Final answer:
The nurse should inform the client that chlorpromazine should be taken on an empty stomach.
Step-by-step explanation:
When teaching a client with intractable hiccups about chlorpromazine, the nurse should include the information regarding taking the medication on an empty stomach. Taking chlorpromazine with food may decrease its absorption, leading to reduced effectiveness. Therefore, it is best to take chlorpromazine on an empty stomach to maximize its therapeutic effects.