Intro Flashcards
What is pharmacology?
the study of substances that alter bodily functions when introduced into an organism
What did people do medically in ancient times?
pain and diseases were treated with different plant and animal extracts
When did the science of drug preparation begin?
17th century
When was the concept of controlled clinical trial introduced?
~60 years ago
What is the present focus of drug research?
drug receptors (substrate)
What is the future of drug research?
study of genetic makeup and individual response to specific drugs aka pharmacogenomics
T/F all substances can be toxic under certain circumstances
true
T/F all medications have side-effects
true, but not every patient will experience every side effect
What ratio is evaluated when considering a new drug for a patient?
the risk/benefit ratio
T/F all OTC products are regulated to the highest standard
false
Define a drug
any substance that alters body function when introduced into a living organism
What does a drug effect?
a specific target molecule (receptor)
What does a drug effect depend on?
size, electrical charge, shape, and atomic composition
What is pharmacodynamics?
the actions of the drug on the body aka effects at the receptor and the results
What is pharmacokinetics?
the actions of the body on a drug aka absorption, metabolism and excretion how the drug gets into and out of the body
What is an agonist?
binds to and activates a receptor
What are the two types of agonists?
full and partial
What is an antagonist?
prevents other molecules from binding to a receptor
What are the two types of antagonist?
reversible or irreversible
What is the principle behind administration/absorption?
the intended site of drug action must be reachable by the drug
What is the principle behind metabolism?
a drug may reach its intended target as an active molecule or it might require conversion prior to being active (prodrug)
What is the principle behind distribution?
most often a drug is administered into one body compartment and must move to the intended site of action
What is the principle behind elimination?
a drug must be eliminated after it has an effect
What are some examples of drug classifications?
natural preparations, pure compounds, semi-synthetic compound, synthetic compounds, and biological drugs
What are some examples of therapeutic effect classifications?
anti-hypertensives, anti-convulsants, anti-bacterial, anti-fungal, anti-psychotic, anti-arrhythmic
What are drug classification examples in society?
prescription, OTC, dietary, herbal, recreational, commercial, agricultural
What three names do drugs have?
chemical, generic, and brand
T/F a drug has more than one generic name
false
How long do patents on a new drug last?
20 years
T/F exclusive right to see a drug lasts as long as the drug patent
false
How long does trade name last?
50 years
How long does it take from patenting to marketing?
8-10 years
What are the 5 steps in drug development?
discovery, study of biological interactions, study of safety, marketing, post-marketing
What does the study of biological interactions lead to?
increased efficacy, potency, and selectivity
What is phase 4?
post-marketing studies, ongoing
T/F the majority of marketed drugs return their R and D investments
false only 2/10
What is the global market for pharmaceuticals?
over $950 billion
What percent of health care expenses in the US is prescription drugs?
10-12%
What are four ways new drugs are developed?
identification of a new drug target, design of a new molecule based on understanding of receptor structure, screening for biological activity of natural products, and chemical modification of a known active molecule
T/F the type and number of of initial screening tests depends on the pharmacologic and therapeutic goal
true
What body systems are studied first for drug effects?
cardiovascular and renal
Which four results of drug screenings result in modifications to the drug compound?
poor bioavailability, interactions with liver enzymes, potential for abuse, potential for drug interactions
What is a lead compound?
the result of all screening procedures
What can receive a “use patent”?
a previously known chemical entity discovered to have a new therapeutic use
What are the two goal outcomes of toxicity testing?
defining the limiting toxicities and the therapeutic index
What is acute toxicity?
determines the no-effect dose and the maximum tolerated dose
What is subacute toxicity?
determines biochemical and physiologic effect of long-term dose (weeks to months)
What is chronic toxicity?
used when drug is expected to be needed in humans for prolonged periods of time
What are additional toxicity considerations?
effect on reproductive performance, carcinogenic potential, mutagenic potential
What are limitations of preclinical testing?
time consuming and expensive, need large numbers of animals, animals vs humans needs to be considered, rare adverse effects are not likely to be identified
Who oversees human testing?
FDA
T/F a drug can be completely absent of risk
false
What are confounding factors in clinical trials>
variable nature of most diseases, presence of other diseases or risk factors, subject and observer bias (placebo effect)
What needs to be filed with the FDA for drug clinical trials?
notice of claimed investigational exemption for a new drug
What info does the FDA need to know about a drug?
composition and source, chemical and manufacturing info, data from animal studies, proposed plans for clinical trials, names and credentials of physicians conducting trials, key data relevant to study of the drug in humans
What does phase 1 entail?
effects of the drug as a function of dosage on a small number of healthy volunteers, determine the probable limits of the safe clinical dosing range (sometimes study absorption, half-life, and metabolism)
What is the exception for using healthy volunteers in phase 1 of clinical trials?
can use individuals with the disease IF the drug is expected to have significant toxicity ex: AIDS, cancer
What does phase 2 entail?
drug is studied in small number of patients with the target disease to determine efficacy and determine doses
What phase do most drugs fail?
phase 2, only 25% of new drugs get past phase 2
What does phase 3 entail?
drug is evaluated in larger numbers (thousands) of patients with the target disease in a clinical setting
What needs to be accomplished in phase 3?
establish and confirm safety and efficacy, minimize errors caused by placebo effects and disease variations
What does marketing approval require?
submission of a new drug application NDA with full reports of all preclinical and clinical trials, can take months to gain approval
What does phase 4 entail?
monitoring the safety of the new drug under actual conditions of use in large numbers of patients, no fixed durations
What is the responsibility of a physician using a medication in phase 4?
need to report adverse effects
What is the average effective patent life for major pharmaceuticals?
11 years
What happens when a patent expires?
any company can produce the drug without paying license fees after filing an abbreviated NDA
What percent of prescriptions in the US are for generics?
67%
What are examples of conflicts of interest in drug development?
manufacturers paid physicians to prescribe, sponsoring of poorly designed clinical studies, sponsoring CE events for physicians, distributing samples
