Kpharma Posted June 5, 2006 Share Posted June 5, 2006 Ten hours after 750mg of a drug is administered by iv injection a plasma con is 20mcg/ml If the half life of the drug is 5 hours and the MEC is 3mcg/ml how many hours after the first dose should the second dose be administered? 10hrs -------------20 15hrs -----------10 20 ------------ 5 25 ---------- 2.5 so it must be between 20 and 25 Am i correct but the answer is given as 37.5 Please correct me if i am wrong Quote Link to comment Share on other sites More sharing options...
KingTuT Posted June 5, 2006 Share Posted June 5, 2006 :tup:i think u r correct Kpharma:tup: Quote Link to comment Share on other sites More sharing options...
Beau Posted June 5, 2006 Share Posted June 5, 2006 hi please show how you computed for it thanks Quote Link to comment Share on other sites More sharing options...
KingTuT Posted June 5, 2006 Share Posted June 5, 2006 after 5 h after 5 h after 5 h 20---->10------->5--------->2.5 BUT the min concn is 3 not 2.5 ...i e it will take more than 10 h but less than 15 h for the concn 2 decrease from 20 to 3 BUT dont forget that the concn became 20 after 10 h of adminestration so the time between the 1st & 2nd =10+(some thing between 10 & 15)=between 20 & 25 . I HOPE IT IS CLEAR please let me know if u have any problem . hey Kpharm the answer will b 37.5 if the t1/2 is 10 h good luck Quote Link to comment Share on other sites More sharing options...
cancan Posted June 5, 2006 Share Posted June 5, 2006 Hi I can't understand.We should take t1/2=5 hours or t1/2=10 hours?? Coulde you please explain one more time. Thanks. Quote Link to comment Share on other sites More sharing options...
KingTuT Posted June 5, 2006 Share Posted June 5, 2006 in this question we take t1/2 5h . i was just saying that the answer would b 37.5 if we usad t1/2 =10 h u can try it urself . sorry if my speach was vague guys. Quote Link to comment Share on other sites More sharing options...
cancan Posted June 5, 2006 Share Posted June 5, 2006 Thanks KingTut, There is nothing wrong on you.You explans very well.My brain dosen't work anymore i guess. Quote Link to comment Share on other sites More sharing options...
pujitha Posted June 5, 2006 Share Posted June 5, 2006 plz expalin this 6 hours after 500mg is administered,plasma conc is 10mg/ml.if t1/2 is 4 hours and MEC is 2mg/ml.how many hrs after first dose sud a second be administered. Quote Link to comment Share on other sites More sharing options...
jak073 Posted June 5, 2006 Share Posted June 5, 2006 plz expalin this 6 hours after 500mg is administered,plasma conc is 10mg/ml.if t1/2 is 4 hours and MEC is 2mg/ml.how many hrs after first dose sud a second be administered. --------------- time dose left 6hr 10mg/ml 10 hr 5 14 2.5 18 1.75 so the first dose must be given between or before 14-18 hours after the first (beacuse we dont want to be go below MEC which is required for hte drug to be effective in its action) hope that helps. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.