Pharmacokinetics II Flashcards
What are the major body compartments
extracellular fluid, intracellular fluid, transcellular fluids, fat
Which type of drugs are effective
free drugs
What type of drugs does fat have an important impact on
lipophilic drugs
What is drug distribution based on
permeability and lipid solubility
What is meningitis
bacterial infection of the CNS
What is domperidone
antagonist of dopaminergic agonist receptors in chemoreceptor trigger zone
What regulates drug access to the CNS
blood brain barrier
Describe a junction in the CNS
endothelial cells line blood vessels and form tight junctions
What are tight junctions impermeable to
water soluble molecules
What can cross the BBB easily
lipid soluble molecules - ethanol and caffeine
What can happen to tight junctions during inflammation
become leaky
What can meningitis be treated with
iv penicillin
What other factors can influence drug distribution and elimination
binding to plasma proteins, partition into specific tissues
What does albumin bind to
mainly acidic drugs
What are the two main biochemical reactions for drug metabolism
catabolic reactions, synthetic (anabolic) reactions
What do catabolic reactions produce
more reactive compounds
What do anabolic reactions involve
conjugation
What do anabolic reactions produce
inactive product
Where does drug metabolism occur
liver
What affect can metabolism have on drug action
alter or prolong pharmacological drug action
What must drugs cross in order to be metabolised
plasma membrane
What speeds up drug metabolism
microsomal enzymes - cytochrome p450 in the liver
What are the stages of aspirin elimination
drug forms a derivative - then forms a conjugate
How can a drug form a derivative
oxidation, hydroxylation, dealkylation, deamination, hydrolysis
