Is Amoxicillin Good for UTI?

Is Amoxicillin Good for UTI? – Overview

Many women and men experience a burning feeling when urinating or an annoying frequent or urgent need to go to the toilet. Once in a lifetime, every second woman will have an infection of the urinary tract. (1) If it happened to you so far, you know that antibiotics are the medications for curing bacterial infections.

Amoxicillin is one of the antibiotics that is practiced for the treatment of urinary and respiratory tract infections, and skin and genital organs for over four decades. (2) This long practice makes us confident about this safe and effective antibiotic. Much of this is true, however, today, certain bacteria show resistance to this antibiotic. So, when it comes to urinary tract infections (UTIs), the most common outpatient infections in the U.S., (1) the question is if Amoxicillin is good.

In this article, you can learn all about the symptoms and causes of UTIs. Keep reading to find out when Amoxicillin is appropriate and the latest recommendations for UTIs treatment and prevention.

How Do I Know If I Have UTI?

Urinary tract infections affect the bladder, urethra, ureters, or kidneys, the organs of the urinary system. Although UTIs affect men and women, in women UTIs are four times more frequent than in men. (3) Bacteria Escherichia Coli (E. Coli), which normally lives in the human gastrointestinal tract, is the reason for 65-75% of UTIs. (1)


You can recognize UTI symptoms, such as a burning feeling when you pee, a symptom that is associated with infection of the urethra (urethritis). You may also feel a frequent urge to pee, while after, unusually small quantities come out. Urinary infection can be followed by pain while peeing, urine color change to dark or bloody, cloudy, and with a strange smell. All these symptoms are associated with a bladder infection (cystitis). (3-5) In other cases, symptoms are not that specific for UTI.

Lower back pain on either side, fever, chills, nausea, and vomiting could be symptoms of kidney infection (pyelonephritis). This is why you shouldn’t underestimate symptoms and self-medicate; instead, visit the doctor and check if it is about UTI or not. (3-5)

Recurrent UTI

At least a fourth of the women who had UTI will have another infection within the next six months. (1) If UTIs are frequent, at least 3 times a year or two times in the last six months, then it is about recurrent UTIs. Estrogen deficiency and urinary retention are risks for recurrent UTIs in postmenopausal women. (6)


UTIs are treated with antibiotics, therefore you need a medical check and prescription. Be ready to give a urine sample at medical practice; the presence of bacteria or white blood cells in the urine sample can be a sign of infection. The healthcare provider will detect and identify the germ that caused the infection, a procedure that may take a couple of days. (7)

Not treated UTI can lead to recurrent UTI, kidney or blood infection that might require treatment in the hospital.

What is Amoxicillin?

Amoxicillin is a well-established penicillin-class antibiotic available in the U.S. since 1974, approved to treat infections of:

– ear, nose, and throat,

– genitourinary tract,

– skin and skin structure, and

– lower respiratory tract. (2)

The basis of amoxicillin is penicillin with an added amino group to its structure that improves penicillin resistance to antibiotics. (2) Amoxicillin has a broad spectrum which means that covers many bacteria such as Streptococcus species, Listeria Monocytogenes, Haemophilus Influenzae, Salmonella Spp, but also Escherichia Coli. (2)

Amoxicillin, as a ß-lactam antibiotic, disrupts the synthesis of the bacterial cell wall in a way that binds to specific proteins present on the inside of the bacterial cell wall. Once amoxicillin is bound, it disrupts the wall synthesis, which leads to bacterial lysis and death. (8)

How Effective is Amoxicillin Today Against E. Coli, the Leading Cause for UTIs?

