<prompt> The pharmacokinetic propeies of a new antihistamine are being studied in normal volunteers during phase I clinical trials. The clearance and half-life of the drug are determined to be 4.0 Lhour and 10 hours, respectively. Which of the following values is the approximate volume of distribution for this drug?0.06 L14 L45 L60 L  <response>: The volume of distribution of a drug can be determined using the following equation: t12 0.693 x VdCL Therefore, 10 hours 0.693 x Vd4.0 Lhour, 40 hours 0.693 x Vd, Vd 58 L which is approximately 60 L. 