Clinical experience with ciprofloxacin in the USA

Antibiotic Tissue Penetration in Diabetic Foot Infections A Review of the Microdialysis Literature and Needs for Future Research

Although many antimicrobial agents display good in vitro activity against the pathogens frequently implicated in diabetic foot infections, effective treatment can be complicated by reduced tissue penetration in this population secondary to peripheral arterial disease and emerging antimicrobial resistance, which can result in clinical failure. Improved characterization of antibiotic tissue pharmacokinetics and penetration ratios in diabetic foot infections is needed. Microdialysis offers advantages over the skin blister and tissue homogenate studies historically used to define antibiotic penetration in skin and soft-tissue infections by defining antibiotic penetration into the interstitial fluid over the entire concentration versus time profile. However, only a select number of agents currently recommended for treating diabetic foot infections have been evaluated using these methods, which are described herein. Better characterization of the tissue penetration of antibiotic agents is needed for the development of methods for maximizing the pharmacodynamic profile of these agents to ultimately improve treatment outcomes for patients with diabetic foot infections.

Ciprofloxacin-induced palatal tremor

We describe an 84-year-old man with an unusual clinical presentation of palatal tremor in association with ciprofloxacin treatment. The patient had rhythmical movements not only of the soft palate but also of the face and trunk. Complete resolution of the symptoms occurred 2 days after discontinuation of ciprofloxacin and administration of sodium valproate. This is the first reported case of palatal tremor secondary to the use of ciprofloxacin.

Les insuffisances rénales aiguës aux quinolones. Revue générale à propos d'une observation avec cristallisation liée à la ciprofloxacine

A 58 year-old woman developed an acute renal failure very quickly after ingestion of two 500 mg tablets of ciprofloxacin, without any other identifiable risk factor. Renal biopsy was performed. No sign of acute interstitial nephritis was observed but tubular lesions were found, accompanied by deposits of a brown-yellowish substance identified by infrared microscopy as a ciprofloxacin salt. The outcome was favourable. This observation gives the opportunity to remind the different forms of quinolone-induced renal injury and to discuss the possible ways for preventing renal side-effects related to the quinolone use.

Fluoroquinolone adverse effects and drug interactions

Extensive pharmacologic and clinical development of quinolone antimicrobial agents has resulted in improved antimicrobial activity, pharmacokinetic features, toxicity, and drug-drug interaction profiles. Nalidixic acid and other early quinolones had limited use due to poor pharmacokinetics, relatively narrow antimicrobial spectrum of activity, and frequent adverse effects. Beginning with the development of fluoroquinolones, such as norfloxacin and ciprofloxacin, in the 1980s, the agents assumed a greatly expanded clinical role because of their broad antimicrobial spectrum of action, improved pharmacokinetic properties, and more acceptable safety profile. Although the pharmacokinetics and efficacy of the drugs have improved significantly, a major area of continued emphasis is to further reduce the frequency and severity of adverse events and drug-drug interactions. Older agents such as ciprofloxacin and ofloxacin are still extensively prescribed, but the focus of this article is on the newer fluoroquinolones (levofloxacin and other drugs that have been approved or have been under investigation since approximately 1997).

Fluoroquinolone-induced renal failure

Fluoroquinolones are generally well tolerated, clinically useful antimicrobials. This paper highlights rare, but potentially serious, adverse effects involving the kidney. Other antimicrobials have long been known to cause various forms of nephrotoxicity occurring as allergic interstitial nephritis, granulomatous interstitial nephritis, necrotising vasculitis, allergic tubular nephritis or a tubular necrosis. A Medline search (1985 to May 1999) of ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, trovafloxacin, enoxacin, sparfloxacin, grepafloxacin, gatifloxacin, clinafloxacin and moxifloxacin was conducted to ascertain the incidence and features of fluoroquinolone nephrotoxicity. Unfortunately, the data primarily consist of case reports and temporally related events. The incidence of these adverse effects is hard to estimate, and the cause may be multifactorial. While the use of ciprofloxacin appears to increase the risk, this may be due to its longer and more widespread use when compared with the newer agents.

