11 Pharma Flashcards
describe drug schedule I
require a prescription for sale and are provided to the public by the pharmacist following the diagnosis and professional intervention of a practitioner
the sale is controlled in a regulated environment as defined by provincial pharmacy legislation.
describe drug schedule II
while less strictly regulated, do require professional intervention from the pharmacist at the point of sale and possibly referral to a practitioner.
while a prescription is not required, the drugs are available only from the pharmacist and must be retained within an area of the pharmacy where there is no public access and no opportunity for patient self-selection.
describe drug schedule III
schedule III drugs may present risks to certain populations in self-selection
although available without a prescription, these drugs are to be sold from the self-selection area of the pharmacy which is operated under the direct supervision of the pharmacist, subject to any local professional discretionary requirements which may increase the degree of control.
such an environment is accessible to the patient and clearly identified as the “professional services area” of the pharmacy.
the pharmacist is available, accessible and approachable to assist the patient in making an appropriate self-medication selection.
describe drug schedule “unscheduled drugs”
can be sold without professional supervision
adequate information is available for the patient to make a safe and effective choice and labeling is deemed sufficient to ensure the appropriate use of the drug.
these drugs are not included in Schedules I, II or III and may be sold from any retail outlet.
define pharmacodynamics
the study of the biochemical and physiologic effects of drugs and their mechanisms of action on the body or on microorganisms and other parasites within or on the bod
define drug action and drug effects
drug action: initial consequence of a drug-receptor interaction
— not all drugs exert their actions via receptor-mediated interactions (can be physical mechanism)
drug effect: subsequent effects
define pharmocokinetics
movement of drugs thru the body
what are the steps of pharmacokinetics
liberation
— release of a drug from pharmaceutical formulation
absorption
— substance entering the blood circulation
distribution
— dispersion of substance thru out the fluids and tissues
metabolism
— recognition by the organism that a foreign substance is present and the irreversible transformation of parent compounds into daughter metabolites
excretion
— removal of the substance from the body
— in some cases, drug irreversibly accumulates in body tissue
what is an agonist?
drug that binds to receptors and (thereby) alters/stabilizes the proportion of receptors in the active conformation, resulting in a biologic response
a full agonist results in a maximal response by occupying all or a fraction of receptors
a partial agonist results in less than a maximal response even when the drug occupies all of the receptors
differentiate between the types of antagonism
chemical antagonism
—- chemical interactions between a drug and either a chemical or another drug leading to a reduced or nil response
physiologic antagonism
—- when 2 drugs acting on different receptors and pathways exert opposing actions on the same physiologic system
pharmacokinetic antagonism
—- result of one drug supressing the effect of a second drug by reducing its absorption, altering its distribution, or increasing its rate of elimination
pharmacologic antagonism
—- when the antagonist inhibits the effect of a full or partial agonist by acting on the same pathway by not necessarily on the same receptor
what are the 3 types of pharmacologic antagonists?
reversible competitive antagonist
—- results in inhibition that can be overcome by increasing the concentration of agonist
irreversible competitive antagonist
—- also involves competition between agonist and antagonist for same receptor, but stronger binding forces prevents the effect of the antagonist from being fully reversed even at high agonist concentration
noncompetitive antagonist
—- inhibits agonist activity by blocking one of the sequential reactions between receptor activation and the pharmacologic response
how do scientists develop drugs? (what do they consider)
scientists select drug targets in the form of large biomolecules (such as proteins) or cancer cells, then search for molecules that will disrupt the protein or kill the malignant cell.
how was medicine administered historically?
historically, medicines were administered in the form of herbal concoctions.
as science advanced, chemists were able to extract the active ingredients from natural
sources to make more potent medicines.
for example, aspirin (acetylsalicylic acid) was discovered from the willow tree.
what is the first step in modern drug discovery? what comes after?
high-throughput screening
where thousands of molecules are tested at once for their efficacy against a certain drug target
an effective molecule identified this way is then elaborated into a potential drug through further screening with variants of the first molecule
if a more potent drug is found, the molecule is tested in cells and animals to mimic the drug’s behavior in humans.
if the drug proves to be effective in laboratory studies, the next step is a clinical trial. - then market!
describe acetaminophen
tylenol
first made in the 1800s
one of the most widely used over-the-counter drugs
exact mechanisms of action is unclear
—- grouped with NSAIDs because it is a COX inhibitor
—- has analgesic and antipyretic properties but lacks anti-inflammatory properties
