Vocabulary Flashcards
Those with a narrow therapeutic index, high incidence of adverse effects, or high incidence of allergic reactions.
High Risk Drugs
Those that would be least likely to tolerate adverse effects or loss of efficacy.
ex. The very young, the elderly, brittle diabetics, patients predisposed to arrhythmias or epilepsy.
High Risk Patients
- Immune system mediated response, non-dose related, unpredictable.
- rash, hives, itching.
- Anaphylactic reaction: Bronchoconstriction, swelling of lips, face, throat, tongue, and severe hypotension.
Drug Allergy
adverse effects of a drug that limits its usefulness or acceptance in a patient
Intolerance
caused increased adverse effects or decreased efficacy.
Drug Interaction
harmful or destructive effects of a drug often seen when therapeutic doses are exceeded, the drug is used for a longer period of time than is recommended, or the drug is not properly monitored.
Toxicity
*many use the terms toxicity and adverse effect interchangeably
undesired pharmacological effects of a drug.
usually dose related
Adverse effect
any undesired, unintended response to a drug.
ADR (adverse drug reaction)
- exaggerated drug response
ex. blood pressure medication that unexpectedly bottoms out the patients blood pressure.
refers to the degree to which a drug acts upon one site relative to all possible sites.
Selectivity
*usually, the more selective a drug is, the fewer adverse effects it will cause.
measure of the strength of attraction between a drug and its receptor.
describes the tightness of the bond
Affinity
- a drug with a high affinity to a certain receptor is very likely to elicit that response.
- a drug with a low affinity, is less likely to elicit that response, or may only do so in some patients or when used in very high doses.
A drug that binds with a receptor, blocks the receptor from stimulation, and prevents it from being triggered normally.
Antagonist
A drug that mimics some natural compound by binding with the receptor and stimulating some cellular response.
Agonist
A drug produces an effect by combining with some specific molecular constituent.
Receptor theory
*The function of the receptor or cell is modified to produce a measurable effect.
measure of the amount of drug (dose, mg) required to produce a given degree of effect.
Potency
The ability of a drug to produce a desired therapeutic effect.
Efficacy
Time required for the drug’s plasma concentration to be reduced by one-half.
Specifically refers to the plasma concentration only, while duration of effect refers to the pharmacological action.
Half-Life (t 1/2)
- takes 4-5 half lives for a drug to be considered “cleared”
- most drugs follow “linear kinetics” That is, the half-life is concentration & dose independent.
- t 1/2 does NOT depend on dose.
the length of time a drug can be expected to exhibit its pharmacological effect.
Duration of Action
*usually correlates with the half-life of the drug, but not always.
a general term used to describe the volume of blood which is completely cleared of a drug per unit of time.
Drug clearance
*included the combination of metabolism or excretion by any route.
process by which the drug is eliminated from the body.
Excretion
- some drugs are excreted after metabolism
- some drugs are excreted “unchanged”
> > kidney, bile, intestine, lung, saliva, skin
inactive compound that must be metabolized in order to become active.
> 2 reactions<
Prodrug
Phase 1 reactions: hepatic microsomal enzyme system: Cytochrome p450 (CYP2D6, CYP3A3/4, etc…)
Phase 2 reactions: usually no change with age.
drugs absorbed in the small intestine are first exposed to the liver and may be extensively metabolized before reaching systemic circulation.
First-pass metabolism
*can greatly lower % bioavailability
biotransformation-chemical alteration of the parent compound usually resulting in enhanced excretion, inactivation, or sometimes active metabolites.
Metabolism
Some drugs are bound to plasma proteins, mostly albumin.
Drugs bound to these proteins are pharmacologically inactive while bound.
Protein binding
useful in estimating the loading dose necessary to achieve adequate plasma levels
Vd
volume of distribution
mathematical concept describing the amount of drug in the body in relation to the concentration of drug in the plasma
Volume of Distribution
Vd
movement of drug into the various body fluids and tissues
Distribution
fraction (%) of drug available in the bloodstream after administration as compared to the IV route.
Bioavailability
- IV route is 100% bioavailable
- IM & SC route is also usually 100% bioavailable, although absorption may be delayed.
- The AUC (area under the curve) for each route is calculated & compared.
the impact of the body on drugs
Pharmacokinetics
- Absorption
- Distribution
- Metabolism
- Excretion
the impact of drugs on the body
Pharmacodynamics
The BIG 3 for an Ideal Drug
Effectiveness: one that elicits the response for which it is given.
Safety: one that cannot produce harmful effects, even if administered in very high doses and for a very long time there is NO such thing as a safe drug.
Selectivity: one that elicits only the response for which it is given. A drug that would not produce side effects.
No such thing as a selective drug. All drugs produce side effects.
the use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy.
Therapeutics
the study of drugs in humans
Clinical Pharmacology
the study of drugs and their interactions with living systems
Pharmacology
Any chemical that can affect living processes.
Drug
molecules that have a net electrical charge (+/-)
unable to cross membranes.
Ions
the movement of a drug from its site of administration into the bloodstream
Absorption
- the rate of absorption determines how soon effects will begin.
- The amount of absorption helps determine how intense effects will be.
- Not always desired, as with inhaled or topical steroids or the antibiotic neomycin that is used topically in the GI tract.