Penetration of ciprofloxacin into the interstitial space of inflamed foot lesions in non-insulin-dependent diabetes mellitus patients

Interstitial ciprofloxacin concentrations were measured by microdialysis in inflamed foot lesions of non-insulin-dependent diabetes mellitus patients following intravenous administration of 0. 2 g of ciprofloxacin. Interstitial ciprofloxacin concentrations were significantly lower than corresponding serum concentrations. There was no significant difference in the penetration of ciprofloxacin into inflamed and unaffected tissue (area under the concentration-time curve(infection)/area under the concentration-time curve(unaffected tissue) = 0.99 +/- 0.15 [mean +/- standard error], n = 6). Thus, inflammation appears to have little or no effect on the penetration of ciprofloxacin into tissue.

Distribution and antimicrobial activity of ciprofloxacin in human soft tissues

Interstitial ciprofloxacin concentrations in soft tissues were measured by microdialysis following intravenous administration of 200 mg to each of eight healthy volunteers. Interstitial ciprofloxacin concentrations were significantly lower than corresponding total serum drug concentrations; the interstitium-to-serum concentration ratios ranged from 0.55 to 0.73. An in vitro simulation based on interstitial pharmacokinetics showed a substantially lower antimicrobial activity than did the simulation based on serum pharmacokinetics. Thus, ciprofloxacin concentrations at the site of effect may be subinhibitory although effective concentrations are attained in serum.

Outbreaks of salmonellosis in hospitals in England and Wales: 1992-1994

Data from the surveillance scheme of general outbreaks of infectious intestinal disease in England and Wales were used to describe the epidemiology of outbreaks of salmonellosis in hospitals from 1992-1994. Outbreaks of infectious intestinal disease in hospitals accounted for 15% (189/1275) of all outbreaks. A salmonella was the implicated pathogen in 12% (22/189). The mode of transmission was described as mainly person to person in 12 outbreaks, mainly foodborne in eight and equal or unknown proportions of foodborne and person to person in two. The most common strain involved was Salmonella enteritidis PT4 (11 outbreaks). The mean duration of outbreaks was 16 days. The mean attack rate in patients was 25% but varied from 2-67%. Illness was reported in 260 patients, of whom 130 had a laboratory confirmed infection. Eight hundred and twenty-six asymptomatic patients were tested, 31 of whom were positive. The salmonella infection was believed to have contributed to the deaths of five patients. Ill staff (115) were tested and 68 were positive; 1508 well staff were tested and 33 were positive. Outbreaks of salmonellosis in hospitals are preventable. Attack rates can be high and outbreaks are often prolonged, with high morbidity and associated disruption of hospital services. There is need for effective infection control policies, appropriate training of staff, simple surveillance systems and readily available expert advice to ensure outbreaks are rapidly controlled.

Large scale use of ciprofloxacin in the control of a Salmonella outbreak in a hospital for the mentally handicapped

An outbreak of salmonella food poisoning occurred in a hospital for the mentally handicapped in July 1990. Salmonella enteritidis phage type 4 was identified in 101 patients and eight staff. Standard infection control measures were instituted. Ciprofloxacin was given to all resident patients and to all affected staff. The outbreak was rapidly controlled. There were no new cases after ciprofloxacin was started and there were no clinical relapses. Microbiological relapsers were retreated with ciprofloxacin. A gradual return to normal activity was possible and within two months the hospital was functioning normally. No salmonellae have been identified in the hospital since that time, confirming that the organism was eradicated, rather than just temporarily suppressed.

