Lecture 1 Part 1 Flashcards
define pharmacology
the science that deals with the action and use of drugs.
the study of substances that interact with living systems through chemical processes, especially through binding to regulatory molecules or inhibiting normal body processes
pharmacodynamics + pharmacokinetics
learning pharmacology is among the most important steps to become what?
a physician, pharmacist, or biomedical researcher
rather than __________, modern therapeutics requires an understanding of what?
rather than simply ordering a med to treat a specific symptom or disease, modern therapeutics requires an understanding of the underlying MOA (MECHANISM OF ACTION) of a pharmacological agent
-and how it influences and is influences by the disease. also its capacity for causing harmful/beneficial clinical effects
pharmacology is uniquely positioned among the ___ and ___ sciences
biomedical and pharmaceutical
pharmacology depends on and contributes to what 5 sciences
genetics
biochemistry
cell biology
organ physiology
clinical medicine
the development of ______________ pharmacology helps us to understand the ____ from ______ to _____ level
biochemical and molecular pharmacology
the mechanism of action (MOA) from system, to organ, to molecular level
as mentioned, pharmacology is the study of “substances” that interact with living systems through chemical processes
what are these substances?
-chemicals administered to achieve a beneficial therapeutic effect on some process within the patient
-chemicals that have toxic effects on regulatory processes in PARASITES that have infected the patient
what kind of pharmacology do physicians study?
medical pharmacology
the science of substances used to prevent, diagnose, and treat diseases
what is the “basic principles in therapeutics”
clinical pharmacology
explain the clinical pharmacology (the basic principles in therapeutics) is designed to illustrate
a consistent approach to qualitative and quantitative decision making in therapeutics
(used when drug in clinical trial)
true or false
toxicology is a branch of pharmacology
true
define toxicology
the branch of pharmacology that deals with the UNDESIRABLE effects of chemicals on living systems (from individual cells to complex ecosystems)
true or false
toxicology does not study chemicals that are intentionally toxic
true
the study of the biochemical and physiologic effects of drugs
pharmacodynamics
define pharmacokinetics
the study of ADME or the disposition of drugs in the body
define pharmacotherapeutics
the use of drugs to prevent and treat diseases
what people knew the beneficial or toxic effects of many plant and animal materials?
prehistoric people
early written records from where list many different types of remedies?
name them
india and china
some were beneficial and some were harmful
beneficial - rhubarb used as cathartics (purgative/laxative)
harmful - arsenate used for cancer treatment in china
in the last 2500 years preceding the modern scientific approach, what has been going on with medicine?
sporadic attempts were made to introduce rational thoughts into medicine BUT the predominant schools of thought did not rely on experimentation and observation but rather UNTESTED NOTIONS
as mentioned, in the last 2500 years, preceding the modern scientific approach, the predominant schools of thought relied on UNTESTED NOTIONS rather than experimentation and observation
give an example of one of these untested notions.
what was the result of this lack of experimental medicine?
disease was caused by excess blood/excess bile
many treatments were thus unhelpful or even worse than no treatment at all
around the end of what century did medicine begin to rely on observation and experimentation?
these principles were first established by what science?
end of 17th century
principles first established by the physical sciences
__________________ began to apply the methods of observation and experimentation to study the effects of traditional drugs used in their respective practices
physicians in great britain and elsewhere in europe
(~ end of 17th century)
physicians in great britain (and elsewhere in europe) using the methods of experimentation/observation to study the effects of drugs began WHAT
materia medica —- the science of drug preparation and the medical use of drugs
what was the precursor of modern pharmacology
materia medica
materia medica is what
the science of drug preparation and the medical use of drugs.
the precursor to modern pharmacology
materia medica was the precursor to modern pharmacology.
however, the understanding of what was prevented?
why?
understanding the mechanism of action was prevented
this is because the absence of methods to purify active agents from the crude materials AND EVEN MORE by the lack of methods for testing hypotheses about the nature of drug actions
what happened in the late 18th and early 19th centuries
Francois Magendie (french) and Claude Bernard developed methods of experimental animal physiology and pharmacology (START OF ANIMAL EXPERIMENTS)
Advances in ____ and further development of ____ in the 18th, 19th, and early 20th century laid the groundwork for what?
chemistry, physiology
for how drugs work at the organ and tissue levels
paradoxically, real advances in basic pharmacology in the 19th century were accompanied by what
an outburst of nonscientific patent medicines
it was not until the concepts of _______ were introduced into medicine that it became possible to ACCURATELY EVALUATE THERAPEUTIC CLAIMS
rational therapeutics, especially those of the controlled clinical trial
about 50 years ago, there was a major expansion of ____ efforts in all areas in biology.
what has this enabled?
research efforts
thus these new concepts and techniques enabled discoveries concerning the MOA of drugs, physiological substrates, and receptors
true or false
the molecular mechanisms of action of many drugs have now been identified and many receptors have been isolated, structurally characterized, and cloned
true
the extension of scientific principles in everyday therapeutics is still going on.
however…
the public is still exposed to amounts of inaccurate, incomplete, or unscientific info regarding the pharmacologic effect of chemicals
this has resulted in growth of the ALTERNATIVE HEALTHCARE industry – faddish use of potentially harmful remedies
what has led to the rejection of medical science by a segment of the public and a distrust of healthcare professionals?
lack of understanding of basic scientific principles in biology and statistics and lack of critical thinking about public health issues
when and how did the significance of the kidney secretory system become clear?
