Pharmacodynamics

Primary drug targets - receptors

Drugs bind to receptor via lock and key, not every drug can bind to every receptors - selectivity

Agonist (receptors)

Binds to receptor and produces same response as endogenous ligand

Antagonist (receptors)

Binds to receptor without eliciting a response, prevent endogenous ligand from binding 

Efficacy (receptors)

The extent to which we see an effect once the drug is bound to a receptor

Primary drug targets - ion channels

Either physically blocking an open ion channel or binding to a receptor that governs an ion channel

Primary drug targets - carrier molecules

Blocks carrier molecule from transport substance it carries

Primary drug targets - enzymes - competitive inhibitors

Drug and substrate compete for active site on enzyme

Primary drug targets - enzymes - non competitive inhibitors

Drug distorts enzyme shape or damaged enzyme