In vitro activity of sparfloxacin and clinafloxacin against multidrug-resistant enterococci

We evaluated the in vitro susceptibility of 140 clinical enterococcal isolates to the quinolones sparfloxacin and clinafloxacin. Isolates included Enterococcus faecalis (107), Enterococcus faecium (29), Enterococcus raffinosus (3), and one Enterococcus gallinarum. There were 111 isolates that showed high-level [minimum inhibitory concentrations (MICs) > or = 2000 micrograms/ml] resistance to gentamicin and were resistant to high levels of all other aminoglycosides; five isolates produced beta-lactamase; 21 isolates were resistant (MIC > or = 16 micrograms/ml) to ampicillin and were not beta-lactamase producers; and 13 strains were resistant (MIC > or = 32 micrograms/ml) to vancomycin. Most strains were susceptible to low concentrations of sparfloxacin and clinafloxacin, with MIC90S of 0.6 microgram/ml and 0.5 micrograms/ml, respectively. There were no inoculum effects. Time-kill experiments were performed with 22 strains; using 2 x MIC at 24 h, a > or = 2 log10 reduction in growth was observed with sparfloxacin and clinafloxacin for 14 and 17 strains, respectively. Time-kill synergism experiments were performed with 15 strains lacking high-level aminoglycoside resistance. In vitro bacterial synergism with the combination of sparfloxacin or clinafloxacin with streptomycin or gentamicin was observed for five and 12 isolates, respectively. The bactericidal activity of sparfloxacin and clinafloxacin suggest that these antibiotics may prove useful for therapy of multidrug resistant enterococci.

A comparison of pefloxacin/metronidazole and doxycycline/metronidazole in the treatment of laparoscopically confirmed acute pelvic inflammatory disease

A double-blind, randomised study was conducted to compare the efficacy and safety of a combination of pefloxacin and metronidazole versus doxycycline and metronidazole in patients with pelvic inflammatory disease (PID). The clinical diagnosis had to be confirmed by laparoscopy before patients were included. Of the 74 patients who fulfilled the clinical criteria for PID, laparoscopy confirmed the diagnosis in only 40 patients (54%). The microorganism most frequently found as causative pathogen was Chlamydia trachomatis. Both treatment groups showed a good response to the study-medication. At discharge 9 patients in the pefloxacin group (45%) were cured and 10 patients (50%) had improved. In the doxycycline group 7 patients (35%) were cured and 10 patients (50%) had improved. Obviously pefloxacin/metronidazole and doxycycline/metronidazole are equally effective in the treatment of PID.

Pharmacokinetic profiles of ciprofloxacin after single intravenous and oral doses

Ciprofloxacin was administered to 12 healthy male volunteers at doses of 300 and 400 mg intravenously (i.v.) and 500 and 750 mg orally in a randomized, double-blind, single-dose, four-period crossover study. On each treatment day, each subject received both oral and i.v. formulations, one of which was a placebo. Blood and urine samples were obtained through 24 h postdose. By each dosing route, the pharmacokinetic profiles were dose proportional. The 400-mg i.v. dose was equivalent to the 500-mg oral dose with respect to the area under the concentration-time curve and was equivalent to the 750-mg oral dose with respect to the maximum concentration of ciprofloxacin in serum. The oral bioavailability was 78.0%. The steady-state volume of distribution averaged 178 liters, and the terminal half-life in serum after i.v. dosing was approximately 4.3 h. Renal clearance accounted for approximately 60% of total body clearance. No significant adverse events were associated with either route of administration.

Antibiotic-resistant enterococci

Enterococci have emerged as an important cause of nosocomial infection. Successful antibiotic treatment of serious enterococcal infection usually depends on the synergistic bactericidal effect achieved by the combination of a cell wall-active agent, such as ampicillin or a glycopeptide, and an aminoglycoside. However, the prevalence of enterococci resistant to one or more of these antibiotics is increasing, and has resulted in serious therapeutic difficulties. The mechanisms of antibiotic resistance, and the epidemiology, laboratory diagnosis and management of infection with antibiotic-resistant enterococci are discussed.

A randomized study of ciprofloxacin versus ceftriaxone in the treatment of nursing home-acquired lower respiratory tract infections

OBJECTIVE

To compare the efficacy and safety of ciprofloxacin and ceftriaxone in patients with nursing home-acquired lower respiratory tract infections requiring initial hospitalization.

