Pharmacokinetic/Pharmacodynamic Correlation in drug therapy

CLINICAL PHARMACOKINETICS & PHARMACOTHERAPEUTIC DRUG MONITORING

UNIT-4

Therapeutic Drug monitoring: 

Pharmacokinetic/Pharmacodynamic Correlation in drug therapy.

 

Get the notes below!

Concentration of a therapeutic drug is measured in the serum or plasma.

 Whole blood concentration of immunosuppressant drugs such as

cyclosporine and tacrolimus is usually measured for therapeutic drug

monitoring.

 Obtaining blood for measurement of a drug during the absorption or the

distribution phase may lead to misleading information.

 To measure the peak concentration of a drug, timing of the sample will

depend on the route of administration.

 After intravenous administration, the peak concentration of a drug may be

achieved in a few minutes. On the contrary, for a sustained release tablet,

the mean time to reach the peak plasma

 concentration will be more.

 The trough concentration is clinically defined as the serum drug

concentration just before the next dose. Usually, trough concentrations

are monitored for most drugs, but for aminoglycosides and

 vancomycin, both peak and trough concentrations are monitored.

 For a meaningful interpretation of a serum drug concentration, time of

specimen collection should be noted along with the time and date of the

last dose and route of administration of the drug.

 This is particularly important for aminoglycoside because without

knowing the time of specimen collection, the serum drug concentration

cannot be interpreted.

Pharmacokinetic/Pharmacodynamic Correlation in drug therapy.