1 - Cells, Diffusion, Basics Flashcards
Defines the dose of drug that is lethal to 1% of population compared with dose therapeutically effective in 99% (LD1/ED99).
Certain Safety Index
The difference of content between one side of the cell membrane and the other; the larger the difference, the faster the diffusion.
Concentration Gradient
These describe the extent of biological or behavioural effect produced by a given drug dose on a population. Plotted on a semi-log scale, it has an S-shape. At low doses, drug-induced effect is slight because very few receptors are occupied. The ____ ____ is the smallest dose that produces a measurable effect. As the dose of drug increases more receptors activate and a greater biological response occurs.
___ __ is the dose that produces half of maximal effect (the more potent drug is the one for which it is lower) and ___ ___ occurs at a dose where we assume receptors are maximally occupied.
These graphs show that with increasing doses, the effect increases steadily until the maximum effect is reached.
Dose–Response Curve | Threshold Dose | ED50 | ED100
The reduction in a cellular response to a molecule due to a decrease in number of receptors on cell surface. The process of reduces / suppresses a response to a stimulus.
Down-Regulation
Refers to specific molecular changes produced by a drug when it binds to a particular target site or receptor.
Drug Action
All drugs have multiple effects and can be sorted/identified in any of several ways depending on the trait of interest.
Drug Category

Molecular changes from drug action lead to more widespread alterations in physiological or psychological functions.
Drug Effects
Effects of drug are determined by 2 primary factors and are qualified by other issues (2)
- How muach drug reaches its target sites, where it has biological action, and
- how quickly the drug reaches those sites.
qualified by
- Nonspecific characteristics of individuals/environments;
- Frequency/history of prior use — time gap; same dose may overdose/kill
Inflammation of heart lining
Endocarditis
A network of tubules within the liver cell cytoplasm. Liver enzymes primarily responsible for metabolizing psychoactive drugs are located here.
Endoplasmic Reticulum
Drugs pass through the liver and become subject to metabolism/biotransformation
First Pass Effect
Family of proteins that act as molecular switches inside cells. Involved in transmitting signals from variety of stimuli outside cell to interior.
GNBP
Guanine Nucleotide-Binding Proteins. G proteins.
These bind to a receptor and initiate a biological action that is the opposite of what would be produced by an agonist.
Inverse Agonists
Any molecule that binds to a receptor with some selectivity.
Ligand
Concerned with drug-induced changes in the functioning of cells in the nervous system.
Neuropharmacology
Its goal is to identify chemical substances acting on the nervous system which alter behaviour that is disturbed due to injury, disease, or environmental factors. Also interested in using chemical agents as probes to gain understanding of neurobiology of behaviour.
Neuropsychopharmacology
Drugs that reduce effects of agonists in ways other than competing for receptors. May impair agonist action by binding to portion of receptor other than agonist-binding site, by disturbing cell membrane supporting the receptor, or by interfering with intracellular processes that were initiated by the agonist–receptor association.
ex: the analgesic dose–response curve of morphine is distorted and the same maximum effect is not likely to be reached.
Non-Competitive Antagonists
Demonstrate efficacy that is less than that of a full agonist but more than that of an antagonist at a given receptor.
Partial Agonist
A substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space.
Passive diffusion
How our cells breath; CO2 leaks out and oxygen goes in same way.
The study of physiological and biochemical interactions of drug molecules with target tissue responsible for the ultimate effects of a drug. Drugs have biological effects because they interact with receptors on target tissues.
Pharmacodynamics
Study of genetic basis for variability in drug response in individuals. Goals are identify genetic factors that confer susceptibility to specific side effects and to predict good/poor therapeutic response. It should be possible for clinician to select most appropriate drug for individual based on this study.
Pharmacogenetics
These collectively contribute to bioavailability (5)
Pharmacokinetic Factors/Components of DrugAction
- Routes of administration
- Absorption and distribution
- Binding
- Inactivation
- Excretion
Scientific Study of the actons of drugs and their effects on a living organism
Pharmacology
2 drugs act in distinct ways but interact in a way that reduce each other’s effectiveness.
One may act on receptors in heart to increase heart rate, and 2nd may act on distinct receptors in brain-stem to slow heart rate.
Physiological Antagonism