Certified Medical Assistant (CMA AAMA)PharmacologyHard
A physician orders levothyroxine 125 mcg PO daily. The pharmacy dispenses tablets labeled 0.05 mg. How many tablets should the medical assistant instruct the patient to take per dose?
- A2 tablets
- B2.5 tablets
- C0.5 tablet
- D1 tablet
Show answer & explanationAnswer & explanation
Correct answer: B. 2.5 tablets
First, ensure units are consistent. Convert 0.05 mg to mcg: 0.05 mg * 1000 mcg/mg = 50 mcg. Then, divide the ordered dose by the available dose: 125 mcg / 50 mcg/tablet = 2.5 tablets.
Why the other options are wrong
- A. Incorrect; this would be the dose if 100 mcg was ordered.
- C. Incorrect; this would be the dose if 25 mcg was ordered.
- D. Incorrect; this would be the dose if 50 mcg was ordered.
Unit Conversion in Dosage Calc
Unit conversion in dosage calculation involves converting between different units of measurement (e.g., mg to mcg, grams to milligrams) to ensure consistency before performing the final calculation.
- 1 mg = 1000 mcg.
- Always convert to the same unit before dividing.
- Accuracy in conversion is critical for patient safety.
Memory trick: Convert First, Then Divide!