<prompt> Maintenance dose depends on -ClearanceVolume of distributionMetabolismAbsorption  <response>: Ans. is a i.e., ClearanceDrug dosingo For drugs with longer t 12 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 delaye 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 dose This is single or few quickly repeated doses given in the beginning to attain target concentration rapidly.o Maintenance dose This 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.o 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 tVi.o The drug with short tVi with loading and maintenance dose concept -Lignocaine. 