Chapter 2 Flashcards
Preclinical stage
Early part of drug development.
Identification of promising drugs and their testing on animals occurs in this stage.
Clinical stage
Pharmaceutical companies establish the safety and effectiveness of new products in humans during this stage.
Phase I clinical trials
Establish biological effects, as well as safe dosages and pharmacokinetics in a small number of healthy people.
Phase II clinical trials
New drugs are used to treat in small number of patients and to establish the potential of a drug to improve patient outcomes.
Phase III clinical trials
Compares the new medication to standard therapy in a larger number of patients studied by at sites across the country.
Post-marketing sureveillance
Surveillance during which health professionals are encouraged to report adverse events experienced while on the new drug.
Clinical trial
Stage where several thousand patients receive a new drug.
Post-marketing period
Larger population receives new drug. Additional adverse effects are identified, if they arise.
Pharmacogenomics
Study of how individual variations in drug targets or metabolism affect drug therapy.
Helps identify factors that are responsible for beneficial or adverse effects in individual patients.
Homeostasis
Cell, tissue, or body does not respond to drug, but instead maintains internal environment by adjusting physiological processes.
Pharmacology
Study of substances that produce biological responses.
Graded drug response
Biological effects that can be measured continually up to the maximum resounding capacity of the biological system.
- blood pressure
- heart rate
- diuresis
- bronchodilation
- FEV1
- pain
- coma
Quantal drug response
Drug responses that may or may not occur.
- convulsions
- pregnancy
- rash
- sleep
- death
Drug potency
How much drug is needed to produce a biological response.
Drug efficacy
The maximum effect a drug can produce.
Drug intrinsic activity
The ability of a drug to produce a response once it has occupied specific receptors.
Drug selectivity
A ratio of the dose or concentration producing the undesired effect to the dose or concentration producing the desired effect.
Therapeutic index
Ratio of lethal dose of the drug to the therapeutic dose of the drug.
Therapeutic index for drugs on the market is always greater than 1.
Placebo effect
Pharmacological effect that is not due to the active ingredient.
Structure-activity relationship (SAR)
Correlation of chemical structure with pharmacological activity.
Ion channel receptors
Transmit signals across the cell membrane by increasing the flow of ions and altering the electrical potential or separation of charged ions across the membrane.
Produce responses with rapid onset and short duration.
• muscle movements
Examples:
ACh (nicotinic)
Gamma-aminobutyric (GABA)
Excitatory amino acids (glycine, aspartate, and glutamate)
Receptors coupled to G proteins
Proteins that cross the cell membrane 7 times, creating a pocket in which drugs can interact. Bound drugs may stimulate the receptor to release G protein that can interact with various effector proteins to produce a physiological response.
•Heart beat
Examples:
Alpha
Beta
Gamma
Transmembrane receptors
Receptors that consist of extra cellular hormone-binding domain and intracellular enzyme domains that phosphorylates the amino acid tyrosine.
Examples:
Receptors for insulin
Receptors for epidermal growth factor
Platelet-derived growth factor
Intracellular receptors regulating gene expression
Liquid soluble hormones can pass through the cell membrane and bind to intracellular receptors. The receptor moves to the nucleus, where it controls the transcription of genes by binding to specific DNA sequences.
Example: Corticosteroids Mineralcorticosteroids Sex steroids Vitamin D Thyroid hormones