Pharmacokinetics Language English Format: PDF Price - Tutorsindia

More documents

Recommendations

Info

<strong>Pharmacokinetics</strong>Constant intravenous infusionLD = Target x V / (F x S)= 15mg/L x 28.8L / (1.0 x 0.7)= 617mgCss = Rinf / ClRinf (theophylline) = Css x Cl= 15mg/L x 2.4L/h= 36mg/hRinf (aminophylline) = 36mg/h / S= 36mg/h / 0.7= 51mg/h8.4.3 Loading dose where we have to recognize two compartmentsThe method of calculation of a loading dose shown above, works fine if the drug can be considered as occupying onecompartment. However, some drugs have to be recognized as occupying two compartments and then there is a potentialproblem. Figure 8.4 shows the situation. Both the loading dose and the continuing infusion act as inputs.Please click the advertWELCOME TOOUR WORLDOF TEACHING!INNOVATION, FLAT HIERARCHIESAND OPEN-MINDED PROFESSORSSTUDY IN SWEDEN– HOMEOF THE NOBEL PRIZECLOSE COLLABORATION WITH FUTUREEMPLOYERS SUCH AS ABB AND ERICSSONSASHA SHAHBAZILEFT IRAN FOR AMASTERS IN PRODUCTAND PROCESSDEVELOPMENT ANDLOTS OF INNEBANDYHE’LL TELL YOU ALL ABOUT IT ANDANSWER YOUR QUESTIONS ATMDUSTUDENT.COMwww.mdh.seDownload free ebooks at bookboon.com78
<strong>Pharmacokinetics</strong>Constant intravenous infusionLDR infV 1V 2EliminatedFigure 8.4 Infusion accompanied by a loading dose with a two compartment system.The formula for calculating a loading dose takes account of the volume of distribution. But that raises the question, whichvolume? Should we use just V 1or the complete volume of the system Vss (i.e. V 1+ V 2)?If we use the total, V 1+ V 2, we will arrive at a dose large enough to raise the concentration of the whole system to thetarget concentration. However, that dose will initially find itself constrained within just V 1and therefore the initialconcentration will be much higher than the target. The loading dose will eventually redistribute throughout the completevolume and drug concentrations will decline. Whether the initially high levels are a real problem depends upon howquickly the loading dose disperses and the potential of the drug to cause toxicity over the period prior to re-equilibration.For some drugs such as lidocaine, the problem is perfectly real and a loading dose calculated using the complete volumeof the system would risk toxicity.If alternatively, we calculate the loading dose using just V 1, then the initial concentration in the first compartment (includingblood levels) should match the target concentration. This is shown in Figure 8.5, where it is assumed that the targetconcentration is 4mg/L and that the shaded area (3-5mg/L) is the acceptable concentration range. Immediately after theinjection, there will be a marked disequilibrium, with the whole dose in the first compartment and drug will move out ofthe first into the second compartment. This will cause the drop in concentrations shown in the early part of the graph.After a while enough drug will have moved over to the second compartment to achieve an equilibrium. Distributionalloss of drug from the first compartment will then cease and the infusion will be able to return the concentration to Css.79Download free ebooks at bookboon.com
Page 2 and 3:
Philip RowePharmacokineticsDownload
Page 4 and 5:
PharmacokineticsContentsContentsInt
Page 6 and 7:
PharmacokineticsContents7.3 Determi
Page 8 and 9:
PharmacokineticsContents13 Computer
Page 10 and 11:
PharmacokineticsADME and Pharmacoki
Page 12 and 13:
PharmacokineticsADME and Pharmacoki
Page 14 and 15:
PharmacokineticsAbsorption: Absorpt
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
PharmacokineticsDistribution: Compa
Page 26 and 27:
PharmacokineticsDistribution: Compa
Page 28 and 29: PharmacokineticsDistribution: Compa
Page 38 and 39: PharmacokineticsElimination: Elimin
Page 48 and 49: PharmacokineticsSingle intravenous
Page 56 and 57: PharmacokineticsAnalysis of experim
Page 74 and 75: PharmacokineticsConstant intravenou
Page 84 and 85: PharmacokineticsExtravascular admin
Page 94 and 95: PharmacokineticsMultiple dosing10 M
Page 96 and 97: PharmacokineticsMultiple dosing1614
Page 98 and 99: PharmacokineticsMultiple dosingIn c
Page 100 and 101: PharmacokineticsMultiple dosingCss,
Page 102 and 103: PharmacokineticsMultiple dosing1614
Page 104 and 105: PharmacokineticsMultiple dosing10.6
Page 106 and 107: PharmacokineticsMultiple dosing76Co
Page 108 and 109: PharmacokineticsMultiple dosing5. A
Page 110 and 111: PharmacokineticsNon-linear pharmaco
Page 116 and 117: PharmacokineticsNon-compartmental p
Page 118 and 119: PharmacokineticsNon-compartmental p
Page 120 and 121: PharmacokineticsComputerized analys
Page 126 and 127: PharmacokineticsCreatinine clearanc
Page 128 and 129:
PharmacokineticsCreatinine clearanc
Page 130 and 131:
PharmacokineticsPharmacokinetic sym
Page 132 and 133:
PharmacokineticsPharmacokinetic sym
Page 134 and 135:
PharmacokineticsAdditional material
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
show all

Pharmacokinetics Language English Format: PDF Price - Tutorsindia

Create successful ePaper yourself

Delete template?

Save as template?