DESIGN

Prospective, randomized trial.

SETTING

Extended care nursing homes affiliated with a teaching hospital.

PATIENTS

Fifty patients aged 60 years or older with normal or mildly impaired renal function admitted to the hospital for treatment of lower respiratory tract infections.

INTERVENTIONS

Twenty-four patients received initial therapy with intravenous ciprofloxacin, 200 mg every 12 hours (19 patients) or 400 mg every 12 hours (5 patients) during the acute phase followed by 750 mg orally every 12 hours during the convalescence phase. Twenty-six patients received initial therapy with intravenous ceftriaxone, 2 g every 24 hours during the acute phase followed by 1 g administered intramuscularly every 24 hours during the convalescent phase. The total duration of therapy was 14 days.

MAIN OUTCOME MEASUREMENTS

Successful outcome was defined as resolution or marked improvement in clinical signs and symptoms of lower respiratory tract infection upon completion of the treatment course.

RESULTS

Twelve (50%) of the ciprofloxacin-treated and 14 (54%) of ceftriaxone-treated patients had successful outcomes. Recurrent oropharyngeal aspiration was the reason for treatment failure in most patients refractory to either antibiotic. Mortality during therapy was 8% in each group. From 21 satisfactory sputum specimens collected, S. pneumoniae was the most common isolate, followed by H. influenzae and other Gram-negative bacteria. Ciprofloxacin therapy was well tolerated; ceftriaxone therapy was discontinued in two patients (8%) due to adverse reactions (intramuscular pain and drug fever).

CONCLUSIONS

Sequential intravenous/oral ciprofloxacin appears to be as safe and effective as sequential intravenous/intramuscular ceftriaxone. The optimal dosage of intravenous ciprofloxacin in this patient population appears to be 400 mg every 12 hours; however, additional clinical and pharmacokinetic studies with this regimen are warranted.

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.

Comparison of three dosage regimens of ciprofloxacin in urinary tract infections

Fifty-four patients with complicated UTI were administered ciprofloxacin in doses of 500 mg (30 subjects) and 250 mg (24 subjects) at 12-hour intervals. While a positive effect was noted in 96-100% upon termination of therapy, the effect was still present 3 weeks later in 90% of the high-dose, but only in 71% of the low-dose group. In 23 patients with uncomplicated UTI, a positive effect of the three-day therapy with 100 mg of ciprofloxacin at 12-hour intervals was observed in 91% of subjects. Intolerance to the agent was found in one case only. Development of resistance to ciprofloxacin was not observed.

The fluoroquinolone antibacterial agents

In summary, the last decade has been a highly fertile and productive period in quinolone medicinal chemistry, resulting in major improvements in potency, antibacterial spectra, oral absorption and pharmacokinetic properties as well as an increased knowledge of the molecular features important to conferring these various properties. Very recent discoveries concerning replacements for the 3-carboxylic acid moiety, previously thought to be uniquely essential for activity, to give highly potent antibacterials such as (83) illustrate the potential for new breakthroughs in this field. Among the major goals for future research remains the understanding of the potential cartilage toxicity associated with this class of agents, such that an agent useful for pediatric indications may be developed. Future studies can also be expected to further enhance and refine the level of current insight into the manner by which these agents inhibit the target enzyme on a molecular level.

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.

