L42 IV Bolus 2

• Apparent volume of distribution (V)

  The volume into which a drug distributes in the body at equilibrium
• V


  • Used for relating A & Cp
  • Estimating the dose required to achieve a given concentration
• Loading dose


  In the one compartmental model, the volume of the compartment equals the volume of distribution
• Equilibrium of distribution achieved at t=0 in one compartment distribution
• Clearance (Cl)


  Proportionality factor relating the rate of drug elimination (dA/dt) to the plasma drug concentration
• Elimination half-life (t_1/2)


  Time required for the drug concentration (and amount of drug) in the body to fall by one-half
• Area Under the Curve (AUC)

  Used to express the 'body exposure' to the drug as a link to therapeutic and toxic response, determine the clearance of a drug, estimate the bioavailability of an extravascular formulation, assess the bioequivalence of two formulations
• AUC is the preferred method to estimate clearance because it is model independent
• Estimating the Area Under the Curve (AUC)

  1. Trapezoidal rule from t=0 to t=n

  2. AUC_n = c_n/k
• Bioavailability


  Ratio of the AUC obtained with an extravascular formulation and AUC_IV (AUC obtained with IV administration of the same dose)