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
how is acetaminophen synthesized?
IN GENERAL
— distillation of crude oil to produce naphtha
— catalytic reforming: naphtha to benzene
— benzene to acetaminophen
DIFFERENT ROUTES FOR THE INDUSTRIAL PRODUCTION OF ACETAMINOPHEN
— route 1: nitration of chlorobenzene
— route 2: nitration of phenol
— route 3: reduction of nitrobenzene
— route 4: acetamidation of hydroquinone
define biologics
a product that is produced from living organisms or that contains components of living organisms.
can be derived from humans, animals, or microorganisms using biotechnology
change the manner of operation of natural biologic intracellular and cellular actions
may contain proteins that control the action of other
proteins and cellular processes, genes that control
production of vital proteins, modified human hormones,
or cells that produce substances that suppress or activate components of the immune system
gene-based and cellular biologics, for example, often are at the forefront of biomedical research and may be used to treat a variety of medical conditions for which no other treatments are available
are often heat-sensitive, membrane-impermeable, subject to enzymatic degradation, and susceptible to microbial contamination
how has genetic engineering impacted the development of biologics?
advent of genetic engineering during the late 1970s and early 1980s opened up new avenues for biologics production and development.
ability to modify genetic sequences meant that researchers could modify existing agents to improve their stability, safety, and/or
efficacy.
these alterations could also be used to change agent targeting specificity, giving certain agent types, such as antibodies, a significantly greater range of applications.
describe dosage of biologics
biologics are often dosed based on factors such as body weight or surface area, due to the impact of body size on PK, PD, and clinical response, and certain modeling and simulation approaches can be used to determine dosing regimen and exposure-response relationships
single- and multiple-dose PK and toxicokinetic studies are designed to assess absorption, disposition, exposure, and clearance and to explore dose-response relationships.
describe the side effects of biologics
like all drugs, biologic therapies have the potential to cause side effects. Since biologics can suppress the immune system, there is increased risk of upper respiratory infections, urinary-tract infections, skin infections, pneumonia, and other infections.
immunogenicity can also lead to a loss of therapeutic efficacy, the formation of immune complexes, or cross-reactions with endogenous substances.
immunogenicity testing is often needed in screening and mechanistic studies for biologics.
what are biosimilars?
a similar role for biologics as generics do for small molecule drugs, could be associated with lower spending
one reason why biosimilars have not been successful in the US even after they have been marketed has been the message from drug companies, medical societies, and patient groups that it is potentially dangerous to switch patients from a reference biologic to a biosimilar
what is mRNA?
messenger RNA (abbreviated mRNA) is a type of single-stranded RNA involved in protein synthesis
made from a DNA template during the process of transcription
describe mRNA as a drug/vaccine
was seen as too unstable and
expensive to be used as a drug or a vaccine.
dozens of academic labs and companies worked on the idea, struggling with finding
the right formula of fats and nucleic acids — the building blocks of mRNA vaccines.
biggest challenge was that mRNA would be taken up by the body and quickly degraded before it could “deliver” its message and be read into proteins in the cells.
—- solution to this problem came from advances in
nanotechnology: the development of fatty droplets (lipid nanoparticles) that wrapped the mRNA like a bubble, which allowed entry into the cells.
as far back as 1978, scientists had used fatty membrane structures called liposomes
to transport mRNA into mouse and human cells to induce protein expression.
what is the general drug approval process?
the drug manufacturer must submit scientific evidence of the product’s safety, efficacy, and quality to Health Canada for review and approval
the federal review process can take between 1 - 2 years, depending on the nature of the product
once Health Canada approves the product for sale in Canada, a Notice of Compliance (NOC) and a Drug Identification Number (DIN) are issued for the product
approval of a product for marketing by Health Canada does not automatically mean that it will be publicly funded
drug manufacturer’s responsibility to seek public drug program funding by filing a complete submission according to the ministry’s established evidence-based drug funding review process
a NOC signifies compliance with the Food and Drug Regulations
as a non-cancer drug, what is the review process?
to be considered for funding under most public drug plans, a manufacturer must file a submission to the national CDR process
the CDR is a single process for undertaking reviews and providing common listing recommendations for new drugs (except for new cancer drugs), based on rigorous clinical and pharmacoeconomic analyses and patient input, to participating federal, provincial and territorial drug benefit plans in Canada
all jurisdictions participate excluding Quebec
the CDR is administered by the Canadian Agency for Drugs and Technologies in Health (CADTH)
receives expert advice from the Canadian Drug Expert Committee (CDEC) which makes recommendations to the participating jurisdictions
as a cancer drug, what is the review process? – pan-Canadian Oncology Drug Review (pCODR)
evidence-based cancer drug review process
brings consistency and clarity to the assessment of cancer drugs by reviewing clinical evidence, cost-effectiveness, and patient perspectives, and using this information to make recommendations to Canada’s provinces and territories (except Quebec) in guiding their drug funding decisions
administered by the Canadian Agency for Drugs and Technologies in Health (CADTH)
receives expert advice from the pCODR Expert Review Committee (pERC), which makes recommendations to the participating jurisdictions regarding coverage
what is ontario’s drug review process?
drugs are considered for funding in Ontario based on a thorough assessment of the scientific clinical evidence and patient perspective, as well as the impact on health services as compared to existing treatments in Ontario
new drug products, including requests for different indications of existing drug products, may be considered for funding in Ontario if the manufacturer makes a complete submission to the ministry
new drugs and new indications that are approved by Health Canada are first reviewed under the national Common Drug Review (CDR) process, with overall assessments of the clinical, pharmacoeconomic and patient evidence by the Canadian Drug Expert Committee (CDEC)
CDEC then issues a recommendation to participating provincial and territorial drug plans, recommending whether or not, and according to what criteria and/or conditions the drug should be considered for funding by public drug plans
following the release of the final CDEC recommendation, it is up to each province to decide whether to fund the drug product as a benefit under its own provincial drug plan(s). the pan-Canadian Oncology Drug Review (pCODR) and the pCODR Expert Review Committee (pERC) perform the same function for cancer drugs
April 1, 2016, Ontario streamlined the drug evaluation process for drugs already assessed by the national CDR or pCODR processes to align and reduce duplication in the evaluation process
