Pharmacology - Week 15&16

Drug

a substance that, when introduced into the body, produces a biological effect. The term excludes nutrients. The terms drug, medicine, and pharmaceutical are related but subtly distinct

Medicine

is a regulated preparation of one or more drug, alongside other substances
(stabilisers, solvents, etc.), that is used as a therapy to treat, cure, prevent, or diagnose a defined condition

Biopharmaceutical

a therapeutic product that is manufactured, extracted, or semi-
synthesized, from biological sources. The term includes products that contain biologic drugs but also drug-free biologic products (e.g., stem cells, vaccines, gene therapies).

Pharmaceutical

a regulated product of the pharmaceutical industry that is used to treat, cure,
prevent, or diagnose a defined condition.

Classification of Drugs

Drugs can be classified based on their molecular structure ; the drug’s
mode of action and target , or the clinical outcome they produce

Naming of Drugs

By generic or Proprietary Name

Pharmacology

the study of how drugs act in experimental and living systems.
understanding and clinical use of drugs, as well as the discovery & development of new drugs.

Pharmacokinetics

relates to how the body deals with drugs following administration –
how drugs are delivered to the target site and how they are eliminated from the body

Pharmacodynamics

how drugs work in the body, including how they interact
with molecules, cells, or organ systems to cause their biological actions

Drug Target

is a macromolecule though which a drug directly interacts to exert its wider effects upon cells, tissues and the body

Drug Discovery and Development

Discovering a preclinical development candidate (PDC) then getting approval through clinical trials

Drug Affinity

A macromolecule though which a drug directly interacts to exert its wider effects upon cells, tissues and the body

• Affinity is dependent on the chemical interactions between the drug and target (bonding), as well as their complementary steric match (shape and size).

• Most drug-target binding occurs through non-covalent bonding, comprising van der Waals, H-bond, and electrostatic interactions.

Mechanism of Drug Action

the way in which a drug binds to its target and how this interaction
then changes the rate or magnitude of downstream cellular and physiological responses to modify biological function

Drugs can either activate, inhibit, enhance, or attenuate an intrinsic biological response

Drug Efficacy

• The ability of a drug to produce a response at the target

Agonist

alter the conformation of molecular drug target, initiating a cellular response, is referred to as the drug’s intrinsic efficacy

Antagonist

Antagonist drugs have no intrinsic efficacy – they can bind, since they have affinity, but they do not affect the conformational state of the target

Concentration-response relationship

as the concentration or dose of a drug increases, the magnitude of the response
increases from a threshold until a maximum response is obtained

Agonist Potency (EC50)

concentration that yields 50% of its maximal response (EMAX)

Intrinsic Activity (α)

maximal response of a drug as a fraction of the maximal response
of a full agonist in the same system

Full Agonist

produce the maximal known response of the system (α=1)

Partal Agonist

produce a sub-maximal response at saturating concentrations (α>0 <1)

Antagonist

zero efficacy and produce no response when tested in isolation (α=0)

Surmountable antagonist

reduce apparent agonist potency

Insurmountable Antagonist

reduce the maximum effect of an agonist, with or without effects on agonist potency