Pharmkinectics Flashcards
- dissolutin in stomach
- Absorption- into central compartment (duodenum-liver)
- Distributions- movement in tissue onto receptors (plasma)
- Biotranform/Metabolize - liver
- Elimination- urine bile
Five steps in time course of drug actions
Efficacy
determined by concentrate of drug at the receptor.
correlate w/ plasm drug levels
Absorbion, Distributin Elimination
LD, MD, Effect Drug concnetraion
What pharmacokinetics deals with (6 terms)
Routes of Drug Administration
IV Oral- swallow (po) Buccal- into cheek Sublingual-under tongue IM SC Inhalation- naxalone Transdermal-pathc Topical Rectal Intrthecal- spinal cord
ClearanceCL
Types of clearance
FActors the predict ratel of elimination
Mostly liver and kidney responsible for CL
Liver_lipid to water__now_kidney can clear__urine
Vol of fluid that would be cleared by drug/time
Fraction of unchanged drug reach plasm following admin of route of drug
IV F= 100%
Po F=5+%
Bioavailability F
Area under the curve AUC
F=AUC. AUC PO/AUC/IV dose
F IV= 100%
Drug exposure
Extent of absorbtion
First pass effect
portal blood system_liver 1st_ before entry into systemic circulation.
most of rx elimintated(depends on perfusion through organ
High isoniazid, morphin propanaol, verapamil, TCA
Rectal, sublinual, transdermal
Cocaine- if swallowed goes thru 1st pass. no brain, why snorts
assumption that ther is target concentrion for max effect which correlates to Cp (drug plasma levels)
Rational dosage regimens
Maintenance dose definition
does in should = dose out
does rate/F
Dose rate=Cl/Hr/Wt x target plasma [}
Dose rate/F
Cp does not correlates to therapeutic efficay and toxcity
Measure toxicity
Dose not related to efficacy
Lab will not do labs on TW 1-1000, impossible to OD
Monitor compliance
Change in cl rate d/t kidney or liver failure
Change in Vd d/t fluid, edem, acistes
half life change d/t age
Drug interaction
Therapeutic Drug Monitoring (TDM)
TDM what drugs to measure
low TI (digoxin) .5-2.0 Chonically used no s/s of toxictiy bio effects not easily measured Helps determine Target concentration Revise based on Cp
Passage of drugs across membranes (8 terms)
Ionized drugs (most drugs, water soluble) depend on ph environment. DO NoT cross membrane
Lipid soluble cross membrane-sone
Non IOn- lipid soluble- non polar, neutral
pka high for BASE
pKa low for ACID
Stomach PH 2, no absorbtion
Duondenum major site absorbtion
Drug absorption from stomach
Volume of distributionVd
concentration of drug in body/ {} of drug in Plasma
volume that would be necessary to contain the total amount of an administered drug at the same concentration that it is observed in the blood plasma.
Vd given
Plasm{} labs provide
Low Vd L means excreted in body, never entered organ, water soluble
5- only in plasma
5-20 ECF
20-40 total bodily fluid
>40 in deep tissue, lipid soluble
Which has greater pentration to deep tissue?