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PCB Pharmacist Registration study materials
PCB Pharmacist Registration study resources

PCB Pharmacist Registration: Pharmacology and Toxicology

PCB Pharmacist Registration · Work through your exam, one topic at a time.

All guide sections

Pharmacology and Toxicology

Core Concepts

Pharmacology studies drug action: pharmacodynamics (receptors, dose-response, agonists/antagonists) and pharmacokinetics (ADME: absorption, distribution, metabolism, excretion). Candidates must understand receptor types (GPCRs, ion channels, enzymes, transporters), signal transduction, and dose-response curves (ED50, LD50, therapeutic index). Toxicology covers adverse effects, antidotes, and poisoning management.

Question Traps

  • Agonist vs. antagonist: Full agonists produce maximal response; partial agonists produce submaximal response even at full occupancy; antagonists have affinity but no efficacy.
  • Therapeutic index (TI): TI = LD50/ED50. A narrow TI means safer dosing requires monitoring (e.g., digoxin, warfarin).
  • First-order vs. zero-order kinetics: First-order elimination is proportional to plasma concentration (most drugs); zero-order (saturation) eliminates at a constant rate (e.g., ethanol, phenytoin at high doses).

Worked Example / Rule of Thumb

Question: A drug has ED50 = 5 mg and LD50 = 50 mg. What is the therapeutic index? TI = 50/5 = 10. Rule of thumb: Higher TI = safer drug. For narrow-TI drugs, use therapeutic drug monitoring.