MTM Drug Therapy Monitoring & Clinical Decision-Making 2 — Questions and Answers
Question 1: A patient on warfarin has an INR of 4.8 with no signs of bleeding. What is the most appropriate clinical action?
- Discontinue warfarin permanently
- Hold 1-2 doses and recheck INR in 1-2 days (Correct answer)
- Administer vitamin K 10 mg IV immediately
- Continue current dose and recheck in 1 week
Correct answer: Hold 1-2 doses and recheck INR in 1-2 days
For supratherapeutic INR (4.5-10) without bleeding, holding 1-2 doses and rechecking INR in 24-48 hours is the standard approach.
Question 2: Which serum creatinine-based equation is preferred for adjusting medication doses in patients with chronic kidney disease?
- Cockcroft-Gault
- MDRD (Modification of Diet in Renal Disease)
- CKD-EPI creatinine equation (Correct answer)
- Jelliffe equation
Correct answer: CKD-EPI creatinine equation
The CKD-EPI creatinine equation provides the most accurate GFR estimate for CKD staging and is preferred by major nephrology guidelines.
Question 3: A patient with type 2 diabetes has an A1C of 9.2% on metformin monotherapy. Which add-on agent provides the greatest A1C reduction while minimizing hypoglycemia risk?
- Glipizide
- Semaglutide (Correct answer)
- Sitagliptin
- Pioglitazone
Correct answer: Semaglutide
GLP-1 receptor agonists like semaglutide provide 1.5-2% A1C reduction with low hypoglycemia risk and additional cardiovascular benefits.
Question 4: Which laboratory finding most urgently warrants discontinuation of an ACE inhibitor?
- Serum potassium of 5.5 mEq/L
- Serum creatinine increase of 15% from baseline
- Serum potassium of 6.5 mEq/L with ECG changes (Correct answer)
- Persistent dry cough for 2 weeks
Correct answer: Serum potassium of 6.5 mEq/L with ECG changes
Severe hyperkalemia (≥6.0 mEq/L) with ECG changes represents a life-threatening emergency requiring immediate ACE inhibitor discontinuation.
Question 5: When monitoring a patient on amiodarone long-term, which organ system requires the MOST frequent surveillance due to potentially irreversible toxicity?
- Kidneys (serum creatinine every 3 months)
- Thyroid (TFTs every 6 months) (Correct answer)
- Liver (LFTs every 6 months)
- Pulmonary (chest X-ray annually)
Correct answer: Thyroid (TFTs every 6 months)
Amiodarone contains 37% iodine by weight and causes thyroid dysfunction in up to 14% of patients, requiring TFT monitoring every 6 months.
Question 6: A patient on lithium presents with coarse tremor, confusion, and nausea. Serum lithium level is 1.9 mEq/L. What is the priority intervention?
- Reduce lithium dose by 50% and add propranolol for tremor
- Hold lithium and provide aggressive IV hydration (Correct answer)
- Switch to valproate immediately
- Add an antiemetic and continue current lithium dose
Correct answer: Hold lithium and provide aggressive IV hydration
Lithium toxicity (therapeutic range 0.6-1.2 mEq/L) requires immediate drug discontinuation and IV saline to promote renal lithium excretion.
Question 7: Which clinical parameter is the BEST surrogate marker for monitoring response to statin therapy in a high-risk cardiovascular patient?
- Total cholesterol reduction to <200 mg/dL
- Percent reduction in LDL-C from baseline (Correct answer)
- Achievement of LDL-C <70 mg/dL
- HDL-C increase above 40 mg/dL
Correct answer: Percent reduction in LDL-C from baseline
Current ACC/AHA guidelines emphasize percent reduction in LDL-C (≥50% for high-intensity statins) as the primary monitoring parameter rather than absolute targets.
MTM Drug Therapy Monitoring & Clinical Decision-Making 2
A patient on warfarin has an INR of 4.8 with no signs of bleeding.
What is the most appropriate clinical action?