Can You Take Omeprazole And Trimethoprim Together?

In our latest question and answer, the pharmacist discusses whether or not there is a drug interaction between omeprazole and trimethoprim.


Hello, I currently take trimethoprim 300mg twice daily for my acne. I have recently been put on omeprazole 40mg to treat what is suspected silent reflux. Can these medications be taken together? as in the same day?

Asked by Lottie On Jun 22, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jun 24, 2022
Last updated Jun 24, 2022

Key points

  • There is no known drug interaction between omeprazole and trimethoprim. They can be taken the same day.

Thanks for reaching out to us!

We're always more than happy to help out.

First and foremost, there is no drug interaction between trimethoprim and omeprazole. They are considered safe when combined.

Now, even though certain drugs can have no reported interactions, that doesn't necessarily mean they can be taken at the same exact time, as many drugs have specific requirements for optimal absorption. So, let's take a look at each of these.

Omeprazole Administration

You mentioned you are taking omeprazole for 'silent reflux', which is also known as laryngopharyngeal reflux.

PPIs (proton pump inhibitors), like omeprazole, are the most commonly used drugs for this condition.

For best effect, omeprazole should be taken 30 minutes before breakfast (or dinner). This is because omeprazole only binds to, and inhibits, acid-producing cells when they are active.

Taking omeprazole 30 minutes before food ensures the drug is absorbed and ready to work prior to the acid-producing cells (parietal cells) becoming active.

Trimethoprim Administration

Trimethoprim is an antibiotic and is most commonly used in combination with another antibiotic, sulfamethoxazole, to treat a variety of bacterial infections.

Trimethoprim, as a single agent, is most commonly used to treat acne. It can be taken with or without food, and without regard to most other medications (as long as those medications don't interact with it).

Taking Together?

Based on what we know about the recommended administration for both omeprazole and trimethoprim, which I've written about in the section above,  it is safe to take them together, even at the same time, and certainly the same day.

Final Words

Thanks again for reaching out!

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About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication related questions!

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