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16 Cards in this Set
- Front
- Back
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Loading Dose =
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CpVd
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Dir (infusion rate) =
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CssCl (steady state concentration, clearance)
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Clearance =
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KeVd
Units are L/Kg(hr) |
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Ke =
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ln2/halflife The elimination rate constant. ln2 = 0.693
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half life =
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0.693/ke ln2 = 0.693
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Dm (maintenance dose) =
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Cavg(Cl)(Td) = CssCl(Td) units will be mg/kg
If Oral administered becomes: Cavg(Cl)(Td)/F |
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units of clearance?
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Cl = L/Kg(hr) = Vd(Ke)
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units of volume distribution?
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Vd = L/Kg
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If you have a large half life what will the Ke be?
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Smaller, they have an inverse relationship.
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If you have a large Ke what will the half life be?
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Smaller, they have an inverse relationship.
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If you are given an infusion rate for a long half-life drug, how can you give a loading dose to bring the concentration up?
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Loading Dose = Dir/Ke
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Loading dose with bioavailability and salt form considered.
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Dl = CpVd/(F)(S)
F is 1 intravenously or less orally, and S is 1 or less if in a salt form. |
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What is Tmax equal to?
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It is the time of Peak plasma concentration occurs following an oral dose. Tmax = Ln(Ka/Ke)/(Ka-Ke)
Or when Ka = Ke, then Tmax = 1/Ka = 1/Ke |
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What is Zero Order Kinetics?
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There is no excess of enzymes, so the system is saturated. Only dependent on the rate of the elimination by enzymes. Not affected by concentration of the drug, only Vmax.
Equation: KC`0 = K (the rate constant). |
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What is Michaelis-Menton Kinetics?
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Capacity-limited transition kinetics between zero and first order. As concentrations decrease from saturated zero order, toward first-order kinetics at low concentrations.
Equation: Vmax(C)/Km(C) Km = concentration when the reaction occurs at half the maximal velocity. |
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What is First Order Kinetics?
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This is when absorption and elimination processes have rates that are dependent on concentration.
Equation: KeC`1 = KeC |
