, lithium)

TDM is most useful for the anti-epileptics: carbamazepine, sodium valproate and phenytoin

Question 3

6.02

In what changed environmental circumstances (identify 2 scenarios) might TDM (Therapeutic Drug Monitoring) become particularly useful?

Answer 3

Pregnancy increases the metabolism of carbamazepine and phenytoin. Frequent dose adjustments are required during the pregnancy and post-partum.

Toxicity (ataxia, confusion, drowsiness)** **as a result of taking several anti-convulsants. TDM assists in determining which drug is causing the symptoms.

Question 4

6.02

What are the characteristics of some drugs which make TDM unhelpful in those circumstances?

Answer 4

1. Desired clinical endpoint can be measured e.g. anti-hypertensives –> blood pressure can be measured
2. Drugs that bind irreversibly have effects long after they can be detected in plasma
3. Parent drug has several active metabolites which contribute to net pharmacological activity. i.e. active metabolites occur after drug has left plasma?

Question 5

6.02

TDM stands for ….

Answer 5

Therapeutic Drug Monitoring