DRUG METABOLISM
TWO IMPORTANT EFFECTS:
1. The drug is made more HYDROPHILIC
HASTENS the excretion by the kidneys
Less-lipid soluble metabolite is not readily reabsorbed in
the renal tubules
2. The metabolites are usually LESS ACTIVE than the
parent drug
THE LIVER IS NB!
2 GENERAL TYPES OF REACTION:
PHASE 1 reactions PHASE 2 reactions
BIOTRANSFORMATION of drugs Drugs are made more
to a MORE POLAR metabolite HYDROPHILIC
Introducing/unmasking a CONJUGATION with
functional group (-OH, -NH2, -SH) endogenous compounds in
Oxidation = most common
the LIVER
Catalyzed by MIXED FUNCTION
OXIDASES (Cytochrome P450) TYPES OF CONJUGATION
VERY LOW substrate specificity Glucoronide
TWO IMPORTANT EFFECTS:
1. The drug is made more HYDROPHILIC
HASTENS the excretion by the kidneys
Less-lipid soluble metabolite is not readily reabsorbed in
the renal tubules
2. The metabolites are usually LESS ACTIVE than the
parent drug
THE LIVER IS NB!
2 GENERAL TYPES OF REACTION:
PHASE 1 reactions PHASE 2 reactions
BIOTRANSFORMATION of drugs Drugs are made more
to a MORE POLAR metabolite HYDROPHILIC
Introducing/unmasking a CONJUGATION with
functional group (-OH, -NH2, -SH) endogenous compounds in
Oxidation = most common
the LIVER
Catalyzed by MIXED FUNCTION
OXIDASES (Cytochrome P450) TYPES OF CONJUGATION
VERY LOW substrate specificity Glucoronide
