General pharma
Phase 2 metabolism
Conjugation reactions in which a polar molecule is linked to a suitable functional group on a drug or one of its Phase 1 metabolites. morphine-6-glucorinde much more potent, fluoxetine TO S-norfluoxentine 10 day half life
enteric coated for drugs
Omeprazole, lansoprazole
vancomycin given which way for clostridium difficile
Oral, not absorbed via small intestines, goes to colon
Phase 1 metabolism
Oxidation, reduction, hydrolysis
Distribution phase
The phase of drug movement from the site of administration into the tissues, factors are CO, capillary permeability, binding to plasma protein, lipophilicity
first order
constant fraction of the drug is eliminated per unit of time
Vd
defined as the fluid volume that is required to contain the entire drug in the body at the same concentration measured in the plasma
effect of Vd of drug half-life
delivery of drug to organs of elimination depends not only on blood flow but also on the fraction of the drug in the plasma, very large Vd most of the drug is in extrplasmic space and unavailable to reach excretory organs, factor increasing Vd can increase half-life and duration of action of the drug .
inhibitor of CYP
ketoconazole, omeprazole, erythromycin, Ritonavir
highest bioavailability routes
parental route
CYP2C9/10 inducers
phenobarbital , rifampin
Inducers of CYP3a4/5
phenobarbital, phenytoin rifampin, dexamethasone carbamazepine, st,jOHNS WART
P-glycoprotien
pump drugs out of cell, reduces drug absorption, multi drug resistance, melanoma
bioavailability
rate and extent to which a drug reaches the systemic circulation, Iv 100%, AUC (AREA under the curve)
the pKa is a measure of
the strength of the interaction of a compound with a proton, the lower the ... the more acidic, higher the ...more basic
A drug passes if its more readily ..
uncharged, non ionised
Drug clearance
hepatic metabolism, biliary and renal, (lung excretion)
zero order kinetics
few drugs, aspirin, ethanol, phenytoin, doses are very large, therefore C is much greater than Km and velocity equation becomes Vmax*{c}/C =Vmax