Flashcards in 0403 - Clinical pharmacology - kinetics, doses, interactions, adverse effects - EG Deck (17):
Compare clinical pharmacology to therapeutics
Clinical pharmacology is about the principles behind the prescribing process, effects in human organism most particularly, therapeutics is the process of medical treatment
List some of the unique aspects of a patient's profile that need to be taken into consideration when considering a drug and dosing regime.
age, weight, sex, race, allergies, smoking history, alcohol history, diseases, pregnant/lactating, current therapy, intelligence.
List some of the aspects of a drug profile.
name, class, action, pharmacokinetics, indications, contraindications/precautions, interactions, side effects, dosing regimen, monitoring, overdose.
study and description of mechanism of action of a drug
study and description of handling of a drug in and by the body
study of inheritance and influence of genetics on drugs and drug action
Define drug clearance.
Drug clearance is the volume of plasma (or blood in some cases) cleared (i.e. from which the drug has been completely remove) per unit time.Usually expressed as L/h.
What does drug clearance determine?
The maintenance dose of the drug.The maintenance dose rate is the dose per time required to maintain the plasma (or blood) concentration. The "steady state".
Define the volume of distribution.
The total volume in the body into which the drug appears to be distributed with a concentration equal to that of plasma.Expressed as mg/L.
What does the volume of distribution determine?
The loading dose of a drug.
Define the half life of elimination of a drug.
The half life of elimination is the time for the concentration of the drug in plasma or blood (or amount of drug in body) to halve.Expressed in units of time (usually hours).
What does the half life of elimination determine?
The dosing interval.
The fraction of a drug which reaches the systemic circulation from defined route of administration.Parental = 100%oral is variable
What are P-glycoproteins?
drug transporters, membrane efflux pumps. Specific proteins identified in cells whose activity is linked to explaining the variable bio-availability of some drugs as well as access to selected compartments.
What are some of the functions of P-glycoproteins?
- limiting absorption from the gut- blood-brain barrier- ovarian, testicular, adrenal cortex protection- hepatic and renal excretion- protecting fetus
What pathologies of the liver are particularly important in pharmacokinetics?
Primary Liver problems:- decreased enzyme capacity- decreased blood flow to liver lobules- decreased liver blood flow per se.- decreased drug transportersSecondary Liver problems:- bilirubin- circulating proteins