A patient is administered 300 mg of a certain drug every 3 hours. The half-life of the drug in the body is 188.4 minutes. Determine the amount of drug that remains immediately after the patient takes the th dose.
+23254 I'm assuming that you meant "takes the third dose".
Formula for half-life: F = I·(½)^(t/h)
F = final amount I = initial amount t = time h = half-life
The second dose will be taken 3 hours after the first dose and the third dose will be taken 6 hours after the first dose.
For the initial 300 mg dose after 6 hours (360 minutes): F = 300·(½)^(360/188.4) = 79.78 mg
For the second 300 mg dose after 3 hours (180 mins): F = 300·(½)^(180/188.4) = 154.71 mg
For the third dose (just taken): F = 300 mg.
Total: 79.78 mg + 154.71 mg + 300 mg = 534.49 mg
+23254 I'm assuming that you meant "takes the third dose".
Formula for half-life: F = I·(½)^(t/h)
F = final amount I = initial amount t = time h = half-life
The second dose will be taken 3 hours after the first dose and the third dose will be taken 6 hours after the first dose.
For the initial 300 mg dose after 6 hours (360 minutes): F = 300·(½)^(360/188.4) = 79.78 mg
For the second 300 mg dose after 3 hours (180 mins): F = 300·(½)^(180/188.4) = 154.71 mg
For the third dose (just taken): F = 300 mg.
Total: 79.78 mg + 154.71 mg + 300 mg = 534.49 mg
