Question

Following notification of your clinical faculty, the faculty directs you to look up the pharmacokinetics of metoprolol to include the onset of action, peak of action, and half-life Your drug book states that the half-life is 3 to 7 hours, onset is 10-15 minutes, and peak in 1-2 hours after administration. Using 5 hours as a representative half-life, describe half-life and what will happen in 5 hours. What will you expect to occur at the onset and the peak of action of metoprolol?

Answer 1

Half life of a medicine is the time taken to reduce to half of its initial dose in the blood. That is, if initial dose is 250 mg then half life of the medicine is the time it become 125 mg.

In case of metoprolol, the representational half life is 5 hours, it means, by 5 hours of its administration it becomes exactly half of the initial dose.

Onset of action of metoprolol is 10 to 15 minutes, that means it starts to act in between 10 and 15 minutes.

In addition, peak of action is when the drug in its extreme level in blood to act, after this it reduced and become half of initial dose and reduces likewise.it will reduce heart rate since it is a beta blocker.