Pharma Question 1.....to jsmm and all :) - psychmledr

[ArchivalUser]

A new antifungal medication is being tested in Phase I clinical trials. Examination of the pharmacokinetic properties of the drug reveals that the half-life of the drug is 6 hours. If a continuous intravenous infusion of this drug were started on a research subject, how long would it take to reach 75% of steady state?

(A) 3 hours

(B) 6 hours

© 9 hours

(D) 12 hours

(E) 18 hours

(F) 24 hours

And please explain your answer. Thank you!

[ArchivalUser]

D.

1 t half.. meand 50%... 6 hrs

2 t half means 50% + 25% = 75%.. 6 +6 = 12hrs

[ArchivalUser]

75% stead state requires 2xhalf lives (50%->70%)
1xhalf life=6hr
2xhalf lives=6x2hrs
=> therefore 12 hours

[ArchivalUser]

C.
50% with 1 half life
75% with 1.5 half life appr.
90% with appr.3.3 half life
95% with 4-5 half life
100% with >7 half life

[ArchivalUser]

ya after 2 half life

D

[ArchivalUser]

Yep D....you're all so good...