Treatment duration for urinary tract infections in adults

Adverse events after outpatient colonoscopy in the Medicare population

BACKGROUND

Although use of colonoscopy has increased substantially among elderly Medicare beneficiaries, no one has described colonoscopy-related adverse events in a representative sample of Medicare patients.

OBJECTIVE

To determine risk for adverse events after outpatient colonoscopy in elderly patients.

DESIGN

Population-based, matched cohort study.

SETTING

Surveillance, Epidemiology, and End Results cancer registry areas.

PATIENTS

Random 5% sample of Medicare beneficiaries, age 66 to 95 years, who underwent outpatient colonoscopy between 1 July 2001 and 31 October 2005 (n = 53 220), matched with beneficiaries who did not have colonoscopy.

MEASUREMENTS

Medicare claims were used to measure the rate of serious gastrointestinal events (bleeding and perforation), other gastrointestinal events, and cardiovascular events resulting in a hospitalization or emergency department visit within 30 days after colonoscopy compared with matched beneficiaries who did not have colonoscopy. Logistic regression was used to estimate adjusted predictive risks for adverse events and to assess whether these events varied by age, comorbid conditions, or type of colonoscopy.

RESULTS

Persons undergoing colonoscopy had a higher risk for adverse gastrointestinal events than their matched group. Rates of adverse events after colonoscopy increased with age. Patients having polypectomy had higher risk for all adverse events compared with their matched group and with the screening and diagnostic colonoscopy groups. Comorbid conditions increased the risk for adverse events. Patients with a history of stroke, chronic obstructive pulmonary disease, atrial fibrillation, or congestive heart failure had significantly higher risk for serious gastrointestinal events.

LIMITATION

The analysis relied on the diagnosis and procedure codes recorded on the Medicare claims.

CONCLUSION

Risks for adverse events after outpatient colonoscopy among elderly Medicare beneficiaries were low; however, they increased with age with specific comorbid conditions and depending on whether polypectomy was done. These data may inform decisions on whether to perform colonoscopy in persons of advanced age or those with comorbid conditions.

Gatifloxacin 400mg as a single shot or 200mg once daily for 3 days is as effective as ciprofloxacin 250mg twice daily for the treatment of patients with uncomplicated urinary tract infections

The efficacy and safety of two oral dosing regimens of gatifloxacin compared with ciprofloxacin for the treatment of acute uncomplicated lower urinary tract infection was investigated in a double-blind, randomised study, in adult female patients who received either gatifloxacin (400 mg as a single shot or 3 days of 200 mg once daily) or ciprofloxacin (250 mg given twice daily for 3 days). Bacteriological and clinical responses were assessed 7-9 days after the end of treatment (EOT), and 4-6 weeks post-treatment (end of study, EOS). One thousand one hundred and two women were treated, 741 (248 in the gatifloxacin 400 mg group, 252 in the gatifloxacin 200 mg group, and 241 in the ciprofloxacin group) presented with bacteriological proof of infection and entered the efficacy analysis. The bacteriological response per patient at EOT in the three groups were 80% (177/220) [95% CI to ciprofloxacin -8.4%; 6.4%], 83% (184/222) [95% CI to ciprofloxacin -5.9%; 8.7%] and 81% (176/216), respectively. At the follow-up assessment they were slightly lower, 75% (167/224), 79% (169/213) and 79% (171/217), respectively. The clinical responses at EOT were 81% (197/243) [95% CI to ciprofloxacin -10.2%; 3.4%], 85% (213/250) [95% CI to ciprofloxacin -5.7%; 7.2%] and 85% (201/238), respectively. At EOS they were 82% (195/239), 88% (212/241) and 86% (200/233), respectively. The eradication rates for all initial pathogens at the EOT were 90.3% in the gatifloxacin 400 mg S.D. group, 90.6% in the gatifloxacin 200 mg group, and 88.3% in the ciprofloxacin group. All treatment groups showed a similar safety profile. The incidence of treatment-related adverse events was comparable, the majority of adverse events were of mild or moderate intensity and the medications were well tolerated. Both the administration of gatifloxacin 200 mg once daily for 3 days, and gatifloxacin 400 mg as a single shot were shown to be equivalent to ciprofloxacin 250 mg twice daily for 3 days for the treatment of acute uncomplicated lower urinary tract infections.

