Does Nitrofurantoin Contain Penicillin?

Nitrofurantoin is an antibiotic prescribed to treat UTIs. Since penicillin can also treat UTIs, it’s natural for those with a penicillin allergy to wonder if nitrofurantoin contains penicillin, but it does not. Furthermore, nitrofurantoin is safe for those with a penicillin allergy.

Continue reading to learn more about nitrofurantoin and what antibiotics to avoid if you have a penicillin allergy. 

Key Takeaways:

  • Nitrofurantoin is an antibiotic prescribed for lower UTIs.
  • Nitrofurantoin does not contain penicillin and is safe for those with a penicillin allergy.
  • Some people should not take nitrofurantoin––always check with your doctor beforehand.

Table of Contents

What Is Nitrofurantoin?

Nitrofurantoin is an antibiotic prescribed to treat bacterial infections, particularly urinary tract infections because it collects in the urinary tract. It is effective against both gram-positive and gram-negative bacteria, which is a distinction referring to their cell walls. 

Nitrofurantoin is only available as an oral antibiotic and goes by the brand names Macrobid, Macrodantin, or Nitro Macro. It belongs to the nitrofuran class of antibiotics, meaning it is safe for those with penicillin or sulfa allergies. 

A benefit of nitrofurantoin is that it concentrates in the lower urinary tract and does not significantly affect bowel flora, meaning its side effects, specifically those involving the stomach, may be less severe. 

Nitrofurantoin treats bacterial infections by inhibiting the bacteria’s production of enzymes needed to synthesize DNA, RNA, and cell wall proteins. Because of this very broad mechanism of action, bacterial resistance to nitrofurantoin is uncommon. 

Side Effects

Some of the common side effects of nitrofurantoin include:

  • mild diarrhea
  • gas
  • headache
  • vaginal itching or discharge
  • dizziness

However, some more severe side effects may also develop, with older adults and those who are ill at a higher risk. Contact your doctor immediately if you experience any of the following:

  • sudden chest pain or discomfort
  • bloody or watery diarrhea
  • wheezing
  • fever
  • body aches
  • new or worsening cough
  • difficulty breathing
  • tingling, numbness, or pain in the hands or feet
  • lupus-like syndrome (swollen glands, joint pain or swelling accompanied by fever, chest pain, muscle aches, unusual thoughts or behaviors, vomiting, patchy skin color)
  • liver problems (upper stomach pain, nausea, loss of appetite, itching, clay-colors stools, dark urine, yellowing of the eyes or skin)

Even though nitrofurantoin does not contain penicillin, and is thus safe for those with a penicillin allergy, some people may be allergic to it. These symptoms include difficulty breathing, hives, and swelling of the throat, face, tongue, or lips. Seek immediate medical attention if you experience any of these symptoms. 

List of Antibiotics That Contain Penicillin

Penicillin involves a class of antibiotics, and it includes the following antibiotics:

  • penicillin G
  • nafcillin
  • amoxicillin
  • oxacillin
  • flucloxacillin
  • ampicillin
  • dicloxacillin
  • ticarcillin
  • carbenicillin
  • piperacillin

Some of these penicillins may also be combined with a beta-lactamase inhibitor to increase the effectiveness of the antibiotic. Some of these combinations include Augmentin (amoxicillin/potassium clavulanate), Zosyn (piperacillin/tazobactam), and ampicillin/sulbactam. 

If you have a penicillin allergy and are unsure if a prescribed antibiotic contains penicillin, check with your doctor. 

Who Can (And Who Can’t) Take Nitrofurantoin?

In general, those who take nitrofurantoin should only be individuals with a lower and uncomplicated UTI. 

Those who shouldn’t take nitrofurantoin include those with severe kidney disease, a history of jaundice or liver problems (especially those caused by nitrofurantoin), and difficulty urinating. Additionally, women in the last 2-4 weeks of their pregnancy should not take nitrofurantoin, and since nitrofurantoin can pass into breast milk, it is not recommended to breastfeed while taking nitrofurantoin. 

In order to ensure nitrofurantoin is safe for you, be sure to tell your doctor if you have any of the following:

  • anemia
  • kidney disease
  • diabetes
  • glucose-6-phosphate dehydrogenase (G6PD) deficiency
  • vitamin B deficiency
  • an electrolyte imbalance
  • any debilitating disease

In Conclusion

Nitrofurantoin is an antibiotic prescribed to treat lower UTIs. It belongs to the nitrofuran class of antibiotics and does not contain penicillin, making it safe for those with a penicillin allergy.

Still, this antibiotic may not be safe for everyone, with pregnant/breastfeeding women and those with liver problems or kidney disease not recommended to take this antibiotic. However, your doctor can help you determine the safety of nitrofurantoin for your situation. 

Key Takeaways:

  • Nitrofurantoin is an antibiotic prescribed for lower UTIs.
  • Nitrofurantoin does not contain penicillin and is safe for those with a penicillin allergy.
  • Some people should not take nitrofurantoin––always check with your doctor beforehand.


  • Squadrito FJ, del Portal D. Nitrofurantoin. [Updated 2023 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: 
  • McGarry, M. R., Wagner, M. W., & Wall, B. M. (2021). Systemic Inflammatory Response Syndrome Secondary to Nitrofurantoin. Journal of investigative medicine high impact case reports, 9, 2324709620984610. 
  • Malik, R. D., Wu, Y. R., Christie, A. L., Alhalabi, F., & Zimmern, P. E. (2018). Impact of Allergy and Resistance on Antibiotic Selection for Recurrent Urinary Tract Infections in Older Women. Urology, 113, 26–33. 
  • van Driel, A. A., Muller, A. E., Wijma, R. A., Stobberingh, E. E., Verbon, A., & Koch, B. C. (2023). European Journal of Clinical Pharmacology, 79(8), 1043–1049. doi: 
  • Claussen, K., Stocks, E., Bhat, D., Fish, J., & Rubin, C. D. (2017). Journal of the American Geriatrics Society, 65(6), 1316–1320. doi: 

Content on the DrHouse website is written by our medical content team and reviewed by qualified MDs, PhDs, NPs, and PharmDs. We follow strict content creation guidelines to ensure accurate medical information. However, this content is for informational purposes only and not a substitute for professional medical advice, diagnosis, or treatment. For more information read our medical disclaimer.

Always consult with your physician or other qualified health providers about medical concerns. Never disregard professional medical advice or delay seeking it based on what you read on this website.

If you are experiencing high fever (>103F/39.4C), shortness of breath, difficulty breathing, chest pain, heart palpitations, abnormal bruising, abnormal bleeding, extreme fatigue, dizziness, new weakness or paralysis, difficulty with speech, confusion, extreme pain in any body part, or inability to remain hydrated or keep down fluids or feel you may have any other life-threatening condition, please go to the emergency department or call 911 immediately.



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