A nurse is preparing to administer erythromycin 2 g PO daily in equally divided doses every 6 hr. How many mg should the nurse administer per dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
The Correct Answer and Explanation is:
To determine how many milligrams of erythromycin the nurse should administer per dose, we start with the prescribed total daily dose and the frequency of administration.
The prescription is for 2 grams (g) of erythromycin daily, given in equally divided doses every 6 hours. First, we need to convert the daily dose from grams to milligrams, as this is the unit we will use for dosage calculation.
- Conversion of grams to milligrams:
- 1 gram = 1,000 milligrams.
- Therefore, 2 grams = 2 × 1,000 mg = 2,000 mg.
- Determining the number of doses per day:
- Since the medication is to be given every 6 hours, we can calculate how many doses there are in a 24-hour period.
- 24 hours ÷ 6 hours per dose = 4 doses per day.
- Calculating the dose per administration:
- To find out how many milligrams to administer per dose, we divide the total daily dosage in milligrams by the number of doses:
- Total daily dose (2,000 mg) ÷ Number of doses (4) = 500 mg per dose.
Thus, the nurse should administer 500 mg of erythromycin per dose.
Explanation of Rounding and Notation
In this scenario, the answer is already a whole number (500 mg), so there is no need for rounding. Additionally, the instructions specify to use a leading zero if applicable and to avoid a trailing zero. In this case, 500 mg does not require a leading zero or a trailing zero, as it is already expressed correctly.
This calculation ensures that the patient receives the full therapeutic dose of erythromycin while maintaining the recommended dosing schedule. Administering medication accurately is crucial in nursing practice to avoid underdosing or overdosing, which can lead to ineffective treatment or adverse effects, respectively.