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Dose-response curve - a graph comparing the size of response to the amount of drug.
Double-blind procedure - an experiment in which neither the researcher nor the patient
knows whether the drug or a placebo is being used.
Drug absorption - the passage of a drug from the site of administration to the circulatory
system.
Drug disposition tolerance - tolerance caused by more rapid elimination of the drug.
Drug distribution - the movement of drugs to and from the blood and various tissues of
the body (for example, fat, muscle, and brain tissue).
Drug excretion - the removal of drugs from the body.
Drug metabolism - the process by which the body breaks down drugs.
ED50 - the effective dose for half of the animals tested.
Efficacy - a drug's ability to produce a desired behavioural effect.
Endorphin - opiate-like chemical that occurs naturally in the brain of humans and other
animals
Enzymes - large molecule that assists in either the synthesis or metabolism of another
molecule.
Generic name - a name that specifies a particular chemical but not a particular brand.
Half life - the time it takes for half of the drug to lose its pharmacological or physiological
effects and to be eliminated from the body.
Homeostasis - maintenance of an environment of body functions within a certain range
(e.g., temperature, blood pressure).
Intramuscular - injection into a muscle.
Intravenous (IV) - injection directly into a vein.
LD50 - the lethal dose for half of the animals tested.
Lipid solubility - the tendency of a chemical to dissolve in fat, as opposed to in water.
, Lipophilic - the extent to which chemicals can be dissolved in oils and fats.
Metabolite - a product of enzyme action on a drug.
Metabolize - to break down or inactivate a neurotransmitter (or a drug) through
enzymatic action.
Neurotransmitters - chemical messengers released from neurons and having brief, local
effects.
Parasympathetic - the branch of the autonomic system that stimulates digestion, slows
the heart, and has other effects associated with a relaxed physiological state.
Peripheral Nervous System - a division of the nervous system containing all the nerves
that lie outside the brain and spinal cord.
Pharmacodynamic tolerance - tolerance caused by altered nervous system sensitivity.
Placebo - an inactive chemical or substance.
Potency - measured by the amount of drug (dose) required to produce an effect.
Prodrugs - drugs that are inactive until acted on by enzymes in the body.
Receptors - recognition proteins that respond to specific chemical signals.
Safety margin - the dosage difference between an acceptable level of effectiveness and
the lowest toxic dose.
Semipermeable - allowing some, but not all, chemicals to pass.
Side effect - the unintended effects that accompany therapeutic effects.
Subcutaneous - injection under the skin.
Sympathetic - the branch of the autonomic system involved in flight or fight reactions.
Therapeutic index (TI) - the ratio of LD50 to ED50.
Time Course - the timing of the onset, duration, and termination of a drug's effect.
Topical administration - application of a drug directly to the area where it is needed.
Withdrawal syndrome - symptoms (e.g., muscle aches, anxiety attacks, sweating,
nausea, convulsion, death) resulting from weaning of substance dependence.