History of Pharmacology and Principles of Pharmacokinetics and Pharmacodynamics

A comprehensive set of vocabulary flashcards covering the history of pharmacology from ancient eras to the modern day, including core principles of pharmacokinetics, pharmacodynamics, and various routes of drug administration.

Pharmacology

Branch of medicine that pertains to treating diseases, illnesses and sickness.

Drugs

Substances that can alter biological functions.

Medicine

Substances intended to treat diseases that promote health.

Diseases

Medical conditions due to pathogens, such as HIV.

Illnesses

Conditions caused by a deviation of normal function.

Sickness

Physical manifestations of disease or illness, or the feeling of being unwell.

Ebers Papyrus

An Egyptian document from approximately $1550\text{ BCE}$ that documented hundreds of remedies, including opium and willow bark.

Humoral theory

A theory by Galen ($129\text{--}200\text{ CE}$) attributing disease to an imbalance of blood, phlegm, yellow bile, and black bile.

William Harvey ($1578\text{--}1657$)

Demonstrated the circulation of blood, providing the foundation for understanding drug distribution.

Pharmacokinetics

The study of how the body handles drugs, summarized by the acronym ADME: Absorption, Distribution, Metabolism (biotransformation), and Excretion.

Enteral

A route of drug administration involving the gastrointestinal tract, such as the esophagus.

Parenteral

A route of drug administration via prick or injection, including intramuscular, subcutaneous, intradermal, or intravenous routes.

EPAL Mnemonic

A classification for anesthesia: ESTHER metabolized in PLASMA ($1$ 'i' in the word) and AMIDE metabolized in the LIVER ($2$ 'i's in the word).

François Magendie ($1783\text{--}1855$)

The founder of experimental physiology who studied drug effects on animals.

Claude Bernard ($1813\text{--}1878$)

Demonstrated site-specific drug action, such as the effect of curare at the neuromuscular junction.

Friedrich Sertürner ($1783\text{--}1841$)

Isolated morphine from opium in $1805$, marking the start of alkaloid chemistry.

Pharmacodynamics

The study of how drugs affect the body.

Pharmacogenomics

The study of the response of drugs relative to an individual's genetic make-up.

Adverse Effects

Drug effects that are life-threatening.

Side Effects

Drug effects that are not life-threatening.

Paul Ehrlich ($1854\text{--}1915$)

Introduced the "magic bullet" concept and developed Salvarsan ($1910$) for syphilis.

Otto Loewi ($1873\text{--}1961$)

Demonstrated chemical neurotransmission in $1921$ through the "vagusstoff" experiment.

Sir Austin Bradford Hill ($1897\text{--}1991$)

Designed randomized controlled trials, forming the foundation of evidence-based pharmacology.

James Black ($1924\text{--}2010$)

Developed propranolol ($\beta$-blocker) and cimetidine ($H_2$ antagonist); awarded the Nobel Prize in $1988$.

Occupational Theory

The theory that the more receptors are occupied, the more effective the drug is.

Agonist

A substance with affinity (ability to attach) and intrinsic activity (ability to produce an effect).

Antagonist

A substance with affinity that can bind to a receptor but has no intrinsic activity and cannot produce an effect.

Drug Size Range

Most drugs have a molecular weight ($MW$) between $100$ and $1000$.

Therapeutic Index ($TI$)

A safety margin calculated as the ratio $\frac{TD_{50}}{ED_{50}}$, where $TD_{50}$ is the toxic dose and $ED_{50}$ is the effective dose.

Ligand-gated ion channels

Receptors that act in milliseconds, such as the nicotinic ACh receptor.

G-protein coupled receptors (GPCRs)

Receptors that act in seconds, such as adrenergic receptors.

Inert Binding Sites

Nonfunctional binding sites like albumin that influence drug distribution and half-life but do not mediate a therapeutic effect.

First-pass effect

The hepatic metabolism of a pharmacological agent when it is absorbed from the gut and delivered to the liver via the portal circulation before reaching systemic circulation.

Bioavailability

The fraction of an unchanged drug that reaches the systemic circulation; it is $100\text{\textsf{\%}}$ for intravenous administration.

Volume of Distribution ($V$)

An apparent volume that relates the total amount of drug in the body to the concentration of drug ($C$) in blood or plasma.

Clearance ($CL$)

The ability of the body to eliminate a drug, representing the sum of renal, hepatic, and other organ clearances.

Half-life ($t_{1/2}$)

The time necessary to reduce the amount of medication in the body by half during elimination.

Steady-state concentration

The drug concentration reached when the rate of drug administration equals the rate of elimination, typically achieved after approximately four half-lives.

Potency

The amount of drug needed to produce a given effect.

Efficacy

The maximal effect that a drug produces irrespective of its concentration.

Intrathecal Injection

A route used for drugs that cannot cross the blood-brain barrier ($BBB$).