Efficacy and safety of oral ciprofloxacin for treatment of serious urinary tract infections

Enzyme-powered Janus platelet cell robots for active and targeted drug delivery

Transforming natural cells into functional biocompatible robots capable of active movement is expected to enhance the functions of the cells and revolutionize the development of synthetic micromotors. However, present cell-based micromotor systems commonly require the propulsion capabilities of rigid motors, external fields, or harsh conditions, which may compromise biocompatibility and require complex actuation equipment. Here, we report on an endogenous enzyme-powered Janus platelet micromotor (JPL-motor) system prepared by immobilizing urease asymmetrically onto the surface of natural platelet cells. This Janus distribution of urease on platelet cells enables uneven decomposition of urea in biofluids to generate enhanced chemophoretic motion. The cell surface engineering with urease has negligible impact on the functional surface proteins of platelets, and hence, the resulting JPL-motors preserve the intrinsic biofunctionalities of platelets, including effective targeting of cancer cells and bacteria. The efficient propulsion of JPL-motors in the presence of the urea fuel greatly enhances their binding efficiency with these biological targets and improves their therapeutic efficacy when loaded with model anticancer or antibiotic drugs. Overall, asymmetric enzyme immobilization on the platelet surface leads to a biogenic microrobotic system capable of autonomous movement using biological fuel. The ability to impart self-propulsion onto biological cells, such as platelets, and to load these cellular robots with a variety of functional components holds considerable promise for developing multifunctional cell-based micromotors for a variety of biomedical applications.

Magnetotactic Bacteria Powered Biohybrids Target E. coli Biofilms

Biofilm colonies are typically resistant to general antibiotic treatment and require targeted methods for their removal. One of these methods includes the use of nanoparticles as carriers for antibiotic delivery, where they randomly circulate in fluid until they make contact with the infected areas. However, the required proximity of the particles to the biofilm results in only moderate efficacy. We demonstrate here that the nonpathogenic magnetotactic bacteria Magnetosopirrillum gryphiswalense (MSR-1) can be integrated with drug-loaded mesoporous silica microtubes to build controllable microswimmers (biohybrids) capable of antibiotic delivery to target an infectious biofilm. Applying external magnetic guidance capability and swimming power of the MSR-1 cells, the biohybrids are directed to and forcefully pushed into matured Escherichia coli (E. coli) biofilms. Release of the antibiotic, ciprofloxacin, is triggered by the acidic microenvironment of the biofilm, ensuring an efficient drug delivery system. The results reveal the capabilities of a nonpathogenic bacteria species to target and dismantle harmful biofilms, indicating biohybrid systems have great potential for antibiofilm applications.

Effects of broad-spectrum antibiotics on colonization of gastrointestinal tracts of mice by Candida albicans

Three-month-old, male, Crl:CD1 (ICR) BR mice were fed chow containing Candida albicans or regular chow. Subsequently, both groups were given either antibiotics or normal saline for 10 days. Stool cultures were performed immediately before administration, at the end of antibiotic administration, and 1 week after the discontinuation of antibiotics, to determine the effect on the concentration of C. albicans in the stools. The stools of mice fed C. albicans and given antibiotics had substantially higher Candida counts than those of control mice fed C. albicans and given saline. Significantly higher candidal concentrations were observed in the stools of mice given chloramphenicol compared with those of mice given ciprofloxacin, sulfamethoxazole-trimethoprim, and ampicillin. No mice developed histopathological evidence of local gastrointestinal invasion or disseminated candidiasis. In this mouse model, Candida colonization increases substantially after the administration of antimicrobial agents with broad spectra and anaerobic activities.

Antibiotics affecting gastrointestinal colonization of mice by yeasts

A group of three-month old, male Crl:CD1(ICR) BR mice, was fed chow containing Candida albicans, while another group of the same type of mice was fed regular chow. Both groups were treated subsequently with either antibiotics or normal saline for 10 days. Stool cultures were performed before treatment, at the end of treatment, and one week after the end of treatment, to determine the level of colonization of the gastrointestinal tract by the yeast. The stools of mice fed Candida and treated with antibiotics had substantially higher Candida counts than control mice fed C. albicans and treated with saline. The highest concentrations of the yeast were observed in the stools of mice treated with cefotaxime as compared to those of mice treated with pefloxacin, amikacin and amoxicillin. No Candida was found in the stools of mice fed regular chow and treated with antibiotics or saline. Dissemination of Candida was not observed in the visceral organs of any mouse.

