Core pharmacokinetic equations and biopharmaceutics concepts tested on the NAPLEX, as cloze cards with variables defined.
About this set
38 cloze cards for NAPLEX NAPLEX. It opens with "The elimination half-life (t1/2) of a drug equals ____, where Vd is volume of" and "Volume of distribution (Vd) is calculated as ____, where C0 is the initial". More Healthcare and Nursing decks are listed below.
38 cards · cloze cards · AI-written, checked twice. Edit anything.
- The elimination half-life (t1/2) of a drug equals ____, where Vd is volume of distribution and CL is clearance.
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0.693 x Vd / CL- Volume of distribution (Vd) is calculated as ____, where C0 is the initial plasma concentration extrapolated to time zero.
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Dose / C0- In first-order elimination kinetics, the rate of drug elimination is ____.
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directly proportional to the plasma drug concentration- In zero-order elimination kinetics, a ____ of drug is eliminated per unit time, regardless of concentration.
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constant amount- In first-order elimination kinetics, a constant ____ of drug is eliminated per unit time.
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fraction (percentage)- How many half-lives are typically required to reach steady-state drug concentration?
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About 4 to 5 half-lives- The loading dose formula is LD = ____, where Cp is the target plasma concentration and F is bioavailability.
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(Vd x Cp) / F- The maintenance dose formula is MD = ____, where Css is the target steady-state concentration and tau is the dosing interval.
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(CL x Css x tau) / F- Oral bioavailability (F) is calculated as ____ for equal doses.
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AUC(oral) / AUC(IV)- What is the first-pass effect?
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Metabolism of an orally absorbed drug by the liver (or gut wall) before it reaches systemic circulation- Hepatic extraction ratio (ER) equals ____, where Ca is drug concentration entering and Cv is drug concentration leaving the liver.
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(Ca - Cv) / Ca- For a drug with a high hepatic extraction ratio, oral bioavailability is most limited by what factor?
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Hepatic blood flow- Michaelis-Menten (saturable) kinetics is described by the equation dC/dt = ____.
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-Vmax x C / (Km + C)- Name a classic drug that exhibits Michaelis-Menten (nonlinear) elimination kinetics at therapeutic doses.
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Phenytoin- The therapeutic index (TI) is calculated as ____, comparing the toxic dose to the effective dose in 50% of a population.
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TD50 / ED50
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