The dose of induction agent required for a fit, adult patient depends on the chosen agent. These doses may be reduced if other adjuvant drugs, such as opioids or benzodiazepines, are given simultaneously:

• For propofol: 1-2.5 mg/kg
• For thiopental: 3-7 mg/kg
• For etomidate: 0.25-0.3 mg/kg

Each drug is given slowly and titrated to clinical effect, usually the loss of the eyelash reflex. Onset time is rapid because the agents cross the blood-brain barrier quickly due to their high lipid solubility.

The brain is the major effect site, i.e. the central nervous system (CNS) but other systems are affected by induction agents, particularly the cardiovascular (CVS) and respiratory systems (RS).