Ciprofloxacin versus trimethoprim-sulfamethoxazole: treatment of community-acquired urinary tract infections in a prospective, controlled, double-blind comparison

In this study, we determined the safety and efficacy of the treatment of adults with urinary tract infection with ciprofloxacin hydrochloride (250 mg twice daily for 10 days) in comparison with trimethoprim-sulfamethoxazole (160 mg of trimethoprim and 800 mg of sulfamethoxazole twice daily for 10 days). Patients with signs and symptoms of urinary tract infection were randomized to receive ciprofloxacin (98 women and 5 men) or trimethoprim-sulfamethoxazole (92 women and 8 men). The success rate of therapy was 91% for both treatment arms of the study. Among seven failures after ciprofloxacin therapy, three were due to relapse of infection and two to side effects that necessitated a change in medication; in addition, two patients had persistent symptoms and required hospitalization. Among the six failures associated with trimethoprim-sulfamethoxazole therapy, four were due to relapse, one to persistence of infection, and one to a side effect that necessitated a change in medication. Among the patients treated with trimethoprim-sulfamethoxazole, 32% had mild or moderate adverse reactions; in comparison, 17% of the ciprofloxacin-treated patients had adverse reactions (P = 0.026). For the treatment of urinary tract infection in adult patients in this study, ciprofloxacin and trimethoprim-sulfamethoxazole were equally effective, but ciprofloxacin was associated with fewer adverse reactions.

Ciprofloxacin. Best use of this new broad-spectrum antibiotic

Resistance to traditional antibiotics is an increasing problem. The introduction of ciprofloxacin (Cipro) has been welcome, because it is safe and effective against many organisms (including drug-resistant ones), can be taken orally, and is well tolerated. Dr Fass provides a complete description of the drug, including its use for infections of the urinary, respiratory, and gastrointestinal tracts; skin and skin structures; and bones and joints.

Ciprofloxacin drug utilization review and prospective drug use evaluation

Ciprofloxacin is a fluoroquinolone antimicrobial with activity against both gram-negative and -positive bacteria including pseudomonal and staphylococcal species. It is the only available oral agent possessing this unique spectrum of activity that achieves serum concentrations adequate to treat a variety of systemic infections. A retrospective drug utilization review and a prospective drug use evaluation of ciprofloxacin were performed to determine if the agent was being used for appropriate indications, to ensure correct dosing and appropriate monitoring, and to determine whether its use is cost effective at the Veterans Administration Medical Center, Cleveland (VAMCC). For the retrospective review, 40 patients' charts were randomly chosen for review from computerized inpatient and outpatient prescription records. Drug use review criteria were developed by the Pharmacy Service and Infectious Disease Section. For the prospective evaluation, data were collected for all inpatient and outpatient requests for ciprofloxacin during a six-month period (May to November 1988) using the same criteria as in the retrospective study. Cost analysis was performed by identification and cost comparison of alternative therapy and by estimating the number of days saved by using appropriate oral therapy. All charts from the retrospective review were found to meet criteria for appropriate use. All patients for whom documented follow-up was performed had microbiologic or clinical cures. In the prospective evaluation, 168 patients were started on ciprofloxacin. Ninety-five percent of patients had appropriate justification for use according to criteria. Drug cost savings for the six-month period was +14,962.54 or +29,925.08/year. This covered drug and minibag acquisition costs only. An estimated 127 hospital days were saved (shortened length of +71,717.00 or +143,434.00/year.(ABSTRACT TRUNCATED AT 250 WORDS)

Peroral treatment with ciprofloxacin of patients with spinal cord lesion and bacteriuria caused by multiply resistant bacteria

Eleven patients, median age 38 years, with spinal cord lesion (SCL) and urinary tract infection (UTI) caused by multiply resistant bacteria entered an open clinical trial of peroral ciprofloxacin 250 mg b.i.d. for 6 days. P. aeruginosa was the most prevalent bacteria. Ciprofloxacin was clinically effective in all patients who had symptoms of UTI at entry. Bacterial eradication was achieved in 9 out of 11 patients immediately after treatment. At 4 weeks post-treatment 5 patients had relapse of bacteriuria with the initial micro-organism and only 2 had long term eradication. One patient had transient elevation of transaminases, but no other adverse reactions were noted. Pharmacokinetic analysis showed that ciprofloxacin was readily absorbed with a terminal half life of 2.5 hours and considerable nonrenal elimination. The urinary concentration of ciprofloxacin was high during the whole dosing interval. Oral treatment with ciprofloxacin is an alternative to parenteral antibiotics in SCL-patients with urinary tract infection caused by resistant bacteria.

