Questions: A nurse is preparing to administer famotidine 1 mg / kg / day PO divided equally every 12 hr to a child who weighs 41 lb. Available is famotidine oral suspension 40 mg / 5 mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

A nurse is preparing to administer famotidine 1 mg / kg / day PO divided equally every 12 hr to a child who weighs 41 lb. Available is famotidine oral suspension 40 mg / 5 mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Transcript text: A nurse is preparing to administer famotidine $1 \mathrm{mg} / \mathrm{kg} /$ day PO divided equally every 12 hr to a child who weighs 41 lb . Available is famotidine oral suspension $40 \mathrm{mg} / 5 \mathrm{~mL}$. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Solution

Solution Steps

To solve this problem, we need to follow these steps:

Convert the child's weight from pounds to kilograms.
Calculate the total daily dose of famotidine in milligrams.
Determine the dose per administration (since the medication is given every 12 hours, there are 2 doses per day).
Convert the dose per administration from milligrams to milliliters using the concentration of the oral suspension.
Round the final answer to the nearest tenth.

Step 1: Convert Weight from Pounds to Kilograms

To convert the child's weight from pounds to kilograms, we use the conversion factor $ 1 \, \text{lb} = \frac{1}{2.20462} \, \text{kg} $: \[ \text{Weight in kg} = 41 \, \text{lb} \times \frac{1}{2.20462} \approx 18.5973 \, \text{kg} \]

Step 2: Calculate Total Daily Dose in Milligrams

The total daily dose of famotidine is calculated using the formula: \[ \text{Total Daily Dose (mg)} = \text{Weight (kg)} \times 1 \, \text{mg/kg/day} = 18.5973 \, \text{kg} \times 1 \, \text{mg/kg/day} \approx 18.5973 \, \text{mg} \]

Step 3: Calculate Dose per Administration

Since the medication is administered every 12 hours, there are 2 doses per day: \[ \text{Dose per Administration (mg)} = \frac{\text{Total Daily Dose (mg)}}{2} = \frac{18.5973 \, \text{mg}}{2} \approx 9.2987 \, \text{mg} \]

Step 4: Convert Dose per Administration from Milligrams to Milliliters

The concentration of the famotidine oral suspension is given as $ 40 \, \text{mg} / 5 \, \text{mL} $, which simplifies to: \[ \text{Concentration} = \frac{40 \, \text{mg}}{5 \, \text{mL}} = 8 \, \text{mg/mL} \] Now, we can convert the dose per administration from milligrams to milliliters: \[ \text{Dose per Administration (mL)} = \frac{\text{Dose per Administration (mg)}}{\text{Concentration (mg/mL)}} = \frac{9.2987 \, \text{mg}}{8 \, \text{mg/mL}} \approx 1.1623 \, \text{mL} \]

Step 5: Round the Final Answer

Rounding the dose per administration to the nearest tenth gives: \[ \text{Dose per Administration (mL)} \approx 1.2 \, \text{mL} \]