CMT Treatment Planning 5

Question 1

Therapeutic drug monitoring is most valuable for drugs that have:

Accepted Answer

A narrow therapeutic index and variable pharmacokinetics

Answer

TDM is essential when small concentration changes risk toxicity or treatment failure.

Question 2

Total phenytoin levels may underestimate active drug in a patient with low albumin. Which test better guides dosing?

Accepted Answer

Free (unbound) phenytoin level

Answer

Free phenytoin reflects the pharmacologically active fraction when protein binding is altered.

Question 3

Which electrolyte abnormality increases the risk of digoxin toxicity and should be corrected during treatment?

Accepted Answer

Hypokalemia

Answer

Low potassium enhances digoxin binding to Na+/K+-ATPase, increasing toxicity.

Question 4

After a dose change, steady-state drug concentrations are generally reached after approximately how many half-lives?

Accepted Answer

4 to 5

Answer

About 4-5 half-lives are needed to reach roughly 94-97% of steady state.

Question 5

Lithium serum levels for routine dose adjustment should be drawn approximately:

Accepted Answer

12 hours after the last dose

Answer

Standardized 12-hour post-dose samples allow consistent interpretation of lithium levels.

CMT - Certified Medical Technologist Practice Test