4) IV Bolus Questions with 100% correct
answers. NEW UPDATE!!
When is a loading dose most necessary? - CORRECT ANSWER-For drugs that
have a long half-life, since the time to steady state is longer. Need to achieve
therapeutic dose right away
Why do bolus and short-infusion graphs look different? - CORRECT ANSWER-
Bolus: concentration goes up instantaneously; Short infusion: curved initial dose - not
peaked - because of drug loss during infusion time.
When should one choose a bolus administration? When is short infusion preferable? -
CORRECT ANSWER-Tin (time infusion) is < 1/6 half-lifes = bolus. If Tin > 1/6
half-lifes, use a short infusion.
What are three characteristics of the one-compartment open model? - CORRECT
ANSWER-Drugs can enter or leave the body, and the body acts as a single, uniform
compartment; distribution occurs instantaneously and homogenously; elimination occurs
immediately after injection by a first order process
What characterizes IV bolus administration? - CORRECT ANSWER-Drug is
injected all at once into the compartment.
How is Co defined? What is it dependent on? What is the bolus equation to calculate
Concentration at time "t" (after bolus admin)? - CORRECT ANSWER-Co = Dose
/ Vd. Initial concentraion following IV bolus is based on these factors. Cp vs time afer IV
bolus admin: Ct = (Dose / Vd) * e^(-kt), where k is a dependent paramter k = CL/Vd,
implying that Ct is dependent on Dose and Vd (thus, Co), as well as Clearance.
What determines initial pk parameters for dose? - CORRECT ANSWER-
Population estimates (prior published studies)
How are individualized (revised) pk parameter estimates determined? - CORRECT
ANSWER-Measurement of plasma concentrations and applying a model to the data.
How is Vd defined? - CORRECT ANSWER-Vd is determined by Dose / Co
(reorganization of Co = Dose/ Vd).
What is the expression that descibes the plasma concentration time profile for a mono-
exponential one-compartment model where t = time between C1 and C2? How can this
