text: There are four principal protein targets with which drugs can interact:
  * Enzymes (e.g. neostigmine and acetyl cholinesterase)
  ** Inhibitors
  ** Inducers 
  ** Activators 
  * Membrane carriers [<nowiki/>Reuptake vs Efflux] (e.g. tricyclic antidepressants and catecholamine uptake-1)
  ** Enhancer (RE)
  ** Inhibitor (RI)
  ** Releaser (RA)
  * Ion channels (e.g. nimodipine and voltage-gated Ca channels)
  ** Blocker
  ** Opener
  * Receptor (e.g. Listed in table below)
  ** Agonists can be full, partial or inverse.
  ** Antagonists can be competitive, non-competitive, or uncompetive.
  ** Allosteric modulator can have 3 effects within a receptor. One is its capability or incapability to activate a receptor (2 possibilities). The other two are agonist affinity and efficacy. They may be increased, decreased or unaffected (3 and 3 possibilities).
  NMBD = neuromuscular blocking drugs; NMDA = N-methyl-d-aspartate; EGF = epidermal growth factor.