MBBS · Pharmacology

Pharmacodynamics

Pharmacodynamics describes how a drug interacts with biological targets and generates effects. Concentration–response relationships depend on receptor signaling and the measured endpoint.

Open interactive lesson & self-check ↗

Pharmacodynamics — learning map

Original conceptual SVG · scalable
LABELED RELATIONSHIP MAP · SCHEMATIC, NOT TO SCALEReceptors and targetsdrug–target interactionPotencyconcentration for effectEfficacymaximum achievable responseTherapeutic indexbenefit versus harmPharmacodynamicsKEY RELATIONSHIPS

Original schematic relationship map for this topic; relationships are organized for study, not intended as an anatomical depiction or a diagnostic algorithm.

Concept 01

Receptors and targets

Agonists activate signaling; antagonists may prevent agonist action. Not every drug requires a classical receptor, as enzymes and ion channels are also targets.

Concept 02

Potency

Potency describes the amount or concentration needed for a defined response and does not by itself establish better clinical efficacy or safety.

Concept 03

Efficacy

Intrinsic activity and tissue context help determine maximal effect; a partial agonist can produce a lower maximal response than a full agonist in a given system.

Concept 04

Therapeutic index

A therapeutic window considers exposure associated with benefit and unacceptable adverse effects; monitoring needs vary by drug and patient factors.

Education / safety note: This page does not provide prescribing doses; clinical effects vary by drug, interaction, disease and population.

Reference and next reading

Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.

Official / publisher source: NMC official CBME Curriculum 2024 and current regulations index ↗Official / publisher source: NCBI Bookshelf ↗Official / publisher source: PubMed ↗