Dismiss Notice
Hey Texans—join us for a DFW meetup! Click here to learn more.

Question on pharmacokinetics

Discussion in 'Pharmacy Licensure and Exams' started by hamza1892, Aug 16, 2015.

  1. hamza1892

    2+ Year Member

    Joined:
    Dec 23, 2011
    Messages:
    16
    Likes Received:
    1
    Status:
    Pharmacy Student
    If a patient was given 250mg of gentamicin at 6am and then drew a level at 12pm and it was 12 and then 5pm you check the level again it was 7.. how would you find the half-life of gentamicin???


    thank you for your responses in advance
     
  2. Note: SDN Members do not see this ad.

  3. sgkman

    Joined:
    Jul 26, 2015
    Messages:
    12
    Likes Received:
    2
    MDApps:
    MDApps:
    Status:
    Pharmacist
    Use C2 = C1 E^-ke*t equation to find Ke and do 0.693/ke to get half life.

    In this case:

    12=250e^(-ke)(6)

    ln(12/250) = -ke * 6

    find Ke and plug in half life equation.
     
  4. succulents222

    Joined:
    Jul 26, 2015
    Messages:
    1
    Likes Received:
    0
    Status:
    Pharmacy Student
    C1 = 12
    C2= 7
    Time (Difference in time between two levels) = 12pm - 5pm = 5 hrs
    7= 12 x e^(-ke(5))= ln (7/12)/-5 = ke
    Half life = 0.693/ke
    Answer= 6.4 hrs
     
  5. confettiflyer

    confettiflyer Did you just say something?
    10+ Year Member

    Joined:
    Dec 19, 2004
    Messages:
    9,146
    Likes Received:
    2,325
    Status:
    Pharmacist
    at this point I'd eyeball it and say ~6hrs (12->7 is almost 12->6 therefore the half-life is no less than 5hrs and probably 6-7).
     
  6. hamza1892

    2+ Year Member

    Joined:
    Dec 23, 2011
    Messages:
    16
    Likes Received:
    1
    Status:
    Pharmacy Student
    Thank you, everyone for your answers! I really appreciate it :)
     

Share This Page