Worked example

Oral dose - tablets - practice problem 1

The prescriber orders 5 mg of lisinopril PO. The pharmacy stocks lisinopril in 2.5 mg tablets.

Ordered dose5 mg

On hand2.5 mg per tablet

How many tablets should the nurse give?

Answer: 2 tablets

Step-by-step solution

1. Identify what you have and what you want

Have: 2.5 mg per tablet · Want: 5 mg

2. Set up dimensional analysis so mg cancels

5 mg × ( 1 tablet ÷ 2.5 mg )

3. Cancel mg and solve

= ( 5 × 1 ) ÷ 2.5 tablet

= 2 tablets