Quinolone antibacterial agents for the treatment of genitourinary tract infections

The fluoroquinolones have expanded the therapeutic options available for the treatment of genitourinary tract infections. Their ease of oral administration, favourable pharmacokinetics, low incidence of adverse reactions, and broad spectrum of in vitro activity against aerobic and facultative organisms make them especially suitable for treating bacteriuria, particularly when pathogens are resistant to other available oral agents. Their efficacy has also been established in the treatment of prostatis, gonorrhea and chancroid. They have lower in vitro activity against chlamydia, ureaplasma and anaerobes, and their role in the treatment of non-gonococcal urethritis, vaginitis and acute pelvic inflammatory disease is less well established.

Intravenous/oral ciprofloxacin versus ceftazidime in the treatment of serious infections

Seventy-one adult patients with 72 infections were treated, by random selection, with intravenous/oral ciprofloxacin or intravenously administered ceftazidime. Twenty-seven additional patients with 29 infections who were not appropriate for random assignment were treated in an open study with intravenously administered ciprofloxacin only; the latter infections were generally more serious or were caused by ceftazidime-resistant organisms. The most common doses were ciprofloxacin, 200 mg intravenously and 500 mg orally every 12 hours and ceftazidime, 1 to 2 g intravenously every eight to 12 hours. Forty-seven ciprofloxacin-treated infections and 31 ceftazidime-treated infections were evaluable for determination of efficacy. Infections included lower respiratory tract (21 infections), urinary (37 infections), skin/soft tissue (14 infections), bacteremia/endocarditis (four infections), colitis (one infection), and mastoiditis (one infection). Median minimal inhibitory concentrations of ciprofloxacin and ceftazidime were, respectively: for Enterobacteriaceae, Haemophilus influenzae, and Branhamella catarrhalis, no more than 0.06 and no more than 0.25 micrograms/ml; for Pseudomonas aeruginosa, 0.25 and 4 micrograms/ml; for Enterococcus faecalis, 1 and more than 32 micrograms/ml; and for Staphylococcus aureus, 0.25 and 8 micrograms/ml. Ciprofloxacin, 200 mg intravenously, yielded mean serum concentrations 0.5 and eight hours post-intravenous infusion of 2.3 and 0.7 micrograms/ml, respectively. Satisfactory clinical responses were achieved in 17 (81 percent) of 21 patients with intravenous/oral ciprofloxacin, 22 (71 percent) of 31 patients with ceftazidime, and 20 (77 percent) of 26 patients with intravenous ciprofloxacin. The most common treatment failures occurred in complicated skin/soft-tissue infections treated with intravenous/oral ciprofloxacin, complicated urinary tract infections treated with ceftazidime, and necrotizing P. aeruginosa pneumonia treated with intravenous ciprofloxacin; the pneumonia patients all had respiratory failure and had been previously unresponsive to treatment with other appropriate drugs. Serious adverse reactions were observed in three patients, seizures with intravenous ciprofloxacin in two patients, and Clostridium difficile diarrhea with ceftazidime in one patient. We conclude that sequential intravenous/oral ciprofloxacin and ceftazidime were comparable in efficacy and safety; the ability to change from intravenous to oral therapy is a major convenience. Intravenous ciprofloxacin was useful for more serious infections, often caused by ceftazidime-resistant organisms.

