50. Therapeutic drug monitoring (TDM)
= measurement of drug concentration or activity in plasma
- Methods
- High performance liquid chromatography
- Immunoassay
- Indications
- Non-linear kinetics of drug
- When there is poor compliance
- If the therapeutic effect can’t be assessed clinically
- If the therapeutic index is low
- Warfarin
- Aminoglycosides
- Antipsychotics
- Digoxin
- Lithium
- When there are signs of overdose
- To determine pharmacokinetic interactions