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Flashcards in Math equation stuff for pharm Deck (12):
1

pharmacokinetics vs. pharmacodynamics

kinetics: effects of the body on the drug: absorption, distribution, metabolism, excretion (ADME)
dynamics: effects of the drug on the body: receptor binding, drug efficacy, potency, toxicity

2

bioavailability

the fraction of the administered drug that reaches the systemic circulation unchanged. usually 100% for an IV drug and less than 100% for an oral drug d/t incomplete absorption and first-pass metabolism

3

volume of distribution; effects of liver/kidney disease on Vd

Vd = amt of drug in the body/plasma drug concentration. measures distribution to other compartments. liver and kidney disease may incr. the Vd the Vd because of decr. protein binding

4

low Vd: compartment, drug types

low Vd means most of the drug is in the blood. usually seen in drugs that are larged, charged, or protein-bound

5

medium Vd: compartment, drug types

drug in the ECF. seen with small hydrophilic molecules

6

high Vd: compartment, drug types

compartment: all tissues, incl. fat
seen in small lipophilic molecs, esp. if bound to tissue protein

7

half life: equation.

half life = (0.7 X Vd)/clearance

8

How many half lives to reach steady state?

4-5 half lives; 3.3 to reach 90% of steady state

9

clearance

CL = rate of elim of a drug/ plasma drug conc = Vd X Ke (elimination constant) = (.7 X Vd)/half life
in words, this is the vol. of plasma cleared of drug per unit time. may be impaired with defects in cardiac, hepatic, or renal function

10

loading dose

(Cp X Vd)/F. Cp is the target plasma concentration at steady state. F = bioavailibility.

11

maintenance dose

(Cp X clearance X dosage interval if not continuous)/ bioavailability

12

effect of renal and liver disease on maintenance dose and loading dose

typically maintenance dose is decr. but loading dose is not changed.