Therapeutic Drug Monitoring
Also written as TDM.
You are required to put together a tutorial on therapeutic drug monitoring.
What our notes say
- You are required to put together a tutorial on therapeutic drug monitoring. (hsd sept21 clin chem saqs essay and case studies papers final exam papers — Past)
- Vancomycin is the drug of choice for MRSA but carries risks of red man syndrome, nephrotoxicity, and ototoxicity; therapeutic drug monitoring is essential. (Pharmco Notes)
- Therapeutic drug monitoring for agents with narrow therapeutic index (e.g., aminoglycosides, vancomycin). (Antimicrobial selection, stewardship and resistance)
- Therapeutic drug monitoring: azathioprine/6‑MP metabolites, anti‑TNF trough levels when loss of response suspected. (Inflammatory bowel disease)
- Limited laboratory monitoring (e.g., lack of therapeutic drug monitoring for aminoglycosides). (Clinical pharmacology and rational prescribing)
- | Therapeutic drug monitoring (e.g., antiretroviral trough levels) | Adequacy of drug exposure | Sub‑therapeutic → risk of resistance; supra‑therapeutic → toxicity | (Clinical pharmacology and rational prescribing)
Study material on Therapeutic Drug Monitoring
- Chemical Pathology Practice Examination
- Clinical pharmacology and rational prescribing
- Chemical Pathology
- Chemical Pathology MCQS
- Weekly Pharmacology Exam - April 21, 2026 (Section A: MCQs)
- CHEMICAL PATHOLOGY MCQs
Practice questions on Therapeutic Drug Monitoring
Therapeutic Drug Monitoring (TDM) of vancomycin is used to prevent which complications while ensuring efficacy?
- QT prolongation
- Bone marrow suppression
- Hepatotoxicity
- Nephrotoxicity and ototoxicity
Answer: D. Vancomycin trough monitoring (or AUC/MIC-guided dosing) is crucial to avoid nephrotoxicity (associated with high levels) and ototoxicity, while ensuring the drug concentration is sufficient for efficacy (preventing sub-therapeutic levels).
Therapeutic drug monitoring (TDM) is most useful for drugs with
- Wide therapeutic index
- Narrow therapeutic index
- Zero-order kinetics only
- Rapid hepatic clearance
Answer: B. TDM is indicated for narrow therapeutic index drugs like digoxin, phenytoin, lithium.
Therapeutic Drug Monitoring (TDM) is usually NOT required for:
- Digoxin
- Penicillin
- Phenytoin
- Lithium
Answer: B. Penicillin has a very high therapeutic index and wide safety margin.
Therapeutic drug monitoring (TDM) is most important for drugs with
- Wide therapeutic index and predictable pharmacokinetics
- Narrow therapeutic index where small dose changes cause toxicity or treatment failure
- No renal excretion and stable metabolism
- Short half-lives only requiring single dose monitoring
Answer: B. TDM is indicated for: narrow therapeutic index drugs (digoxin, lithium, phenytoin, gentamicin, vancomycin, cyclosporine, theophylline), drugs with unpredictable pharmacokinetics, drugs where toxicity mimics the disease being treated, monitoring compliance, and dose adjustment in renal/hepatic failure.