A client who weighs 172 pounds receives a prescription for levothyroxine 1.6 mcg/kg/day by mouth. The medication is available in 50 mcg scored tablets. How many tablets should the nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
To determine the correct dosage of levothyroxine for a client who weighs 172 pounds, we must first convert the client’s weight to kilograms, as the dosage is prescribed in micrograms per kilogram per day.
Step 1: Convert the client’s weight from pounds to kilograms
1 kilogram (kg) = 2.2 poundsWeight in kg=172 pounds2.2 pounds/kg=78.18 kg\text{Weight in kg} = \frac{172 \text{ pounds}}{2.2 \text{ pounds/kg}} = 78.18 \text{ kg}Weight in kg=2.2 pounds/kg172 pounds=78.18 kg
Step 2: Calculate the total daily dosage in micrograms
The prescribed dosage is 1.6 micrograms (mcg) per kilogram per day.Total daily dose=78.18 kg×1.6 mcg/kg/day=125.088 mcg/day\text{Total daily dose} = 78.18 \text{ kg} \times 1.6 \text{ mcg/kg/day} = 125.088 \text{ mcg/day}Total daily dose=78.18 kg×1.6 mcg/kg/day=125.088 mcg/day
Step 3: Determine the number of tablets required
The available tablet strength is 50 mcg per tablet.Number of tablets=125.088 mcg/day50 mcg/tablet=2.50176 tablets\text{Number of tablets} = \frac{125.088 \text{ mcg/day}}{50 \text{ mcg/tablet}} = 2.50176 \text{ tablets}Number of tablets=50 mcg/tablet125.088 mcg/day=2.50176 tablets
Step 4: Round to the nearest tenth
The number of tablets should be rounded to the nearest tenth:2.50176≈2.5 tablets2.50176 \approx 2.5 \text{ tablets}2.50176≈2.5 tablets
Final Answer:
The nurse should administer 2.5 tablets.
Explanation:
Administering medication requires careful attention to dosage calculations, especially when converting between units and ensuring the correct dose is given. In this scenario, the client’s weight is initially provided in pounds, which must be converted to kilograms since the prescription is based on weight in kilograms. This conversion is essential because the standardized dosing of levothyroxine is commonly expressed in micrograms per kilogram.
Next, the exact dosage in micrograms is calculated by multiplying the client’s weight in kilograms by the prescribed dose per kilogram. This provides the total daily dose in micrograms. Since the medication is available in 50 mcg scored tablets, it is necessary to divide the total daily dose by the strength of each tablet to determine how many tablets are needed.
Finally, rounding is required when dealing with partial tablets. In this case, the calculated number of tablets is 2.50176, which is rounded to 2.5 tablets. The rounding process ensures that the dose is safe and accurate, balancing precision with practicality. Nurses must verify the accuracy of their calculations to ensure the client’s safety and avoid underdosing or overdosing.