chap 4 Flashcards
(42 cards)
___consists of 4 basic processes…absorption, distribution, metabolism and excretion
pharmacokinetics
_______drugs ionize in basic alkaline media whereas ______drugs ionize in acidic media
acidic
basic
____is defined as the movement of a drug from its site of administration into the blood
absorption
_____is enhanced by rapid drug dissolution, high lipid solubility of the drug, a large surface area of absorption and high blood flow at the site of administration
absorption
____ administration has several advantages rapid onset, precise control over the amount of drug entering the blood, suitability for use with large volumes of fluid, and suitability of irritant drugs
Intravenous
to move around the body , drugs must cross____ either by passing thru pores, undergoing transport, penetrating the membrane directly
membranes
____ processes determine the concentration of a drug at its sites of action, and thereby determine the intensity and time course of responses.
pharmacokinetic
____administration has several disadvantages, high cost, difficulty, inconvenience, danger because of reversibility, potential for fluid overload, infection and embolism
Intravenous
___administration has 2 advantages suitability for insoluble drugs and for depot preparations
Intramuscular
____administration has 2 disadvantages inconvenience and discomfort.
intramuscular
__administration has the same advantages and disadvantages as intramuscular administration
subcutaneous
___administration has the advantages of ease, convenience, economy and safety
Oral
____ administration disadvantages are high variability, possible inactivation by stomach acid, digestive enzymes, liver enzymes( because ____ must pass thru liver before reaching general circulation
oral
oral
____ is defined as the movement of drugs thru out the body
distribution
In most____drugs can easily leave the vasculature thru spaces between cells that compose the capillary wall
tissues
The term _____refers to the presence of tight junctions between the cells that compose capiilary walls in the
CNS. so drugs must pass thru the cells of the capillary wall, rather than between them, to reach the CNS
blood brain barrier BBB
the membranes to the ____ do not constitute an absolute barrier to the passage of drugs.
placenta
Many drugs bind reversibly to___ . while bound to ____ drug molecules cannot leave the vascular system.
plasma albumin
albumin
____is defined as the enzymatic alteration of drug structure
drug metabolism (biotransformation)
Most drug metabolism takes place in the ___ and is catlyzed by the cytochrome P450 system of enzymes
liver
The most importance consequence of ___ ___ is promotion of renal drug excretion by converting lipid soluable drugs into more hydrophillic forms
drug metabolism
Drugs that are metabolized by P450 enzymes are called ___
substrates
The rate at which ___ are metabolized is affected by drugs that act as P450 inducers or inhibitors
substrates
Drugs that act on the liver to increase rates of metabolism are ____
inducers