during WW2 when penicillin was introduced
it was in short supply and thus rapid renal excretion was a problem.
discovery of probenicid (benzoic acid derivative) in 1951 – competed with the tubular secretion of penicillin and thus prevented its rapid loss from the body and prolonged antibiotic activity
true or false
when probenecid is taken with penicillin, the reabsorption of penicillin is enhanced and it thus stays in the body longer
true
as the years have gone on, is probenecid still used as a penicillin sparing drug?
no
large scale production procedures and new semi-synthetic congeners became available.
short supply of penicillin no longer an issue
after its use in 1951, when did probenecid reappear on the scene and why
in 1988
used by spanish cyclist at Tour de France. Pedro Delgado had probenecid in his urine.
reduces the transport of metabolites of forbidden anabolic steroids into the urine
he passed the doping test bc probenecid was not a masking agent on the doping list
NAME THE 2 GENERAL PRINCIPLES THAT STUDENTS SHOULD ALWAYS REMEMBER
-all substances can be toxic under certain circumstances
-all therapies that are promoted as “health enhancing” should meet the SAME STANDARDS OF EVIDENCE FOR EFFICACY AND SAFETY.
-there should be no artifical separation between scientific medicine and “alternative” or “complementary” medicine
true or false
there should be no artificial separation between scientific medicine and alternative or complementary medicine
true
all therapies that are promoted as health enhancing should….
meet the same standards or evidence for safety and efficacy
in a general sense, any substance that __________ is a drug
any substance that brings about a change in biologic function through its chemical actions
true or false
in all cases, a drug molecule interacts with a specific molecules in the biologic system that plays a regulatory role (receptor)
false
majority of cases but not all
receptors play a _____- role
regulatory
in a very small number of cases, ___________ may interact DIRECTLY WITH OTHER DRUGS (and not a receptor)
drugs known as chemical antagonists
true or false
drugs cannot be synthesized within the body
false – they can and they are called hormones
true or false
drugs may be synthesized within the body or be chemicals not made by the body
true
if synthesized in the body = hormones
if chemicals NOT made by the body = xenobiotics
where does the word xenobiotics come from
from the greek word for “stranger”
define a poison
a substance that, through its chemical action, usually kills, injures, or impairs an organism
define toxins
poisons of biological origin synthesized by plants or animals
OR inorganic poisons (lead, cyanide, arsenic)
true or false
drugs can be poisons
true
in order to chemically interact with its receptor, a drug must have what 4 appropriate things?
size
electrical charge
shape
atomic composition
“lock and key”
true or false
a drug is usually given at a location close to its intended site of action
FALSE - distant from
give an example of how a drug is often administered at a location distant from its intended site of action
a pill given orally to relieve a headache
as mentioned, a drug is often administered at a location distant from its intended site of action.
what can you conclude from this?
a drug must have the necessary properties to be TRANSPORTED from its site of administration to its usually distant site of action
how can you ensure that the actions of the drug will only remain for the appropriate duration?
the drug should be inactivated or excreted from the body at a reasonable rate
true or false
every cell/tissue has the capacity for metabolism, but the liver is the main
true
when a drug is absorbed, where does it go?
into the plasma
when a drug is in the plasma (after being absorbed), where can it go?
it can reversibly leave the plasma (bloodstream) and be DISTRIBUTED into intracellular fluids
OR can bypass everything and go straight to elimination
when the drug is reversibly distributing between the tissues and plasma, some of the drug in the tissues is doing what?
getting metabolized
the metabolites in the tissues then get eliminated in the urine/feces/bile
what is the “input” step of pharmacokinetics?
what about output?
input = absorption
output = elimination
name 3 places in which the drug and/or metabolites can be eliminated
urine
feces
bile
at room temp, drugs can be what state(s) of matter?
solid liquid and gas
solid = aspirin
gas = nitrous oxide
liquid = nicotine, ethanol
what best influences the route of administration of drugs? explain
their physical nature (state of matter) at room temp
ex - some liquid drugs are easily vaporized and can be inhaled in gas form
ie: HALOTHANE
TRUE OR FALSE
many drugs are weak acids or bases
true
many drugs are weak acids or bases
how does this have important implications
because the pH differences in various compartments of the body may alter the degree of ionization of these weak acid/base drugs
what does p.r stand for
rectal (route of administration)
what does s.c. stand for
subcutaneous (route of administration)
true or false
transdermal is a common route of administration
true
what does i.m. stand for
intramuscular (route of administration
explain the MW of drugs
can vary from very small to very large
lithium ion MW = 7
alteplase MW = 59,050
MOST drugs have MW 100-1000 – to achieve selective binding
in order to have a good “fit” to only one type of receptor and prevent binding to other receptors, a drug molecule must be………
sufficiently unique in shape, charge, etc
how is the upper limit of MW determined?
primarily by the requirement that drugs have to be able to move within the body (from site of administration to site of action
very large drugs are usually ____
proteins
the upper limit of MW is primarily determined by the requirement for drugs to be able to move within the body from the site of administration to the site of action.
THEREFORE, how should very large drugs (usually proteins) be administered?
directly into the compartment where they have their effect, since they may have distribution issues
explain what alteplase is and how it is administered
a clot dissolving, very large MW enzyme (59,050)
administered directly into the vascular compartment (where it has its effect) through IV infusion
