Patient is prescribed 0.8 micrograms of levothyroxine per kilogram q 12 hours. Patient weight is 92 kilograms. How much medication should the patient be given:
Rationale: Harding, M., Kwong, J., Roberts, D., Hagler, D., & Reinisch, C. (2020). Lewis’s Medical-surgical nursing : Assessment and management of clinical problems (11th ed.,). Elsevier, Inc.
A) 153.3 mcg
B) 147.8 mcg
C) 147.2 mcg
D) 145.2 mcg
The Correct Answer and Explanation is:
To determine the correct dosage of levothyroxine for the patient, we use the following formula:
Dosage (mcg) = Dosage per kilogram × Weight (kg)
Given:
- Dosage = 0.8 micrograms/kg
- Frequency = every 12 hours
- Weight = 92 kg
Step-by-step Calculation:
0.8 μg/kg×92 kg=73.6 μg per dose0.8 \, \mu g/kg \times 92 \, kg = 73.6 \, \mu g \text{ per dose}
Since the medication is administered every 12 hours, that means the patient will receive 2 doses per day.
So, total daily dose: 73.6 μg×2=147.2 μg/day73.6 \, \mu g \times 2 = 147.2 \, \mu g/day
Correct Answer:
C) 147.2 mcg
Explanation:
Levothyroxine is a synthetic form of the thyroid hormone T4, and it is commonly prescribed for patients with hypothyroidism or after thyroidectomy. Dosing is carefully calculated based on body weight (in micrograms per kilogram) to ensure appropriate replacement of thyroid hormone.
In this case, the patient’s weight is 92 kg, and the prescribed dose is 0.8 mcg/kg every 12 hours. First, calculate the single dose:
- 0.8 mcg × 92 kg = 73.6 mcg per dose
Since the medication is to be administered twice daily (q12h), the total daily dose becomes:
- 73.6 mcg × 2 = 147.2 mcg/day
This approach ensures accurate dosing based on weight and frequency. Dosing errors can lead to either undertreatment (resulting in persistent hypothyroid symptoms such as fatigue, weight gain, and bradycardia) or overtreatment (leading to symptoms of hyperthyroidism such as palpitations, weight loss, and anxiety).
Therefore, understanding weight-based dosage calculations and frequency adjustments is critical for safe medication administration in clinical nursing practice.
Final Answer:
✅ C) 147.2 mcg