> Compliance important in treating UUTIs
The article below is extracted from Medical Tribune dated 1 - 15 Oct 2005. You can download the issue from Medical Tribune website at http://www.medicaltribune.com/
Compliance important in treating UUTIs
Compliance to therapy is essential in keeping antibiotic resistance low in uncomplicated urinary tract infections, says an expert.
“Incomplete eradication of the bacteria due to non-compliance increases the possibility of development of bacterial strains that are resistant to the antibiotic,” said Associate Professor Dr. Chua Chong Beng, a consultant urologist from University of Malaya Medical Centre.
Uncomplicated urinary tract infections (UUTIs), which are common in young women, are often troublesome and bothersome. Patients often do not finish their course of antibiotics once their urinary symptoms are relieved. They might also switch to another antibiotic if rapid symptomatic relief is not obtained, said Chua in an interview with this newspaper.
Hence, ease of dosing, which increases compliance, should be considered when selecting an antibiotic for UUTI. Other selection factors include bacterial resistance and the ability to maintain urinary antibiotic levels above the mean inhibitory concentration (MIC) for an adequate period.
Current Malaysian guidelines recommend co-trimoxazole, trimethoprim, ampicillin or nitrofurantoin as the first-line antibiotic for UUTIs.
However, Chua commented that these guidelines are now outdated. Local data on antibiotic resistance is also not readily available. Nevertheless, studies in other countries have shown that the prevalence of resistance to these agents varies from 10 percent to 40 percent.
The WHO recommends that antibiotics with at least a 10% to 20% resistance rate should not be used as first-line empirical treatment.
According to Chua, many clinicians, including him, have moved away from using co-trimoxazole because of the increasing resistance. He said that he currently uses fosfomycin trometamol (Monurol®, Emerging Pharma) frequently in his clinical practice as this fulfilled all the criteria of a useful antibiotic in treating UUTIs.
The antibiotic, recently introduced in Malaysia, is available in a single-dose, orange-flavoured sachet equivalent to 3g fosfomycin. It has a long half-life and is present in the urine above the MIC for common bacterial causes of UUTIs for at least 48 hours.
The commonest organisms that cause UUTIs are E. Coli followed by K. Pneumonia and P.mirabilis.
Another advantage of fosfomycin is that, despite its widespread use since U.S. FDA approval in 1996, resistance rates have been reported to remain low.
A study in Genoa, Italy shoed that resistance to fosfomycin in the year 2000 was one percent compared to 1.7 percent for nitrofurantoin, 15 percent for norfloxacin and 24 percent for co-trimoxazole. [Int J Antimicrob Agents 2003:S79-83]
According to the manufacturer, fosfomycin is contraindicated in people who are hypersensitive to the drug and have severe renal insufficiency (creating clearance less than 10mL/min) and in patients undergoing hemodialysis.
Chua commented that based on his experience, hypersensitivity to fosfomycin was rare and all antibiotics should be used with caution in patients with impaired renal function.
Increasing resistance to co-trimoxazole has also resulted in increased use of fluroquinolones eg, norfloxacin and ciprofloxacin in treatments of UUTIs.
Nevertheless, Chua said the fluroquinolones were actually quite potent antibiotics that should be reserved for treating complicated UTIs. “In treating infectious diseases, you always want to have something stronger in reserve. You want to play your Jacks, Queens, and Kings first so that you still have your Ace,” he said.
Another useful antibiotic in treating UUTIs is nitrofurantoin. Nitrofurantoin is an older antibiotic that has not been used widely for a long time due to a high prevalence of resistance. Because of this decreased use for a prolonged period, resistance to this antibiotic has declined, hence making it a good antibiotic again for treating UUTIs currently.
