The healthcare provider prescribes 0.075 mg of levothyroxine PO daily. The medication is labeled, “50 mcg tablets.” How many tablets should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth.)
The Correct Answer and Explanation is:
To determine how many tablets of levothyroxine to administer, follow these steps:
- Convert the prescribed dosage from milligrams (mg) to micrograms (mcg):
- 1 mg = 1,000 mcg
- Therefore, 0.075 mg = 0.075 × 1,000 mcg = 75 mcg
- Identify the strength of the available tablets:
- Each tablet is labeled as 50 mcg.
- Calculate the number of tablets needed:
- Use the formula: Number of tablets=Prescribed dose (mcg)Strength per tablet (mcg)\text{Number of tablets} = \frac{\text{Prescribed dose (mcg)}}{\text{Strength per tablet (mcg)}}Number of tablets=Strength per tablet (mcg)Prescribed dose (mcg)
- Substituting the values: Number of tablets=75 mcg50 mcg/tablet\text{Number of tablets} = \frac{75 \text{ mcg}}{50 \text{ mcg/tablet}}Number of tablets=50 mcg/tablet75 mcg
- This simplifies to: Number of tablets=1.5\text{Number of tablets} = 1.5Number of tablets=1.5
So, the nurse should administer 1.5 tablets of levothyroxine.
Explanation:
1. Unit Conversion:
- The prescription is in milligrams, but the tablet strength is in micrograms. Converting milligrams to micrograms is essential because it aligns with the unit used for the tablet strength. This step ensures consistency in measurement.
2. Calculation of Dosage:
- Knowing that each tablet contains 50 mcg of levothyroxine helps determine how many tablets are needed to achieve the total prescribed dose of 75 mcg. This calculation involves dividing the total required dosage by the dosage per tablet, yielding the exact number of tablets.
3. Rounding Considerations:
- In this case, the calculation yields 1.5 tablets, which is a whole number or half of a tablet. Since it’s already in a precise fractional form, no further rounding is necessary.
4. Clinical Application:
- Administering the calculated number of tablets ensures that the patient receives the exact amount of medication prescribed by the healthcare provider, which is crucial for therapeutic efficacy and safety.
Thus, based on the prescribed dosage and the tablet strength, 1.5 tablets are required to meet the prescribed dose of 75 mcg of levothyroxine.