Worked example

Oral dose - tablets - practice problem 3

The prescriber orders 850 mg of metformin PO. The pharmacy stocks metformin in 850 mg tablets.

Ordered dose850 mg

On hand850 mg per tablet

How many tablets should the nurse give?

Answer: 1 tablet

Step-by-step solution

1. Identify what you have and what you want

Have: 850 mg per tablet · Want: 850 mg

2. Set up dimensional analysis so mg cancels

850 mg × ( 1 tablet ÷ 850 mg )

3. Cancel mg and solve

= ( 850 × 1 ) ÷ 850 tablet

= 1 tablet