Worked example

Oral dose - tablets - practice problem 12

The prescriber orders 2 mg of warfarin PO. The pharmacy stocks warfarin in 4 mg tablets.

Ordered dose2 mg

On hand4 mg per tablet

How many tablets should the nurse give?

Answer: 0.5 tablets

Step-by-step solution

1. Identify what you have and what you want

Have: 4 mg per tablet · Want: 2 mg

2. Set up dimensional analysis so mg cancels

2 mg × ( 1 tablet ÷ 4 mg )

3. Cancel mg and solve

= ( 2 × 1 ) ÷ 4 tablet

= 0.5 tablets