Pharmacologic Basis for the Treatment of Pyelonephritis

Urinary tract infections (UTIs) are among the most common bacterial infections in humans. Even though physicians have been treating UTIs for 60 years, there has been no standardized approach regarding the rational choice of antimicrobial agents and optimal treatment duration for these infections. This review discusses the pharmacologic basis for the treatment of UTIs. Although most antibiotics concentrate well in the urine and can eradicate most of the sensitive uropathogens that cause lower UTI, antibiotics given for the treatment of pyelonephritis must concentrate and kill bacteria embedded within the renal parenchyma. Investigators once believed that antibiotics must concentrate in sufficient amounts in the urine of infected patients to be effective in treating pyelonephritis. In fact, the efficacy of an antibiotic in the treatment of pyelonephritis is proportional to its capacity to converge in high concentration not only in urine but also in the renal parenchyma because serum and urine levels of antibiotics are poor predictors of the intrarenal levels. Other factors should also be taken into consideration in the management of UTIs, such as the time of day antibiotics are given because significant time-dependent differences have been observed in the pharmacokinetics and rate of excretion in urine of several antibiotics. Finally, the authors review the recent development in the inflammatory response in the urinary tract that may explain the clinical features of UTI and may be useful in the diagnosis as well as better management of UTI.

Hospital-acquired infection in elderly patients

Increasing numbers of elderly people are being treated in hospitals and are at particular risk of acquiring infections. The incidence, risk factors and types of hospital-acquired infection (HAI) in the elderly are reviewed. Special reference is made to urinary tract infections, respiratory tract infections, gastrointestinal infections including Clostridium difficile, bacteraemia, skin and soft tissue infections and infections with antibiotic-resistant organisms.

Bacteremia in young urban women admitted with pyelonephritis

The objective of this study was to determine the rate of bacteremia in young women admitted to the hospital with presumed pyelonephritis and compare it with other published rates. The study design was a retrospective, structured chart review and a review of published reports of bacteremic pyelonephritis. An urban county teaching hospital provided the setting for the study. The patients were nonpregnant women (n = 98) 44 years of age or younger who were without bladder dysfunction and who had not been admitted to an intensive care unit. Further criteria for participation included discharge with the diagnosis of acute pyelonephritis. Blood cultures were ordered for 69 women; the results of 64 were noted in the chart. Twenty-three women (35.9% of those cultured; 23.4% of all patients) were diagnosed with bacteremia. In patients for whom blood culture results were obtained, trends developed between those patients with bacteremia and those with complicated pyelonephritis, defined as a known or newly discovered genitourinary abnormality or a risk factor (P = 0.044), those who were black (P = .044), those with higher pulses on admission (P = .050), those with more white blood cells per high-powered field after urinalysis (P = 0.007), and those whose fever lasted longer (P = 0.033). Blood culture results were positive in two patients whose urine cultures were negative. This comparatively high bacteremia rate supports routine ordering of blood cultures for urban women suspected of having pyelonephritis.

Does treatment of asymptomatic bacteriuria in older ambulatory women reduce subsequent symptoms of urinary tract infection?

OBJECTIVE

To determine whether treatment of symptomatic bacteriuria in older ambulatory women affects the subsequent development of symptoms of urinary tract infection.

DESIGN

A controlled clinical trial.

PARTICIPANTS

Older women not having urinary catheters.

MEASUREMENTS

Urine cultures every 6 months (the same organism at 10(5) colony-forming units or more per mL on two midstream urine specimens defined asymptomatic bacteriuria) and questionnaire surveys for the new development of symptoms of urinary tract infection (dysuria, frequency, urgency, low back pain with fever) 1, 3, and 6 months after the initial survey.

