Low-dose antibiotic prophylaxis lowers UTI incidence in clean intermittent self-catheterization users
Continuous low-dose antibiotic prophylaxis safely and effectively reduces the frequency of urinary tract infections (UTI) in adult users of clean intermittent self-catheterization (CISC), according to a recent study.
“The long-term implications of this intervention are uncertain, but increased pathogen resistance might make it more difficult to treat established infections in individuals, and increased resistance of bacteria that colonize urine and contribute to the faecal microbiome are a public health concern,” said researchers.
The trial included 404 community-dwelling CISC users who were randomized to receive either once-daily, low-dose antibiotic prophylaxis (n=203; mean age 59.1±17.0 years; 57 percent male) or no prophylaxis (controls; n=201; mean age 60.1 years; 57 percent male). [Lancet Infect Dis 2018;doi:10.1016/S1473-3099(18)30279-2]
Over the 12-month study period, symptomatic antibiotic-treated UTIs occurred at almost twice the rate in the no prophylaxis vs prophylaxis group (2.6 vs 1.3 cases per person-year; p<0.0001). The resulting incidence rate ratio (IRR) was 0.52 (95 percent CI, 0.44–0.61; p<0.0001), in favour of prophylaxis.
This was confirmed when the same analysis was performed on microbiologically confirmed UTIs. The corresponding incidence rates for the prophylaxis and nonprophylaxis participants were 0.74 and 1.5 cases per person-year (p<0.0001), resulting in an IRR similarly skewed towards prophylaxis (IRR, 0.49; 0.39–0.60; p<0.0001).
Antibiotic prophylaxis was also relatively safe, with only 9 percent (n=19) of the participants reporting 22 nonserious adverse events (AEs) related to medication. Thirteen changed agents or discontinued prophylaxis during the trial. The most common AEs were nausea, diarrhoea and candida infection.
In line with the benefits, participants who received antibiotic prophylaxis reported high degrees of treatment satisfaction, as measured by the Treatment Satisfaction Questionnaire for Medication (mean overall score 73.8±25.4).
However, in terms of health status, only small improvements were observed. Mental component scores were significantly better at the 6-month follow-up, but the difference was attenuated by month 12. Physical component scores did not significantly differ between groups both at 6 and 12 months.
Notably, urinary isolates from the prophylaxis vs nonprophylaxis group were more frequently resistant to eight oral antibiotics commonly used for UTIs. For instance, in samples submitted for testing between months 9 and 12, resistance to nitrofurantoin was more common in the prophylaxis group (24 percent vs 9 percent; p=0.038).
The same was true for resistance to trimethoprim (67 percent vs 33 percent; p=0.0003) and co-trimoxazole (53 percent vs 24 percent; p=0.002).
“Increased development of antimicrobial resistance over the 12-month trial duration in the prophylaxis group is a major concern that limits the appeal of the prophylaxis strategy,” said researchers, noting that while resistance was most pronounced against the drugs used in the present trial, it was also observed for other antibiotics commonly used in treating UTIs.
For the trial, participants randomized to receive antibiotic prophylaxis were given 50 mg nitrofurantoin, 100 mg trimethoprim or 250 mg cefalexin. Follow-ups were conducted over telephone or in person at 1, 3, 6, 9 and 12 months after randomization, during which participants were made to accomplish trial questionnaires and submit urine samples.
“Our data will help clinicians worldwide to provide more accurate information on the benefits and harms of antibiotic prophylaxis in this patient group,” said researchers.
“These data will aid more balanced decision making for CISC users who have repeated UTIs, considering the degree of individual patient distress and emerging threats from antimicrobial resistance,” they added.