Maintainence dose is calculated by using value of-

Ans. is 'a' i.e., Clearance Drug dosingo For drugs with longer t 1/2 a dose that is sufficient to attain the target concentration after single administration, if repeated will accumulate according to plateau principal and produce toxicity later on.o On the other hand, if the dosing is such as to attain target level at steady state, the therapeutic effect will be delayed by about 5 half lives and this lapse of time may be undesirable some time,o Such drugs are often administered by initial loading dose and subsequent maintenance doses.o Loading doseThis is single or few quickly repeated doses given in the beginning to attain target concentration rapidly.Target Cp x Volume of distributionLoading dose = ------------------------------------------------------------------Fo Maintenance doseThis dose is one that is to be repeated at specific intervals after the attainment of target steady state plasma concentration (Cpss) so as to maintain the same by balancing elimination.Target Cpss x CLMaintenance dose rate =------------------------------------------------------Fo Such two phase dosing (Loading and maintenance) is used in :# Digoxin# Doxycycline# Long acting sulfonamides# Chloroquine# Phenylbutazone Remembero Loading dose is governed by volume of distribution.o Maintenance dose is governed by clearance or t 1/2 .o The drug with short tZz with loading and maintenance dose concept - Lignocaine.