In this fight between antibiotics and bacteria, certain bacteria species find a way to resist by producing the enzyme ß-lactamase. This enzyme inactivates ß-lactam antibiotics by hydrolyzing the ß-lactam ring in the antibiotic structure; as a result, bacteria become resistant to that drug. (8)

In the case of amoxicillin, clavulanic acid as potassium salt is added to amoxicillin-based drugs to protect amoxicillin from ß-lactamase inactivation. Clavulanic acid is a medication called beta-lactamase inhibitor that binds to ß-lactamase and inactivates the enzyme. This improved amoxicillin formulation became available for use in the U.S. ten years after amoxicillin was developed. (8-9)

Escherichia Coli Resistance

However, in the field of UTIs antibacterial therapy, amoxicillin efficiency has been reduced throughout the years. In 2001, results of a prospective study published in the Journal of Clinical Microbiology found a 20.3% resistance rate of E. Coli to amoxicillin among hospitalized patients. Previously published studies already suggested high resistant rates in a range of 25-40%. (10)

Five years later, the research of the North American Urinary Tract Infection Collaborative Alliance found that E.Coli is 37.7% resistant to ampicillin in outpatients from 40 medical centers in the U.S. and Canada. (11) Approximately 40% resistance rate of E.Coli to amoxicillin or ampicillin/beta-lactamase inhibitors was found among the Veterans Affairs patients. (12)

UTI Treatment Guidelines Recommendations

Increased resistance to amoxicillin and other ß-lactam antibiotics, reported in numerous studies, leads to treatment guidelines updates in a way that physicians can rely on the latest clinical evidence regarding antibiotic effectiveness in UTIs treatment.

The Infectious Diseases Society of America, in its 2010 guideline, recommends beta-lactamase agents when other recommended agents cannot be used for the treatment of acute uncomplicated cystitis. This guideline added:

“Amoxicillin and ampicillin should not be used for empirical treatment given the relatively poor efficacy and very high prevalence of antimicrobial resistance to these agents worldwide.” (13)

A year after, the Association of American Family Physicians (AAFP) published:

“Beta-lactam antibiotics, amoxicillin/clavulanate, cefaclor, cefdinir, and cefpodoxime are not recommended for initial treatment because of concerns about resistance.”

AAFP refers to guidelines that recommend other options for first-line treatment of acute uncomplicated cystitis: fosfomycin, nitrofurantoin, and trimethoprim/sulfamethoxazole. (14) These recommendations remain till today, where the latest guideline of the American Urology Association from 2022 recommends clinicians use these medications for first-line therapy for the treatment of symptomatic UTIs in women, depending on the local antibiogram. (15)

This resistance to amoxicillin is not only the case in the U.S. E.coli became resistant worldwide, therefore European Urology Association does not recommend:

“amoxicillin/clavulanic acid for empirical therapy due to ecological collateral damage, but may be used in selected cases”. (16)

Yet, amoxicillin is found as an effective treatment for UTI in young children and infants; therefore, the AAFP put amoxicillin and amoxicillin/clavulanate in the list of antibiotics commonly used to treat UTI in children. Yet, in the article from 2020, Dr. Brian Veauthier and Dr. Michael V. Miller clearly say that:

“Antibiotic selection should be based on local sensitivity patterns and adjusted once culture results are available.” (17)

Anyhow, antibacterial UTI treatment depends on the severity of the infection and the type of antibiotic and can take from 3 days up to 14 days if it is complicated. It is very important to take the full dose of the antibiotic your doctor prescribes, although you feel better after a few days. If you don’t take the full course, bacteria present in your urinary tract will not be killed and can become resistant to the antibiotic you take.

Other Useful Evidence-based Options

Numerous pieces of advice for the non-antibiotic treatment of UTI may be found on the internet today. Some of those are probably effective in prophylaxis, treatment, or symptom reduction, however, not all are clinically evidence-based. American Urology Association, according to the available studies, in its 2022 guideline suggests:

Cranberries – Cranberries have been studied in the form of juice, cocktail, or tablets. Different studies showed that cranberries can prevent UTIs, but also can prevent bacteria from sticking to the lining of the urinary tract, decrease the number of clinical UTI recurrences, and lower the risk of E Coli resistance;

Increased water intake – Women with recurrent uncomplicated UTIs can lower UTI episodes if they drink water >2L/day. This prophylactic effect was studied in women with recurrent UTIs who drink <1.5L or <0.9L water a day. Increased total intake to >2L water daily resulted in fewer episodes of UTIs;

Estrogen – Vaginal tablets, rings, or creams containing estrogen are recommended in peri- and post-menopausal women who experienced recurrent UTIs to reduce the risk of future UTIs. (15)
Other helpful preventive practices are urinating after sexual activity, showering instead of a bath, minimizing the use of sprays, or powders in the genital area, and wiping front to back as a regular practice in women. (4)

Final Thoughts

Painful cystitis, urgent pee, or other UTI is treatable with antibiotics and your doctor is the one who will tell you which one. Respectful healthcare associations recommend other first-line options, rather than amoxicillin for UTI treatment in adults. While E.Coli is highly resistant, amoxicillin is still effective against other bacteria and should be used accordingly for other bacterial infections.