RESULTS

Of the 23 initially culture-positive participants receiving antibiotic treatment for symptomatic bacteriuria, nine were culture positive at 6 months, which contrasts with 18 of 27 who received no treatment or placebo, P = .05. However, symptoms of urinary tract infection were more common in the antibiotic-treated group.

CONCLUSION

Antibiotic therapy effectively reduced the subsequent occurrence of positive urine cultures, but symptoms were not reduced. Based on this study of morbidity, previous studies failing to show any relation to mortality, and the cost and complications of antibiotic therapy in the older population, treatment of asymptomatic bacteriuria in older women is contraindicated.

Treatment of pyelonephritis in adults

Although prescribing an antibiotic for the treatment of pyelonephritis seems to be a relatively easy task, a close look at the available data is disturbing. Optimal therapies for the different clinical syndromes of pyelonephritis have not yet been defined. The high failure rate suggests that in pyelonephritis (bacteria protected in the medulla) as well as in bacterial endocarditis (bacteria sequestered in vegetations) and in infections in neutropenic patients (host defenses not necessarily operating in conjunction with antibiotics), it may be necessary to maintain bactericidal levels at the site of infection (infected medulla) to achieve cure. Pharmacodynamic studies suggest that TMP/SMX, quinolones, and aminoglycosides, which penetrate well the infected renal parenchyma and are not impaired by the local inflammatory process, should, with the exception of pyelonephritis in pregnancy, be preferred to beta-lactams as first-choice agents for the therapy of gram-negative pyelonephritis.

Identifying and treating common and uncommon infections in the patient with diabetes

Patients with diabetes represent a unique group of individuals who appear more prone than others to developing infections. Several mechanisms have been proposed to explain the association between diabetes and infections. However, few conclusive studies exist and considerable debate continues regarding evidence for this predisposition. Despite this lack of documented proof, many health care practitioners acknowledge that a number of infections are overrepresented in patients with diabetes. Some of these infections appear to occur exclusively in patients with diabetes, especially patients who are poorly controlled. The presenting clinical features, causative organisms, and preferred treatment approaches will be discussed in this article for a variety of common and uncommon infections observed in patients with diabetes. In addition, the proposed predisposing factors will be addressed briefly.

Enoxacin relieves symptoms of recurrent urinary infections more rapidly than cefuroxime axetil

In patients with a history of recurrent infections, treatment with enoxacin (200 mg/12 h for 3 days) relieved symptoms of acute urinary infection significantly more rapidly than treatment with cefuroxime axetil (125 mg/12 h for 7 days). Other parameters, including clinical and bacteriological cure rates and patients' overall opinion of their treatment, did not differ significantly between the treatments.

Acute urinary tract infection in women. What kind of antibiotic therapy is optimal?

Urinary tract infections continue to be a major health problem for women. Understanding of the pathogenesis of urinary tract infections has improved; Staphylococcus saprophyticus has been recognized as a common causative agent, and low-colony-count infections are misdiagnosed less often. Traditional therapy with 10 days of amoxicillin (Amoxil, Wymox) or ampicillin (Omnipen, Totacillin) is no longer considered optimal. For women who fulfill certain clinical criteria, short-course therapy is recommended--preferably 3 days of trimethoprim-sulfamethoxazole, or trimethoprim alone (Proloprim, Trimpex) if the woman is allergic to sulfonamides. Longer therapy is indicated for women with complicated, prolonged, or recurrent infections. To appropriately treat patients and avoid overtreatment that would increase both costs and the incidence of side effects, physicians need to stay abreast of information about pathogens, mechanisms of disease, new drugs, and common resistance patterns.

