Norfloxacin in the treatment of urinary tract infections in men with and without identifiable urologic complications

Predictors of admission in patients presenting to the emergency department with urinary tract infection

PURPOSE

Previous studies examining the management of urinary tract infections (UTI) showed marked variability in the economical burden of care, with a tenfold increase in costs when patients require admission to the hospital. We sought to examine the patient and emergency department (ED) characteristics associated with hospitalization in patients presenting to the ED with UTI.

METHODS

An estimate of 10,798,343 patients with a primary diagnosis of UTI was presented to the ED from 2006 to 2009 and was abstracted from the Nationwide Emergency Department Sample. Univariable and multivariable analyses examined patient and hospital characteristics of those admitted with UTI.

RESULTS

Between 2006 and 2009, 10.8 million patients presented to the ED in the United States for the treatment of UTI and 1.8 million patients (16.7 %) were admitted to the hospital for further management. Admitted patients were older, and a higher proportion had pyelonephritis, was male, and had Medicare. Admitted patients were also more likely to be seen at urban teaching hospitals, and/or treated at zip codes with higher median incomes. Following multivariable analysis, the independent predictors of admission included pyelonephritis (OR 5.29, 95 % CI 5.23-5.35), male gender (OR 1.58, 95 % CI 1.56-1.59), and advancing age (OR 1.037, 95 % CI 1.037-1.037).

CONCLUSIONS

Expansion in ED utilization for the management of UTI has exceeded previous estimates. While the preponderance of patients presenting to the ED for UTI is discharged home, 16.7 % are admitted for further management. Predictors of inpatient admission on multivariable analyses included pyelonephritis, advancing age, and male gender.

The quinolones. An overview of their pharmacology

The fluoroquinolones represent a relatively new class of antibiotics with outstanding therapeutic potential, attributable to their broad spectrum of antimicrobial activity and favourable tissue distribution. They are highly active against most Gram-negative pathogens, as well as Staphylococcus aureus and coagulase-negative staphylococci. In addition, the fluoroquinolones have useful pharmacokinetic properties: they are orally active, and their lipophilicity and low degree of plasma protein binding allow for excellent tissue penetration and concentrations, as reflected in their particularly large apparent volumes of distribution. Infections due to aerobic Gram-negative pathogens are considered those most susceptible to the quinolones. Disease indications in which these agents appear to offer the greatest therapeutic advantage over currently available alternatives include the following: complicated urinary tract infections (particularly those caused by Pseudomonas aeruginosa or resistant Gram-negative microorganisms); suspected bacterial gastroenteritis; eradication of Salmonella typhi from the faeces in known carriers; P. aeruginosa-associated respiratory exacerbation in patients with cystic fibrosis; and chronic Gram-negative bacterial osteomyelitis. Direct comparisons of the various quinolones are too limited to date to provide clear therapeutic options. Nevertheless, this class of compounds is likely to play a major role in providing effective oral therapy for conditions that have previously required prolonged parenteral treatment.

Fluoroquinolones in the treatment of typhoid fever and the carrier state

Typhoid fever remains an important public health problem throughout the world with a higher morbidity and mortality rate in the developing countries. Early establishment of the diagnosis and prompt initiation of treatment with chloramphenicol, ampicillin or trimethoprim-sulfamethoxazole is not necessarily followed by complete resolution of the infection. Between 1% and 6% of patients with typhoid fever become chronic biliary carriers of Salmonella typhi. These carriers are potential factors in the continued transmission of the disease. The increasing emergence worldwide of strains showing multiple resistance to the agents traditionally used in therapy has encouraged investigators to seek alternatives such as third generation cephalosporins and recently the new 4-quinolones, which have greater activity against Salmonella typhi including multi-resistant strains. The fluoroquinolones seem to be the treatment of choice in those regions where resistant strains of Salmonella typhi are prevalent.

Quinolone antimicrobial agents: adverse effects and bacterial resistance

Adverse effects, drug-drug interactions and bacterial resistance to the new quinolone antimicrobial agents are reviewed. Clinical adverse effects are reported to occur in 5-10% of patients, and include primarily gastrointestinal disturbances, central nervous system toxicity and rash. Laboratory abnormalities are reported to occur in 5-12% of patients, and include mild reversible elevations of transaminases. Quinolones are not recommended in persons whose bone growth is incomplete or in pregnant or nursing women because cartilage toxicity has been observed in juvenile beagles. Drug-drug interactions may occur between quinolones and theophylline, caffeine, and magnesium- or aluminium-containing compounds such as antacids and sucralfate. Bacterial resistance occurs by chromosomal mutations which alter the target enzyme DNA gyrase or decrease drug accumulation. Emergence of resistance during therapy is uncommon to date but can be problematic in infections with Pseudomonas aeruginosa. Staphylococcus aureus and other bacteria for which the therapeutic index may be low. In summary, quinolones thus far have been well tolerated, but more experience is needed to determine the exact nature and extent of adverse effects and emergence of bacterial resistance.