· The drug in question has a narrow therapeutic range, eg: Lithium, phenytoin, and digoxin
· A direct relationship exists between the drug or drug metabolite levels in plasma and the pharmacological or toxic effects,
· The therapeutic effect can not be readily assessed by the clinical observation,
· Large individual variability in steady state plasma concentration exits at any given dose
· Appropriate analytic techniques are available to determine the drug and metabolite levels
· Drugs for which relationship between dose and plasma concentration is unpredictable, e.g Phenytoin
· Non compliance
· Therapeutic failure
· Major organ failure
· Prevention of adverse drug effects
Wells BG, DiPiro J, Schwinghammer T (2013), Pharmacotherapy Handbook (6th Ed). New York, NY: McGraw-Hill.
DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008): Pharmacotherapy: A Pathophysiologic Approach (7th ed): New York, NY: McGraw-Hill.
Katz M D., Matthias KR., Chisholm-Burns M A., Pharmacotherapy(2011) Principles & Practice Study Guide: A Case-Based Care Plan Approach: New York, NY: McGraw-Hill.
Schwinghammer TL, Koehler JM (2009) Pharmacotherapy Casebook: A Patient-Focused Approach (7th ed): New York, NY: McGraw-Hill.