Diagnosis and drug treatment of acute pyelonephritis

The term pyelonephritis, which denotes infection of the renal pelvis and of the renal tissue, covers a spectrum of entities, the gravity and hence treatment of which depend upon the organism, its sensitivity to antibiotics, the presence or absence of urinary tract obstruction, and the host's background. The common form affects young females, is due to uropathogenic but multisensitive strains of Escherichia coli, and is easily treated by a 10- to 20-day course of antibiotic(s). In males, children and immunocompromised patients, renal and urinary tract imaging is necessary to determine the cause of the infection, the severity of the lesions and thus to guide the duration of treatment, which comprises antibiotic combinations for several weeks. Pyelonephritis during pregnancy may be serious, and treatment is restricted to certain antibiotics. Aminoglycosides, amino- or carboxypenicillins (alone or associated with clavulanic acid), ureidopenicillins (e.g. mezlocillin, piperacillin), fluoroquinolones (e.g. ciprofloxacin, ofloxacin, pefloxacin), cephalosporins, monobactams (e.g. aztreonam), carbapenems (e.g. imipenem) and the combination of trimethoprim plus a sulphonamide [e.g. cotrimoxazole (trimethoprim/sulfamethoxazole)] offer a wide choice of bactericidal agents which may be used for the treatment of pyelonephritis. However, the selection among them also depends on availability, antimicrobial spectrum, tolerance and cost.

Use of ciprofloxacin versus use of aminoglycosides for therapy of complicated urinary tract infection: prospective, randomized clinical and pharmacokinetic study

The efficacy of oral ciprofloxacin was compared with that of parenteral aminoglycoside for therapy of complicated urinary tract infection in a prospective randomized trial. The setting was a chronic-care Veterans Administration facility in which long-term bladder catheterization and resistant bacteria were common. Sixty-five consecutive patients were stratified for presence and type of bladder catheter, the presence of Providencia and Pseudomonas aeruginosa organisms versus other urinary pathogens, and renal dysfunction. A pharmacokinetic study of ciprofloxacin concentrations in serum and urine was performed with selected patients. Urinary catheters were present in 94%. All patients were symptomatic, and 58.5% had fever. Ciprofloxacin, 500 mg every 12 h orally, was compared with parenteral aminoglycoside for 7 to 10 days. Clinical response, defined by resolution of symptoms and fever at 5 to 9 days posttherapy (short-term) and 28 to 30 days posttherapy (long-term), was essentially identical for both treatment groups. Bacteriologic response, defined by sterile urine cultures, showed that ciprofloxacin was significantly more efficacious (P = 0.0005) than aminoglycoside at 5 to 9 days posttherapy. However, by 28 to 30 days, the response rate was essentially identical. Emergence of resistance to the study antibiotic was seen in 62 and 70% of those who did not show a bacteriological response and were receiving ciprofloxacin and aminoglycosides, respectively. Concentrations of ciprofloxacin and aminoglycoside in the urine substantially exceeded the MIC for the urinary pathogens isolated, although these concentrations did not correlate with short-term bacteriologic response for either antibiotic. Ciprofloxacin was efficacious in complicated urinary tract infection compared with the current standard of parenteral aminoglycoside among catheterized patients with relatively resistant bacteria.

Predicting fraction dose absorbed in humans using a macroscopic mass balance approach

A theoretical approach for estimating fraction dose absorbed in humans has been developed based on a macroscopic mass balance that incorporates membrane permeability and solubility considerations. The macroscopic mass balance approach (MMBA) is a flow model approach that utilizes fundamental mass transfer theory for estimating the extent of absorption for passively as well as nonpassively absorbed drugs. The mass balance on a tube with steady input and a wall flux of Jw = PwCb results in the following expression for fraction dose absorbed, F: [formula; see text] where the absorption number, An = L/R.Pw/(vz), L and R are the intestinal length and radius, Pw is the unbiased drug wall permeability, (vz) is the axial fluid velocity, C*b = Cb/Co and is the dimensionless bulk or lumen drug concentration, Cb and Co are the bulk and initial drug concentrations, respectively, and z* is the fractional intestinal length and is equal to z/L. Three theoretical cases are considered: (I) Co less than or equal to S, Cm less than or equal to S, (II) Co greater than S, Cm less than or equal to S, and (III) Co greater than S, Cm greater than S, where S is the drug solubility and Cm is the outlet drug concentration. Solving the general steady-state mass balance result for fraction dose absorbed using the mixing tank (MT) and complete radial mixing (CRM) models results in the expressions for the fraction dose absorbed in humans. Two previously published empirical correlations for estimating fraction dose absorbed in humans are discussed and shown to follow as special cases of this theoretical approach. The MMBA is also applied to amoxicillin, a commonly prescribed orally absorbed beta-lactam antibiotic for several doses. The parameters used in the correlation were determined from in situ or in vitro experiments along with a calculated system scaling parameter. The fraction dose absorbed calculated using the MMBA is compared to human amoxicillin pharmacokinetic results from the literature with initial doses approximated to be both above and below its solubility. The results of the MMBA correlation are discussed with respect to the nonpassive absorption mechanism and solubility limitation of amoxicillin. The MMBA is shown to be a fundamental, theoretically based model for estimating fraction dose absorbed in humans from in situ and in vitro parameters from which previously published empirical correlations follow as special cases.

