A nurse is preparing to administer liquid famotidine 20 mg PO every 6 hr for GERD. Available is famotidine 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.)
Answer and Explanation
To determine the amount of liquid famotidine to administer, follow these steps:
- Identify the available concentration and the prescribed dose:
- Available concentration: 40 mg per 5 mL
- Prescribed dose: 20 mg
- Calculate the volume required for the prescribed dose:
- Use the formula: Volume=(Desired doseAvailable concentration)×Volume available\text{Volume} = \left(\frac{\text{Desired dose}}{\text{Available concentration}}\right) \times \text{Volume available}Volume=(Available concentrationDesired dose)×Volume available
- Substitute the values: Volume=(20 mg40 mg)×5 mL\text{Volume} = \left(\frac{20 \text{ mg}}{40 \text{ mg}}\right) \times 5 \text{ mL}Volume=(40 mg20 mg)×5 mL
- Calculate: Volume=2040×5=0.5×5=2.5 mL\text{Volume} = \frac{20}{40} \times 5 = 0.5 \times 5 = 2.5 \text{ mL}Volume=4020×5=0.5×5=2.5 mL
Answer: 2.5 mL
Explanation:
To administer 20 mg of famotidine from a solution that has 40 mg per 5 mL, you need 2.5 mL of the solution.