After six half-lives, how much of a drug remains in the body?

After six half-lives, how much of a drug remains in the body?

• A. 50% clearance, 50% remains in the body
• B. 75% clearance, 25% remains in the body
• C. 87.5% clearance, 12.5% remains in the body
• D. 98.43% clearance, 1.56% remains in the body

Answer: (D)

After six half-lives, the amount of a drug remaining in the body can be determined using the half-life concept, which states that after each half-life, half of the remaining drug is eliminated from the body. This leads to a predictable decrease in drug concentration. To break down the process: 1. After the first half-life, 50% of the drug remains. 2. After the second half-life, 25% remains (half of 50%). 3. After the third half-life, 12.5% remains (half of 25%). 4. After the fourth half-life, 6.25% remains (half of 12.5%). 5. After the fifth half-life, 3.125% remains (half of 6.25%). 6. After the sixth half-life, 1.5625% remains (half of 3.125%). Rounding 1.5625% gives approximately 1.56%. Consequently, this means that after six half-lives, 98.44% of the drug has been cleared from the body. This understanding illustrates why the correct choice indicates that 98.43% clearance corresponds to 1.56% remaining in

After six half-lives, the amount of a drug remaining in the body can be determined using the half-life concept, which states that after each half-life, half of the remaining drug is eliminated from the body. This leads to a predictable decrease in drug concentration.

To break down the process:

1. After the first half-life, 50% of the drug remains.

2. After the second half-life, 25% remains (half of 50%).

3. After the third half-life, 12.5% remains (half of 25%).

4. After the fourth half-life, 6.25% remains (half of 12.5%).

5. After the fifth half-life, 3.125% remains (half of 6.25%).

6. After the sixth half-life, 1.5625% remains (half of 3.125%).

Rounding 1.5625% gives approximately 1.56%. Consequently, this means that after six half-lives, 98.44% of the drug has been cleared from the body.

This understanding illustrates why the correct choice indicates that 98.43% clearance corresponds to 1.56% remaining in