PHA6120: Special Topics

Clinical Pharmacokinetics

drug’s movement through the body

body

Clinical Pharmacokinetics

what the _ does to (or with) the drug

toxicity

Clinical Pharmacokinetics

achieve efficacy without _

therapeutic window

Clinical Pharmacokinetics

plasma concentration (Cp) within the ‘_’

TDM and Individualization

Clinical Pharmacokinetics

Application of _ of drug therapy

Toxicity

Dosing too high in relation to the patient’s CL

Drug may be ineffective

Dosing too low in relation to the patient’s CL

Half-life (T1/2)

Important Clinical Pharmacokinetic Parameters

Time to steady state and the dosing interval

Volume of Distribution (Vd)

Important Clinical Pharmacokinetic Parameters

Loading dose

Clearance (CL)

Important Clinical Pharmacokinetic Parameters

Maintenance dose rate

Steady-State Concentration (Css)

The rate of drug leaving the body is equal to the rate of drug entering the body

more than 95%

For therapeutic purposes, the time for the plasma drug concentration to reach _ of the steady-state drug concentration in the plasma is often estimated

five

Steady-state occurs after a drug has been given for approximately _ elimination half-lives

imposable

At steady-state, the rate of drug administration equals the rate of elimination and plasma concentration - time curves found after each dose should be approximately super _.

interpreting

Important is Css when _ drug concentrations in TDM or assessing clinical response

zero order

IMPORTANCE OF CSS
If the elimination will follow _ not the first order

input

IMPORTANCE OF CSS

Rate of _ > rate of elimination

increase

IMPORTANCE OF CSS

There will be continuous _ in Cp

Steady state

IMPORTANCE OF CSS

_ will not be reached

loading dose (LD)

If immediate effect is needed, a _ must be given

loading dose (LD)

It is administered at the start of a dosage regimen to achieve

effective Cp rapidly

initial

Loading dose can produce an _ blood level either slightly higher or lower than C ss.

high

Multiple small loading doses or intermittent IV infusion may be needed to prevent Cp from becoming too _

fluctuations

If large doses are given at wider dosage intervals, wide _ will occur

Maintenance Dose (MD)

Dose required to obtain a given stead-state plasma concentration (Css)

Maintenance Dose (MD)

obtained from Clearance (Cl)

sustain

Maintenance Dose (MD)

Intended to _ a certain plasma concentration

constant

Maintenance Dose (MD)

Administered as a _ rate infusion

longer

Maintenance Dose (MD)

Drugs with _ elimination half-life (levothyroxine, Oral contraceptives)

minimal consequence

Maintenance Dose (MD)

For missed doses, _ since small fraction of drug is lost

as soon as

Maintenance Dose (MD)

Take the next dose _ patient remembers

should not be taken

Maintenance Dose (MD)

If almost time for next dose, skipped dose _, follow regular dosing schedule

controlled

Maintenance Dose (MD)

Used of _ release formulations