LONDON, Canada. — Older women who are prescribed nitrofurantoin for urinary tract infections are more likely to experience treatment failure that results in a secondary antibiotic prescription or a hospital visit.
This discovery was studied to understand if nitrofurantoin is less effective in older women with low kidney function. It included about 10,000 women with low kidney function and 180,000 women with high kidney function.
In both groups nitrofurantoin was most likely to be ineffective when used against UTIs.
Findings were published in the April 17 edition of the journal CMAJ.
The study states that more than 25 percent of older adults have low kidney function, and bladder infections are common. Nitrofurantoin is prescribed for bladder infections, with an estimated 25 million prescriptions worldwide each year.
There is a concern that less of the drug actually reaches the urinary tract in patients with low kidney function, meaning it has problems working against the bacteria that cause bladder infections.
Researchers therefore recommend nitrofurantoin be avoided in people with low kidney function. Interestingly, though, the treatment failures were more likely when nitrofurantoin was used rather than ciprofloxin, regardless of the patient’s kidney function.
The researchers concluded that doctors should not avoid prescribing to women solely because they have low kidney function, but to take into account specific patterns of bacterial resistance before choosing a treatment.
Dr. Ren Bedell, ND, who practices Tempe, Ariz. said doctors take UTIs seriously.
“There is always a debate on which antibiotic works best for a UTI, as each doctor has there go to,” Bedell said. “This research confirms what has largely been a consensus, that nitrofurantoin has a very low renal penetration. In fact, nitrofurantoin is contraindicated in pyelonephritis for this reason.”
