ANS. DPlasma concentration of drug varies with time follows the graph as shown below. Certain drugs can be secreted in breast milk and therefore transferred to the infant. Care should be taken to decrease this to the minimum possible levels.Least plasma concentration of the drug will be just before the next loading dose. Hence, the least chance for the drug to be concentrated in milk and thereby transferred to the infant would be at the time just before taking next dose. Hence advice mother to lactate just before taking next dosage of the drug.