how long does it take for plasma concentrations to reach steady state when a patient's dose is given at intervals of the drug's half-life?
âTime required for the concentration of a drug to fall to half of its initial concentration after reaching its peak.â. For example, after intravenous administration, if maximum concentration is 16 mg and the half life is 2 hours, after 2 hours 8 mg will be left, and so on. Photo by United Nations Photo. Half life of a drug is directly proportional to the volume of the distribution and inversely proportional to the clearance.