A nurse is teaching a client who has a duodenal ulcer about his new prescription for cimetidine. The nurse should include which of the following instructions in the teaching?

"You should plan to take this medication for at least 6 months."

"Your doctor might need to reduce your theophylline dose while taking this medication."

"Take the medication on an empty stomach for better absorption."

"Take the medication with an antacid to minimize stomach upset."