Week 1- TDM

Question 1

why do wedo therapeuticic drug monitoring?

Answer 1

• to find out what will happen to a patient to do with efficacy and toxicity
• allows us to Links measurement of serum drug
  concentrations with clinical pharmacokinetics
  -allows drug therapy to be indivualised to optimise treatment and have the optimum therapeutic benefits without drug toxicity and by preventing side effects

Question 2

which drugs have Therapeutic
Drug
Monitoring(TDM) ?

Answer 2

-not all drugs
-when using drugs that have a small therapeutic window

Question 3

why is it important to indivualise medication that need TDM?

Answer 3

as some patients may see therapeutic benefits even below the Therapeutic range

Question 4

which drugs are suitable for TDM?

Answer 4

-Aminoglycoside antibiotics
*Gentamicin, amikacin, netilmicin, tobramycin
-Anticonvulsants
*Phenytoin, [carbamazepine, (valproic acid), phenobarbitone]
-Digoxin
-Ciclosporin and Tacrolimus
-Lithium
-Theophylline
-Glycopeptide antibiotics
*Vancomycin, [teicoplanin]

Question 5

what are the indications for measuring plasma drug concentration

Answer 5

-to assess the therapeutic effect and indivualised therapy
-adherence, to check levels that are prescribed
-toxicitiy, to check symptoms are due to something else

Question 6

when is the correct time to take blood samples for TDM?

Answer 6

there’s a relationship between response and concentration based on steady-state samples taken at specific times after the dose.
-need to make sure the distribution of the drug has had enough time

Question 7

what is the therapeutic window?

Answer 7

• Conc below which therapeutic effect unlikely and above
  which toxic effect more likely
  -However, do not take as absolute:
   Some patients respond to levels below or above
   Some patients may get toxic effects at so-called “normal”
  levels

Question 8

why is population data important for TDM?

Answer 8

-Two main uses:
 Calculating doses for patients who have not yet had drug
 Checking calculations during TDM process (compare calculated pt
values with population data)

Question 9

what are some assumptions for TDM?

Answer 9

-Patient is fully compliant with
therapy
-Assay method reliable and
accurate
-Appropriate sampling time and
time of last dose
-IF LEVELS UNEXPECTEDLY HIGH
OR LOW ASK QUESTIONS!