NR565 Week 1 Study Outline
Chapter 2: Review of Basic Principles of Pharmacology
How Drugs are Developed
• Drugs are developed by pharmaceutical companies to help patients and to make money
• The early part of the drug development process is called the preclinical stage
• Pharmaceutical companies will identify a drug target, starting sometimes with ingredients
isolated from a plant (or organism in the case of antibiotics) with desirable medicinal
properties, sometimes with a molecular target identified in the body to produce the desired
response, and sometimes with a disease in need of treatment.
• Many drugs are examined as pharmaceutical companies seek the elusive perfect drug with
just the right combination of properties. Preclinical studies are performed on cells, isolated
tissues and organs, and in laboratory animals to identify promising compounds
• Drugs approved by the Food and Drug Administration (FDA) must be both safe and effective
and are screened by pharmacologists specializing in various aspects of drug activity.
• Ideally, drugs will produce their desired effects at dosages well below those needed to produce
toxicity.
• During the clinical stage of new drug development, pharmaceutical companies must establish
the safety and effectiveness of new products in humans.
• Phase I clinical trials typically establish biological effects as well as safe dosages and
pharmacokinetics in a small number of healthy patients.
o During phase II clinical trials, new drugs are used to treat disease in a small number of
patients and to establish the n potential of the drug to improve patient outcomes.
• If the drug still looks promising, phase III clinical trials will compare the new medication to
standard therapy in a larger number of patients studied by at sites across the country.
• New drugs must be at least as good as, and it is hoped better than, other available therapies.
Throughout the process, pharmaceutical companies work with the FDA.
• After being approved by the FDA, drugs are continuously monitored through post-marketing
surveillance, in which health professionals are encouraged to report adverse events, which are
studied by both pharmaceutical companies and the FDA.
Drug Responses
• Homeostasis is the tendency of a cell, tissue, or the body not to respond to drugs but instead
to maintain the internal environment by adjusting physiological processes.
• Before a medication can produce a response, it often must overcome homeostatic
mechanisms.
• Drug effects depend on the amount of drug that is administered.
o If the dose is below that needed to produce a measurable biological effect, then no
response is observed; any effects of the drug are not sufficient to overcome
homeostatic capabilities.
o If an adequate dose is administered, there will be a measurable biological response.
With an even higher dose, we may see a greater response.
• At some point, however, we will be unwilling to increase the dosage further, either because we
have already achieved a desired or maximum response or because we are concerned about
producing additional responses that might harm the patient.
• Because pharmacology is the study of substances that produce biological responses,
measurement of what happens when we administer medications is important.
• Two types - these responses differ in how they are measured and dictate dosing decisions to
achieve the desired effect.
Chapter 2: Review of Basic Principles of Pharmacology
How Drugs are Developed
• Drugs are developed by pharmaceutical companies to help patients and to make money
• The early part of the drug development process is called the preclinical stage
• Pharmaceutical companies will identify a drug target, starting sometimes with ingredients
isolated from a plant (or organism in the case of antibiotics) with desirable medicinal
properties, sometimes with a molecular target identified in the body to produce the desired
response, and sometimes with a disease in need of treatment.
• Many drugs are examined as pharmaceutical companies seek the elusive perfect drug with
just the right combination of properties. Preclinical studies are performed on cells, isolated
tissues and organs, and in laboratory animals to identify promising compounds
• Drugs approved by the Food and Drug Administration (FDA) must be both safe and effective
and are screened by pharmacologists specializing in various aspects of drug activity.
• Ideally, drugs will produce their desired effects at dosages well below those needed to produce
toxicity.
• During the clinical stage of new drug development, pharmaceutical companies must establish
the safety and effectiveness of new products in humans.
• Phase I clinical trials typically establish biological effects as well as safe dosages and
pharmacokinetics in a small number of healthy patients.
o During phase II clinical trials, new drugs are used to treat disease in a small number of
patients and to establish the n potential of the drug to improve patient outcomes.
• If the drug still looks promising, phase III clinical trials will compare the new medication to
standard therapy in a larger number of patients studied by at sites across the country.
• New drugs must be at least as good as, and it is hoped better than, other available therapies.
Throughout the process, pharmaceutical companies work with the FDA.
• After being approved by the FDA, drugs are continuously monitored through post-marketing
surveillance, in which health professionals are encouraged to report adverse events, which are
studied by both pharmaceutical companies and the FDA.
Drug Responses
• Homeostasis is the tendency of a cell, tissue, or the body not to respond to drugs but instead
to maintain the internal environment by adjusting physiological processes.
• Before a medication can produce a response, it often must overcome homeostatic
mechanisms.
• Drug effects depend on the amount of drug that is administered.
o If the dose is below that needed to produce a measurable biological effect, then no
response is observed; any effects of the drug are not sufficient to overcome
homeostatic capabilities.
o If an adequate dose is administered, there will be a measurable biological response.
With an even higher dose, we may see a greater response.
• At some point, however, we will be unwilling to increase the dosage further, either because we
have already achieved a desired or maximum response or because we are concerned about
producing additional responses that might harm the patient.
• Because pharmacology is the study of substances that produce biological responses,
measurement of what happens when we administer medications is important.
• Two types - these responses differ in how they are measured and dictate dosing decisions to
achieve the desired effect.
