Chapter 3 Vocab Flashcards
(41 cards)
Four Phases of Pharmacokinetic phase.
-absorption
-distribution
-metabolism (biotransformation)
-excretion (elimination)
Pharmacokinetic phase
What the body does to the drug
Absorption-
the movement of medications from the location of administration (gastrointestinal tract, muscle skin, mucous membranes, or subcutaneous tissue} to the bloodstream.
The most common routes are enteral (by mouth through the GI tract) and parenteral (by injection).
Distribution-
The transportation of medication to sites of action by bodily fluids. (Movement of the drug from the circulation to body tissues)
Metabolism (biotransformation)
-The process by which the body chemically changes drugs into a form that can be excreted.
-Changes medications into less active or inactive forms by the action of enzymes. This occurs primarily in the liver, but also takes place in the kidneys, lungs, intestines, and blood.
Excretion-
-the elimination of medications from the body primarily through the kidneys. Elimination also takes place through the liver(bile), lungs, saliva, sweat, intestines, and exocrine glands (such as breast milk)
-Kidney dysfunction can lead to an increase in the duration and intensity of a medication’s response, so it is important to monitor blood urea nitrogen (BUN) and creatinine levels.
addictive effect
When two drugs are administered in combination and the response is increased beyond what either could produce alone, the drug interaction. It is the sum effect of two drugs. can be desirable or undesirable.
Synergistic effect
When two or more drugs are given together, one can have a synergistic effect on the other. In other words, the clinical effect of the two drugs given together is substantially greater than that of either drug alone.
Absorption across the mucosal lining of the small intestines occurs through passive transport 9diffusion and facilitated diffusion), active transport, and pinocytosis.
Passive transport-Does not require energy to move drugs across the cell membrane.
-Has two processes:
diffusion-drugs move across the cell membrane from one area of higher concentration to one of lower concentration.
facilitated diffusion-relies on a carrier protein to move the drug from one area of higher concentration to one of lower concentration.
Active transport-requires a carrier, such as enzyme or protein, to move the drug against a concentration gradient. Energy is required for active absorption.
Pinocytosis-the process by which cells carry a drug across their membranes by engulfing the drug particles in a vesicle.
Bioavailability-
The percentage of the administered drug available for activity.
Medication reconciliation
An accurate list of medication
First pass effect- (First pass metabolism)
After absorption of oral drugs from the GI tract, they pass from the intestinal lumen to the liver via the portal vein. In the liver some drugs are metabolized to an inactive form and are excreted, thus reducing the amount of active drug available to exert a pharmacologic effect.
Free drugs
Drugs that are able to exit blood vessels and reach their site of action, causing a pharmacological response.
Blood-brain barrier (BBB)
Blood vessels in the brain have special endothelial lining where the cells are pressed tightly together (tight junctions). The BBB protects the brain from foreign substances. which includes about 98% of drugs on the market.
Prodrug-
a compound that is metabolized into an active pharmacologic substance.
-designed to improve bioavailability
-instead of administering a drug directly a prodrug might be used instead to to improve pharmacokinetics (absorption, distribution, metabolism, excretion), decrease toxicity, or target a specific site of action.
half-life
The time it takes for the amount of a drug in the body to be reduced by half.
steady state
-A plateau drug level
-occurs when the amount of drug being administered is the same as the amount of drug being eliminated.
loading dose
A large initial dose of medication that is significantly higher than the dose needed to obtain therapeutic effects of the drug while the steady state is reached.
-a loading dose will produce toxic side effects if given in repeated doses.
pharmacodynamics-
the study on the affects of the drugs on the body. (what the drugs do to the body)
Dose-response relationship
The body’s physiologic response to changes in drug concentration at the site of action.
Potency-The amount of drug needed to elicit a specific physiologic response to a drug.
maximum efficacy- The point at which increasing a drug’s dosage no longer increases the desired therapeutic response.
Therapeutic index(TI)-describes the relationship between the therapeutic dose of a drug (ED) and the toxic dose of a drug(TD)
Therapeutic range-(therapeutic window)-a range of doses that produces a therapeutic response without causing significant adverse effect in patients.
Onset-
The time it takes for a drug to reach the minimum effective concentration (MEC) after administration.
Peak
A drug’s peak occurs when a drug reaches its highest concentration in the blood.
Duration of action-
The length of time the drug exerts a therapeutic effect.
Peak drug level-
-The highest plasma concentration of a drug at a specific time, and it indicates the rate of absorption. If the peak is too low, effective concentration os too low.
-If the peak drug level is ordered, a blood sample should be drawn at the appropriate peak time based on the route of medication.
