### T07) Find t from Ct, C0 and k

50. Pharmacokinetics 50.2) Plasma concentrations over time 50.2.1) Plasma concentrations over time

T01: Later plasma concentration Normal 1

Total tried:       Correct:       Wrong:

A patient (169 Kg) is receiving an IV bolus administration of a drug. The plasma concentration was found to be 4.96 mg/L, when the blood was first collected. If the drug follows a first order elimination and the elimination rate constant (k) is 0.107 h-1, then how long will it take to reach the plasma concentration to 1.955 mg/L? Click on the button below to see the answer and explanations

Notice: Undefined variable: input_value1 in /home/jshzub/web/rxcal.org/public_html/practice/practice/includes/body.php on line 220
lb equals 8.7 h kg

For a first order process,
C_{t}=C_{0}×e^(-kt)
It may be re-organized as:
ln(C_{t})=ln(C_{0})-kt
\implies t = ln(C_{0}/C_{t})/k
Plugging values in this equation,
t =(ln(4.96/1.955))/0.107
Or, t = 8.7
Thus, required time is 8.7 \quad h.(Ans).

#### 123 ,Lorem Ipsum dummy Text E-mail: [email protected]

Notice: Undefined index: TOTALTRY in /home/jshzub/web/rxcal.org/public_html/practice/practice/includes/body.php on line 675