A randomized, dose comparison study of cefodizime in the treatment of lower urinary tract infections in women

In a prospective randomized study, the efficacy and safety of 1 and 2 g of cefodizime administered as single intramuscular injections were compared in a total of 50 women having either complicated or uncomplicated lower urinary tract infections (LUTI). Bacteriological culture of urine and safety laboratory tests were performed before and after treatment. 18/25 patients in the 1 g cefodizime group and 22/25 in the 2 g cefodizime group showed satisfactory clinical and bacteriological response to treatment. The inadequately treated patients all had complicating factors on entry to the study (residual urine in six cases, a bladder malignancy in two, neurogenic bladder and diabetes mellitus with glucosuria in one case each). Cefodizime proved efficacious in female patients with uncomplicated LUTI, as well as in those aged over 65 years, patients having mild renal insufficiency, mild glucosuria, unsuccessful oral antibiotic pretreatment or recurrent and postoperative infections. In no case were there any systemic adverse reactions to cefodizime or clinically significant changes in laboratory tests.

Single dose oral administration of cefixime 400mg in the treatment of acute uncomplicated cystitis and gonorrhoea

A placebo-controlled prospective randomised double-blind study was performed in 80 consecutive female outpatients with acute cystitis. Single dose oral antibiotic treatment was successful in 89.4% of patients treated with cefixime 400mg or ofloxacin 200mg and in 84.2% of those receiving cotrimoxazole (160/800mg). Bacteriuria was eradicated in 26.3% of patients in the placebo group. Two noncomparative clinical trials involving a total of 43 male patients with acute gonococcal urethritis reported a 100% cure rate after administration of a single 400mg dose of cefixime. Such single dose regimens offer the advantages of reduced expense, good tolerability, minimal alteration of normal bacterial flora, and the potential for improved patient compliance, compared with multiple dose antibacterial therapy.

Review of published studies on single dose therapy of urinary tract infections

The published studies of the use of single dose antimicrobial therapy for the treatment of urinary tract infection have been reviewed. In women and children a single dose of any of several antimicrobial agents was as effective as a course of treatment for uncomplicated urinary tract infections caused by Escherichia coli. Trimethoprim or co-trimoxazole are currently the preferred agents for single dose therapy. Failure of single dose therapy may prove to be a simple guide as to the need for further urinary tract investigation or more intensive therapy. Single dose antimicrobial therapy is now the treatment of choice for uncomplicated urinary tract infections.

The optimal management of lower urinary tract infections

Lower urinary tract infection is a common problem for women, and tends to be recurrent. It is not associated with significant long term morbidity. Optimal management for symptomatic infection is short course antimicrobial therapy. For women with frequent, symptomatic, recurrent infection a number of therapeutic options are available including single dose self-treatment, extended low dose prophylaxis, or post-intercourse prophylaxis. For women who do not wish to experience any symptomatic episodes, prophylactic therapy, either continuous or during risk situations particularly post-intercourse, are other options. Which therapeutic strategy is followed should be based on patient preference.

Different lengths of treatment with co-trimoxazole for acute uncomplicated urinary tract infections in women

STUDY OBJECTIVE

To compare three days' and seven days' treatment with co-trimoxazole in women with acute dysuria, strangury, and urinary frequency or urgency.

