Metabolism Of and pharmokinetics Flashcards
What is drug metabolism?
Biochemical modification of pharmaceutical substances by living organisms is using enzymatic activity
Factors which affect metabolism
Drugs/ herbal substances Genetics Hepatic blood flow Liver disease Age Sex Ethnicity Pregnancy
Enzyme induction
Important drug metabolising enzymes induced by other compounds
Involves increased synthesis and increased activity
Decreased amount of drugs in the blood.
Most common include smoking
use of St. John’s
Depression
Enzyme initiation vs induction
Initiation takes ages
Inhibition very quick
Inhibition through herbs, food, medicines etc
Grapefruit juice
Huge enzyme inhibitor
Blood pressure lowered hugely
Can be beneficial in some case,s can also be harmful
Decreases intestinal
Statins
Cause breakdown of muscles
Genetic variation in response to drugs
Wide variability in response to drugs between individuals
Pharmacogenetics
Drug metabolising enzymes expressed in many different forms
Lack or decreased activity of an enzyme results in DRUG TOXICITY
4 subpopulations of metabolisers
Poor metabolisers
Intermediate metabolisers
Extensive metabolisers
Ultra rapid metabolisers
Metabolism of adolescents
Much higher than adults
Child may lose control of medication when reaching puberty
4 pharmokinetic areas
Absorption, distribution, metabolism, elimination
Differences in gender
Certain enzymes - women have more enzyme activity, and vice versa
Pharmokinetics in elderly
Lots of drugs inhibit enzyme activity
Decrease
Major ethnic variety
In pharmakinetics
