PHARMACOKINETICS 1 Flashcards
A KEY DETERMINANT OF THE EFFECTIVENESS AND USEFULNESS OF A DRUG DEPENDS ON ACHIEVING THE CORRECT ………..
CONCENTRATION
WHAT ARE THE THINGS THAT AFFECT DRUG CONCENTRATION
MECHANISM OF ACTION OF THE DRUG
THE DRUG TARGET
THE PHYSICOCHEMICAL PROPERTIES OF THE DRUG
BODILY PROCESSES
WHAT BODILY PROCESS AFFECTING DRUG CONC
ABSORPTION
DRISTRIBUTION
METABOLISM
EXCRETION
WHAT CAN BE SAID ABOUT THE CONCENTRATION OF A DRUG THROUGHOUT THE BODY
THE CONCENTRATION WILL REACH A CONSTANT BUT THIS CONSTANT WILL BE DIFFERENT ACROSS BODILY COMPARTMENTS
WHAT DIFFERENT BODY COMPARTMENTS ARE THERE
PLASMA ISF LYMPH FAT IC FLUID TRANSCELLULAR FLUID
HOW DO DRUGS MOVE BETWEEN COMPARTMENTS
VIA BARRIERS
HOW CAN DRUGS MOVE ACROSS BARRIERS
DIFFUSION THROUGH THE BILAYER
DIFFUSION THROUGH CHANNELS
CARRIERS
PINOCYTOSIS
WHAT IS THE PARTITION CO-EFFICIENT
THIS IS A MEASURE OF LIPID SOLUBILITY
IE THE HIGHER THE CO-EFFICIENT THE MORE EASILY DIFFUSIBLE IN LIPIDS
NON POLAR MOLECULES DISSOLVE ………………… IN LIPIDS AND PENETRATE CELL ……………………… FREELY. THIS MEASURE THAT THERE IS AN ………………….. RATE OF GUT ABSORPTION AS WELL AS PENETRATION INTO BRAIN AND TISSUES AS WELL AS ……………………… EXRETION.
FREELY
MEMBRANES
INCREASED
RENAL
DIFFUSION IS ……………………. TO THE SIZE OF THE DRUG
PROPORTIONAL
WHAT ARE THE ROUTES OF ADMINISTRATION
ORAL/RECTAL PERCUTANEOUS INTRAVENOUS INTRAMUSCULAR INTRATHECAL INHALATION
WHAT IS THE FASTEST ROUTE OF ADMINISTRATION
INTRAVENOUS
WHERE IS THE MORE COMMON SITE OF ADMINISTRATION FOR BIOLOGICS AND WHY
INTRAMUSCULAR
TO ESCAPE METABOLISM
WHAT IS INTRATHECAL
DIRECTLY IN CSF
WHAT IS BIOAVAILABILITY
FREE CONC OF DRUG IN PLASMA/THE AMOUNT OF DRUG TAKEN
WHAT FORM DO DRUGS COME AS USUALLY
SALTS FROM WEAK ACIDS AND BASES
WHAT IS PKA
A DISSOCIATION CONSTANT THAT DESCRIBES THE RATIO OF DISSOCIATED TO NON DISSOCIATED FORM OF ACID AT DIFFERENT PH
WHAT IS THE FORMULA FOR AN ACID
HA ——- H+ + A-
THE NON DISSOCIATED FORM OF ACID (HA) IS WHAT
NON POLAR (THEREFORE WOULD DIFFUSE EASILY)
THE DISSOCIATED FORM OF ACID (H+ + A-) IS WHAT
POLAR (THEREFORE WILL NOT DIFFUSE AS EASILY)
HOW TO WE CALCULATE PKA
PKA= PH + LOG([HA]/[A-])
IF THE PKA WAS 3 WHAT DOES THIS ACTUALLY TELL US
3 TIMES MORE OF THE DRUG DIGESTED WILL BE IN UNDISSOCIATED FORM THAT DISSOCIATED FORM AND THEREFORE WILL DIFFUSE WELL
WEAK ACIDS IN AN ACIDIC ENVIRONMENTS (IE LOW PH) TEND TO …………………. PKA. IF PKA IS ……………. THEN MORE OF THE DRUG WILL BE IN ………………….. FORM
DECREASE
LOWER
NON DISSOCIATED
WHAT HAPPENS TO WEAK ACIDS IN MORE ALKALINE ENVIRONMENTS
THE PKA INCREASES
MORE OF THE DRUG WILL BE IN DISSOCIATED FORM AND THEREFORE CANNOT DIFFUSE WELL BETWEEN COMPARTMENTS
THE CONCENTRATION WILL THEN BUILD IN THAT COMPARTMENT (TRAPPED)
EXPLAIN ONE WAY IN WHICH MORE ALKALINE ENVIRONMENTS FOR DRUGS CAN BE DANGEROUS AND ONE WAY IN WHICH IT CAN BE HELPFUL
ACCUMULATION OF DRUGS IN A COMPARTMENT CAN CAUSE TOXICITY
ALKALINISATION OF THE URINE MEANS HIGHER DISSOCIATED FORM FOR DRUG EXCRETION IN THE CASE OF POISONING
HOW CAN YOU ALKALINISE URINE FOR USE IN TREATMENT OF POISONING
NAHCO3
WHEN CONSIDERING TRANSPORTERS AS A MEANS OF DIFFUSION WHAT CAN AFFECT DRUG CONCENTRATION
GENETIC VARIATION/POLYMORPHISMS IN TRANSPORTERS
WHAT IS AN EXAMPLE OF A POLYMORPHISM IN A TRANSPORTER THAT AFFECTS DRUG CONCENTRATION
OCT1 TRANSPORTER ARE ASSOCIATED WITH DIFFERENT RESPONSES TO METFORMIN IN HEALTHY HUMANS AFFECTING ABILITY TO MAINTAIN BLOOD SUGAR LEVELS
WHAT IS METFORMIN USED FOR
TREATMENT OF DIABETES TYPE 2
