Order: diphenhydramine 25 mg PO q6h, PRN Available: diphenhydramine 12.5 mg/5 mL. How many mL would the nurse give?

Given: Ordered dose of diphenhydramine: 25 mg Available diphenhydramine: 12.5 mg/5 mL Step 1: Set up the proportion: Desired dose (mg) / Volume to administer (mL) = Concentration (mg/mL) Step 2: Substitute the values: 25 mg / Volume = 12.5 mg/5 mL Step 3: Solve for the unknown volume: Volume = 25 mg / (12.5 mg/5 mL) Volume = 25 mg x (5 mL / 12.5 mg) Volume = 10 mL