Can You Take Amoxicillin And Metronidazole Together?

In our latest question and answer, the pharmacist discusses whether or not amoxicillin and metronidazole can be taken together.

Question

I was given amoxicillin and metronidazole to take together but I can't find anywhere if this combination is safe. Is it?

Asked by Bailey On Dec 06, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Dec 06, 2022
Last updated May 06, 2024

Key points

  • There is no interaction between amoxicillin and metronidazole and they are sometimes prescribed together.
  • Both amoxicillin and metronidazole can cause nausea and diarrhea, and these side effects might be more pronounced when taking both drugs. Taking them with food can help.

Answer

Yes, it is safe to take amoxicillin and metronidazole together. In fact, they are often prescribed together to treat certain conditions, such as H. Pylori (Helicobacter pylori) infections.

Combined Use

Both amoxicillin and metronidazole are antimicrobials, but work against different types of microbes, and have different mechanisms of action.

Amoxicillin is an aminopenicillin, a type of 'beta-lactam' antibiotic, and works by inhibiting bacterial cell wall synthesis by binding to specific penicillin-binding proteins (PBPs). It is considered a 'broad-spectrum' antibiotic as it covers both gram-positive and gram-negative bacteria, although plenty of bacteria are resistant to it.

Metronidazole on the other hand, is classified as both an antibacterial and antiprotozoal agent that belongs to a class known as nitroimidazoles. It covers mostly anaerobic bacteria as well as protozoa such as Trichomonas vaginalis, amebiasis, and giardiasis.

As mentioned, it's not uncommon that amoxicillin and metronidazole are combined.

You don't mention why you were prescribed these drugs, but I am guessing you either have (unluckily) multiple infections that need treatment, or you have an infection where both drugs are commonly used.

One such infection is an H. Pylori infection, a gram-negative bacteria that infects the stomach and intestines. Untreated, it can cause significant discomfort, gastric reflux and increase the risk of stomach ulcers.

A common treatment for H. Pylori is using a three or four-drug regimen that consists of several antibiotics and a proton pump inhibitor, like Prilosec.

Antibiotics such as amoxicillin, metronidazole, doxycycline, and clarithromycin are commonly used. 

Watch For Side Effects

Now, even though amoxicillin and metronidazole can safely be used together, they do share some common side effects, such as nausea and diarrhea.

It is possible that these side effects may be more pronounced when these drugs are taken together. Both drugs can be taken with food, and this may help decrease their severity.

If side effects become intolerable, be sure to speak with your doctor about them.

Final Words

Thanks for contacting us! I hope this answer helped.

References

  • Efficacy of omeprazole and amoxicillin with either clarithromycin or metronidazole on eradication of Helicobacter pylori in Chinese peptic ulcer patients, PubMed
  • Treatment of Helicobacter pylori Infection, JAMA
  • Metronidazole Monograph, PubChem
  • Amoxicillin Monograph, PubChem

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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