Is it safe to take omeprazole with a penicillin?

No interactions: Taking both omeprazole and penicillin is fine, there is no drug interaction between the two. It still may be best to take them separately to avoid stomach upset. It is also best to take both of these medications on an empty stomach. Take omeprazole at least 30 minutes before a meal. And even though you can take penicillin VK with food, it works better if you take it with an empty stomach.