When you feel symptoms, ask your doctor for advice. Untreated UTI may become recurrent or infection might spread to other organs and get complicated.

You can get antibiotic treatment only with a prescription. In case you experience any side effects described in the Medication Guide, inform your doctor. If it is serious, you or your doctor may send a report to the FDA MedWatch Adverse Event Reporting program.

Take antibiotics as long as prescribed and don’t discontinue earlier. Let antibiotics do their job and effectively fight bacteria; by this, you will maintain antibiotic effectiveness and not allow bacteria to become resistant.

See Also

Is Ibuprofen a Blood Thinner?

Do Blood Thinners Decrease Blood Pressure?

Do Blood Thinners Affect Oxygen Levels?

What is Creatinine Level in Blood Tests?

How to Educate Levels About High Blood Pressure?

Current Version
November 27, 2022
Written By
Biljana Srbinovska, MPharm
November 27, 2022
Medically Reviewed By
Franco Cuevas, MD

1. Medina M., Castillo-Pino E., An introduction to the epidemiology and burden of urinary tract infections, Therapeutic Advances in Urology, 2019 Jan-Dec; 11: 1756287219832172. Published online 2019 May 2. doi: 10.1177/1756287219832172, PMCID: PMC6502976, PMID: 31105774

2. Akhavan B.J., Khanna N.R., Vijhani P., Amoxicillin, Bookshelf ID: NBK482250PMID: 29489203,It%20is%20an%20amino-penicillin%2C%20created%20by%20adding%20an%20extra,negative%20coverage%20compared%20to%20penicillin

3. Urinary tract infections, MedlinePlus, August 8, 2016

4. Urinary tract infection, Centers for Disease Control and Prevention, October 6, 2021

5. Urinary tract infection, Mayo Clinic, September 14, 2022

6. James J. Arnold, DO, Laura E. Hehn, MD, and David A. Klein, MD, MPH, American Family Physician. 2016;93(7):560-569

7. Urinary tract infections in Adults, Urology Care Foundation, November 2022

8. Leah R. Uto; Valerie Gerriets, Clavulanic Acid, June 5, 2022

9. S.M.Drawz, and R.A.Bonomo, Three Decades of β-Lactamase Inhibitors, Clinical Microbiology Review, 2010 Jan; 23(1): 160–201. DOI: 10.1128/CMR.00037-09 PMCID: PMC2806661 PMID: 20065329

10. A.Sotto at all, Risk Factors for Antibiotic-Resistant Escherichia coli Isolated from Hospitalized Patients with Urinary Tract Infections: a Prospective Study, Journal of Clinical Microbiology Volume 39, Issue 2, 1 February 2001, Pages 438-444

11. G.G.Zhanel et al., Antibiotic resistance in Escherichia coli outpatient urinary isolates: final results from the North American Urinary Tract Infection Collaborative Alliance (NAUTICA), International Journal of Antimicrobial Agents, Volume 27, Issue 6, June 2006, Pages 468-475

12. H.J.Morrill, Antimicrobial Resistance of Escherichia coli Urinary Isolates in the Veterans Affairs Health Care System, American Society for Microbiology, Antimicrobial Agents and Chemotherapy Volume 61, Issue 5, May 2017,

13. K.Gupta et al., International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases, March 1, 2011

14. R.Colgan MD and M.Williams, MD, Diagnosis and Treatment of Acute Uncomplicated Cystitis, American Family Physician, October 1, 2011

15. Recurrent Uncomplicated Urinary Tract Infections in Women: American Urological Association/Canadian Urological Association/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction Guideline, 2022

16. European Urology Association Guidelines on Urological Infections, March 2022

17. B.Veathier, MD, and M.V.Miller DO, Urinary Tract Infections in Young Children and Infants: Common Questions and Answers, American Family Physician, September 1, 2020


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