Questions: A doctor prescribes ampicillin 40 mg / kg to a patient weighing 55 lbs. Ampicillin is available as 500 mg tablets. How many tablets should the nurse administer?
Transcript text: (2 points) A doctor prescribes ampicillin $40 \mathrm{mg} / \mathrm{kg}$ to a patient weighing 55 lbs . Ampicillin is available as 500 mg tablets. How many tablets should the nurse administer?
Solution
Solution Steps
Step 1: Convert Weight to Kilograms
To convert the patient's weight from pounds to kilograms, we use the conversion factor \( 1 \text{ lb} = 0.453592 \text{ kg} \). Thus, the weight in kilograms is calculated as:
\[
\text{weight}_{\text{kg}} = 55 \text{ lbs} \times 0.453592 \text{ kg/lb} \approx 24.94756 \text{ kg}
\]
Step 2: Calculate Total Dosage Required
The prescribed dosage of ampicillin is \( 40 \text{ mg/kg} \). Therefore, the total dosage required in milligrams is given by:
\[
\text{total dosage}_{\text{mg}} = \text{weight}_{\text{kg}} \times 40 \text{ mg/kg} \approx 24.94756 \text{ kg} \times 40 \text{ mg/kg} \approx 997.9024 \text{ mg}
\]
Step 3: Determine Number of Tablets Needed
Ampicillin is available in 500 mg tablets. To find the number of tablets required, we divide the total dosage by the dosage per tablet:
\[
\text{num tablets} = \frac{\text{total dosage}_{\text{mg}}}{500 \text{ mg}} \approx \frac{997.9024 \text{ mg}}{500 \text{ mg}} \approx 1.9958048
\]
Since the nurse cannot administer a fraction of a tablet, we round up to the nearest whole number, resulting in:
\[
\text{num tablets rounded} = 2
\]