Healthy adult volunteers are enrolled in a phase I clinical trial investigating the properties of a newly developed oral antimicrobial agent. The drug is administered in different amounts to the volunteers over the course of several weeks to determine the best dosage that minimizes toxicity while maintaining trough levels above the minimum inhibitory concentration. While reviewing the data, the researchers note that the drug's half-life seems to vary amongst the study participants. An increase in which of the following pharmacologic parameters is most likely responsible for the longer half-life seen in certain individuals?

Question

Healthy adult volunteers are enrolled in a phase I clinical trial investigating the properties of a newly developed oral antimicrobial agent.  The drug is administered in different amounts to the volunteers over the course of several weeks to determine the best dosage that minimizes toxicity while maintaining trough levels above the minimum inhibitory concentration.  While reviewing the data, the researchers note that the drug's half-life seems to vary amongst the study participants.  An increase in which of the following pharmacologic parameters is most likely responsible for the longer half-life seen in certain individuals?

Quizplus · Accepted Answer

Eductional Objective: Half-life (t1/2) is a measure of how quickly a drug with first-order kinetics is eliminated from the body. A drug is almost completely eliminated after 5 half-life intervals. The half-life can be calculated from the drug's volume of distribution (Vd) and clearance rate (CL) using the following equation:
t1/2 = (0.7 × Vd) / CL.

Healthy Adult Volunteers Are Enrolled in a Phase I Clinical