Doctors sound alarm as over-the-counter drug taken by millions is linked to CANCER

Daily Mail​

27-05-2025

A common medication taken by more than 100 million worldwide for urinary tract infections has been linked to cancer.
Phenazopyridine, which is sold under various brand names including Azo, Pyridium, Prodium, Pyridiate, Baridium, and Uricalm, is available over the counter (OTC) in the US at lower strengths and by prescription at higher strengths.
It works by numbing the lining of the urinary tract, which helps to lessen the symptoms of urinary tract infections (UTIs), which include burning, irritation, and discomfort, as well as frequent and urgent urination.
But now experts are warning that phenazopyridine could cause cancer based on evidence from animal studies.
In one study conducted by the NIH, it was found that dietary exposure to phenazopyridine caused tumors in two rodent species at two different tissue sites.
In female mice, it caused benign and malignant liver tumors while in rats of both sexes, it caused benign or malignant colorectal tumors.
The government agency noted that while the animal studies don't prove a direct link between human cancer and exposure to phenazopyridine, it is 'reasonably anticipated to be a human carcinogen'.
Experts say these findings are troubling, especially as phenazopyridine doesn't require a prescription in the US as it does in many other parts of the world, including the UK and Canada.
Some of the reported side effects of the medication, as highlighted by the Mayo Clinic, include chest tightness, dizziness, lethargy, loss of appetite and stomach pain.
Meanwhile, some of the more severe adverse reactions have been known to include depression, muscle twitching, kidney failure, seizures and nose bleeds.
Rita Jew, who serves as the president of the Institute for Safe Medication Practices, says that personally she would not advise taking phenazopyridine.
She told Bloomberg: 'There is no need for this drug.'
Remedies containing a mix of methenamine and sodium salicylate are seen as an alternative to phenazopyridine.
Similarly, they help treat the pain and discomfort caused by UTIs until antibiotics can be prescribed and collected.
Antibiotics are the primary cure for UTIs as they target and eliminate the bacteria causing the infection. The most common antibiotics recommended for treatment are nitrofurantoin, trimethoprim/sulfamethoxazole, and fosfomycin.
In the US, UTIs result in approximately 10.5 million office visits as well as 3 million emergency department encounters and 400,000 hospitalizations annually.
While many people turn to phenazopyridine for temporary pain relief, the exact number of sales is not known as it is sold under different brand names.
New York-based gynecologist Steven Goldstein, who recommends the medication to patients while they are awaiting the results of urine tests, said he was totally unaware of the cancer links.
'It's the first time I'm even hearing about this. I'm totally unaware.' he told Bloomberg.
The NIH warning was published in 2021, while the National Cancer Institute study it refers to was carried out in 1978.
UTIs occur when bacteria enters the urinary tract through the urethra, the tube that filters urine out of the bladder.
Women are most at risk due to having a shorter urethra than men.
This means bacteria has less distance to travel to reach the bladder.
Roughly half of US women are expected to have at least one UTI in their lifetime compared to one in 20 men.
Sex can also increase the risk by pushing bacteria toward the urethra.
However, science is also beginning to point toward E coli from food as a potential cause.
A 2023 study from George Washington University, for example, analyzed retail samples of chicken, turkey, and pork and then took blood and urine samples from people hospitalized with UTIs.
The team found between 480,000 and 680,000 cases - about eight percent - could be caused by E coli strains found in the meat.
Recent reports also suggest meat consumption is on the rise, which could explain the increase in UTIs.