DESIGN

Randomised double blind placebo controlled trial.

SETTING

General practices in the south east of The Netherlands.

PATIENTS

327 Non-pregnant female patients aged 12 to 65.

INTERVENTION

161 Women were allocated to three days' treatment (co-trimoxazole 960 mg twice a day), and 166 women were allocated to seven days' treatment (co-trimoxazole 960 mg twice a day).

MAIN OUTCOME MEASURE

Resolution of symptoms at one, two, and six weeks.

RESULTS

The rates for resolution of symptoms were not significantly different between the two groups. Cumulative rates of recurrence after three days' and seven days' treatment were 31/139 (22%) and 23/151 (15%) respectively six weeks after entry (p = 0.16). Adverse effects occurred in a quarter of women given three days' treatment compared with a third of women receiving seven days' treatment (p = 0.29). In only two patients did adverse effects necessitate stopping treatment.

CONCLUSIONS

Three days of co-trimoxazole seems to be as effective as a seven days' course for treating acute urinary tract infection in non-pregnant women.

Single-dose enoxacin compared with 3-day treatment for urinary tract infection

Oral treatment of simple urinary tract infections generally involves 5 to 7 days of antibiotic therapy. This study with enoxacin, a new antibacterial agent of the quinolone-azaquinolone class, investigated the efficacy of a single dose compared with 3 days of treatment. A total of 154 outpatients with symptoms of simple cystitis were treated in an open randomized study with enoxacin, either one 600-mg dose or 200 mg twice a day for 3 days. A urine sample was collected for culture before treatment, 7 to 10 days after treatment, and 4 to 6 weeks after treatment. Seventy-three patients had positive bacterial cultures from the pretreatment urine sample; the predominant pathogen was Escherichia coli, along with a number of other gram-negative organisms and Staphylococcus spp. Of these patients, 33 received a single dose of enoxacin and 40 were treated for 3 days. Follow-up examination at 7 to 10 days showed negative urine cultures in 76% of patients from the single-dose group and 89% from the multiple-dose group, a difference that was not statistically significant (P = 0.665, Fisher's exact test). A number of patients were lost to follow-up at 4 to 6 weeks. However, of those who did attend, only three patients were shown to have relapsed or become reinfected (two in the multiple-dose group and one in the single-dose group). Enoxacin was well tolerated in both groups of patients; the few adverse events were mostly mild.

Ciprofloxacin: chemistry, mechanism of action, resistance, antimicrobial spectrum, pharmacokinetics, clinical trials, and adverse reactions

Ciprofloxacin, considered a benchmark when comparing new fluoroquinolones, shares with these agents a common mechanism of action: inhibition of DNA gyrase. While ciprofloxacin demonstrated a fairly good activity against gram-positive bacteria, it is against gram-negative organisms that it proved to be more potent than other fluoroquinolones. It is the most active quinolone against Pseudomonas aeruginosa, with MIC90s on the order of 0.5 micrograms/ml. When given orally, ciprofloxacin exhibited 70% bioavailability and attained peak serum levels ranging between 1.5 and 2.9 micrograms/ml after a single 500-mg dose. Nineteen percent of an oral dose was excreted as metabolites in both urine and feces. In most cases, body fluids and tissue concentrations equaled or exceeded those in concurrent serum samples. In clinical trials, oral and intravenous ciprofloxacin yielded similar clinical and bacteriologic results compared to standard therapy in a wide array of systemic infections, including lower and upper urinary tract infections; gonococcal urethritis; skin, skin structure, and bone infections; and respiratory tract and gastrointestinal tract infections. Major benefits with the oral form of this quinolone are expected in chronic pyelonephritis and bone infections, and in pulmonary exacerbations in patients with cystic fibrosis. Emergence of ciprofloxacin-resistant microorganisms has been noted in clinical practice, primarily Pseudomonas aeruginosa and Staphylococcus aureus. The most frequent side effects are related to the gastrointestinal tract; but attention should be given to adverse central nervous system effects.