UBC Faculty Research and Publications

Simple clinical pharmacology can improve prescribing University of British Columbia. Therapeutics Initiative


Therapeutics Letter 142 explores pharmacokinetics principles that can help clinicians prescribe efficiently and avoid common problems. Conclusions: Knowing Tmax can suggest when to assess symptomatic effects of a drug (good or bad). Allowing 4 to 5 half-lives predicts steady state effects of drugs taken for symptoms. When a drug is stopped, expect effects to dissipate or potential withdrawal symptoms to emerge after a similar interval. Some half-lives reported as means have significant inter-individual ranges. Patients who report shorter or longer duration of effects than expected may have different elimination kinetics. “Steady state” seldom applies in sick people. Acute decline in kidney function or saturated liver metabolism can cause dangerous toxicity: e.g., K+, lithium, gabapentin, pregabalin, acetaminophen, phenytoin, alcohol.

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International