Clinical Pharmacokinetics Flashcards
Order of kinetics ?
1.First order -Exponential kinetics
2.Zero order -Saturation kinetics
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First order kinetics Details ?
( Rates of ABSORPTION , Distribution, Metabolism , Excretion —- Proportion — Conc of the body )
Rate of metabolism(V) = Vmax x [C]/ Km x [C]
Michaelis-Menten kinetics
80mg——–40mg——-20mg———10mg————5mg—–2.5mg
50% excreted
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Zero order kinetics ?
( Rates of ABSORPTION , Distribution, Metabolism , Excretion —- NOT (XXXXX)— Proportion — Conc of the body )
Rate of metabolism(V) = Vmax x [C]/ Km x [C]
A FIXED amount is metabolized
80mg—70mg—-60mg—–50mg———–
10mg=FIXED AMOUNT
1ST ORDER drugs ?
- low dose aspirine
- low dose phenytoin
- carbamazepine
- phenobarbitone
- paracetamol
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Zero order drugs ?
- high dose aspirine
- high dose pheytoin
- ethanol
- warfarin
- tolbtamide
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Types of half life <
plasma
elimination
biological
Half life defiantion ?
it is the time
to change the amount of the drug
in the body by one half
during elimination
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proportionate relationship with Half life ?
distribution
Vd = volume of distribution
D +++++++
HL ++++++++
route of administration & Hlaf life >
SC > IM > Oral > IV
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Ulta relationship with half life >
absroption
biotransformation
drug excretion
era +++++++++++++
half life ————————–
T 1/2 = 12 hours
what are the information’s ?
PPB more
Absoprtion
metabolism
action
excretion
ei 4 ta — slow
patient compliance - Good
Solubility & Absorption ?
inc lipid solubility — inc A
inc water solubility — dec A
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solubility & distribution ?
lipid soluble —- D intracellularly
water soluble —- D extracellularly
Biotransformation & S ?
more lipid soluble more bio-transformation
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Drug excretion & solubility ?
more lipid s==== more absorbed
more water soluble ==== more excreted