Fluoroquinolone antimicrobial agents

The fluoroquinolones, a new class of potent orally absorbed antimicrobial agents, are reviewed, considering structure, mechanisms of action and resistance, spectrum, variables affecting activity in vitro, pharmacokinetic properties, clinical efficacy, emergence of resistance, and tolerability. The primary bacterial target is the enzyme deoxyribonucleic acid gyrase. Bacterial resistance occurs by chromosomal mutations altering deoxyribonucleic acid gyrase and decreasing drug permeation. The drugs are bactericidal and potent in vitro against members of the family Enterobacteriaceae, Haemophilus spp., and Neisseria spp., have good activity against Pseudomonas aeruginosa and staphylococci, and (with several exceptions) are less potent against streptococci and have fair to poor activity against anaerobic species. Potency in vitro decreases in the presence of low pH, magnesium ions, or urine but is little affected by different media, increased inoculum, or serum. The effects of the drugs in combination with a beta-lactam or aminoglycoside are often additive, occasionally synergistic, and rarely antagonistic. The agents are orally absorbed, require at most twice-daily dosing, and achieve high concentrations in urine, feces, and kidney and good concentrations in lung, bone, prostate, and other tissues. The drugs are efficacious in treatment of a variety of bacterial infections, including uncomplicated and complicated urinary tract infections, bacterial gastroenteritis, and gonorrhea, and show promise for therapy of prostatitis, respiratory tract infections, osteomyelitis, and cutaneous infections, particularly when caused by aerobic gram-negative bacilli. Fluoroquinolones have also proved to be efficacious for prophylaxis against travelers' diarrhea and infection with gram-negative bacilli in neutropenic patients. The drugs are effective in eliminating carriage of Neisseria meningitidis. Patient tolerability appears acceptable, with gastrointestinal or central nervous system toxicities occurring most commonly, but only rarely necessitating discontinuance of therapy. In 17 of 18 prospective, randomized, double-blind comparisons with another agent or placebo, fluoroquinolones were tolerated as well as or better than the comparison regimen. Bacterial resistance has been uncommonly documented but occurs, most notably with P. aeruginosa and Staphylococcus aureus and occasionally other species for which the therapeutic ratio is less favorable. Fluoroquinolones offer an efficacious, well-tolerated, and cost-effective alternative to parenteral therapies of selected infections.

Ciprofloxacin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

Ciprofloxacin is one of a new generation of fluorinated quinolones structurally related to nalidixic acid. The primary mechanism of action of ciprofloxacin is inhibition of bacterial DNA gyrase. It is a broad spectrum antibacterial drug to which most Gram-negative bacteria are highly susceptible in vitro and many Gram-positive bacteria are susceptible or moderately susceptible. Unlike most broad spectrum antibacterial drugs, ciprofloxacin is effective after oral or intravenous administration. Ciprofloxacin has been most extensively studied following oral administration. It attains concentrations in most tissues and body fluids which are at least equivalent to the minimum inhibitory concentration designated as the breakpoint for bacterial susceptibility in vitro. The results of clinical trials with orally and intravenously administered ciprofloxacin have confirmed the potential for its use in a wide range of infections, which was suggested by its in vitro antibacterial and pharmacokinetic profiles. It has proven an effective treatment for many types of systemic infections as well as for both acute and chronic infections of the urinary tract. Ciprofloxacin generally appeared to be at least as effective as alternative orally administered antibacterial drugs in the indications in which they were compared, and in some indications, to parenterally administered antibacterial therapy. However, further studies are needed to fully clarify the comparative efficacy of ciprofloxacin and standard antibacterial therapies. Bacterial resistance to ciprofloxacin develops infrequently, both in vitro and clinically, except in the setting of pseudomonal respiratory tract infections in cystic fibrosis patients. The drug is also well tolerated. Thus, as an orally active, broad spectrum and potent antibacterial drug, ciprofloxacin offers a valuable alternative to broad spectrum parenterally administered antibacterial drugs for use in a wide range of clinical infections, including difficult infections due to multiresistant pathogens.

Ciprofloxacin in management of urinary tract infection

Ciprofloxacin is a new quinolone derivative which is particularly well adapted for the treatment of bacterial urinary tract infection. Virtually all uropathogens are susceptible, and the development of resistance is uncommon. Its pharmacokinetic characteristics reveal that effective concentrations of the drug are easily achieved with twice a day oral therapy in the blood, urine, kidneys, and prostate--even in advanced renal failure. The drug is well tolerated, even with prolonged courses of therapy. It will be particularly useful in the treatment of antibiotic-resistant, complicated, and/or prostatic infection.

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.

The future of new oral antibiotics including the quinolones

It is estimated that more than 110 million dollars' worth of oral antibiotics will have been sold in Canada in 1987. In the next few years several new oral antimicrobial agents will reach the market, including beta-lactamase inhibitors, cephalosporins, monobactams, erythromycins and quinolones. Most of these new agents have a broader spectrum of antibacterial activity than the presently available oral antibiotics. A few have a longer half-life and can be administered once a day. The new oral drugs, especially the quinolones and possibly beta-lactams, will now be used to treat infections that in the past could be treated only parenterally. Exacerbations of pulmonary infections due to Pseudomonas aeruginosa in cystic fibrosis can now be successfully treated at home with the new quinolones. Osteomyelitis, arthritis, pneumonia and pyelonephritis will most likely be treated at home in the future. In severe infections patients will be admitted to hospital for short courses of parenteral therapy, followed by oral treatment. If used appropriately the new oral agents may lead to new approaches to the treatment of infectious diseases.