Steady state concentration of a drug is achieved in:-

STEADY STATE - If fixed dose of a drug is administered after regular intervals, its plasma concentration stas increasing. - However, as plasma concentration rises, rate of elimination also stas increasing. When rate of administration becomes equal to rate of elimination, plasma concentration stabilizes. This is called steady state. - Time to reach steady state depends on t 1/2 . It takes approximately 4-5 half lives. - Steady state plasma concentration achieved depends on dose rate. - Variation between peak and trough concentration at steady state depends on dosing interval. However, average steady state plasma concentration remains same irrespective of dosing interval provided dose rate remains same.