Safety of oral ciprofloxacin. An update based on clinical trial results

The safety of ciprofloxacin was established on a data base (compiled through the end of 1988) of 9,473 well-documented treatment courses world-wide. The daily dosages ranged between 200 and 2,000 mg orally. Thirty-eight percent of the patients received doses between 1 and 10 mg/kg body weight, 46 percent between 11 and 20 mg/kg, and the remaining 16 percent more than 20 mg/kg body weight daily. Ciprofloxacin was administered to 4,214 women (45 percent) and 5,252 men (55 percent). The duration of treatment ranged from less than two days to more than 90 days. A 600-mg daily dose of ciprofloxacin was used mostly in Japan (2,341 patients). The daily dose of 1,000 mg was administered chiefly in the United States and Europe (2,288 patients). The age of the patients ranged from less than one year to 99 years (mean, 50.6 years). More than 38 percent were older than 60 years. According to COSTART terminology, the following drug-related side effects were observed in the different organ systems: digestive, 4.9 percent; metabolic-nutritional, 4.4 percent; central nervous system, 1.5 percent, skin, 1.1 percent; hemic and lymphatic, 0.9 percent; urogenital, 0.8 percent; body as a whole, 0.5 percent; cardiovascular, 0.2 percent; special senses, 0.2 percent; musculoskeletal, 0.1 percent; and respiratory, 0.1 percent. Several patients had more than one reaction. The total incidence of side effects for the treated patients was 9.3 percent. The vast majority of adverse reactions were mild or moderate (94 percent). Serious side effects were reported for 55 patients (6 percent). Based on the 9,473 courses, the incidence of severe reactions was 0.6 percent. Ciprofloxacin treatment was discontinued due to side effects in 146 patients (1.5 percent), mostly due to gastrointestinal reactions (80 patients). The worldwide data from clinical trials with oral ciprofloxacin clearly demonstrate that the drug is relatively safe, and the side effects are usually mild or moderate in intensity and are reversible.

Ciprofloxacin in patients with bacteremic infections. The Spanish Group for the Study of Ciprofloxacin

The efficacy and safety of ciprofloxacin in the treatment of 68 episodes of bacteremia were studied. Patients were treated intravenously (30 cases), orally (13 cases), or with sequential intravenous/oral therapy (25 cases). Intravenous doses ranged from 200 to 400 mg per day and oral doses ranged from 1,000 to 1,500 mg per day. According to the criteria of McCabe and Jackson, 39 cases had nonfatal and 29 had ultimately fatal underlying diseases. The clinical condition of patients at the start of therapy was critical or poor in 40 cases and fair or good in 28. Sixty-four of the 68 episodes of bacteremia were monomicrobial and the remaining four were polymicrobial. The causative micro-organisms were: Escherichia coli (18 episodes), Pseudomonas aeruginosa (13 episodes), Acinetobacter sp. (10 episodes), Salmonella sp. (seven episodes), Enterobacter sp. (six episodes), Proteus sp. (four episodes), Serratia sp. (four episodes), Haemophilus influenzae (three episodes), Klebsiella sp. (three episodes), Staphylococcus aureus (2 episodes), and Morganella morganii (two episodes). Overall clinical efficacy of ciprofloxacin was 94 percent (64 of 68 patients). Bacteremia persisted in four patients (failure rate of 6 percent). Five organisms persisted: Acinetobacter sp. (two patients), P. aeruginosa (one patient), Enterobacter sp. (one patient), and Serratia sp. (one patient). Side effects were phlebitis associated with intravenous administration (four cases), dizziness (four cases), and superinfection (six cases). Superinfecting organisms and sites were as follows: Enterococcus faecalis, wound (2 cases); Candida sp., urinary tract infection (one case); Acinetobacter anitratus (ciprofloxacin resistant), urinary tract infection (one case); Staphylococcus epidermidis, blood (one case); and Clostridium perfringens, blood (one case). Ciprofloxacin administered either intravenously, orally, or intravenously followed by the oral route is effective therapy in the treatment of severe bacteremic infections.

Intravenous ciprofloxacin therapy in severe infections

Fifty evaluable patients (34 men and 16 women; mean age, 47 years) with severe infections were given intravenous ciprofloxacin (200 mg every 12 hours) for a mean of 14 days. Therapy was continued with oral ciprofloxacin 500 to 750 mg every 12 hours in 34 cases for a mean of 57 days. The sources of the infections were bone and joint (26 patients), respiratory tract (10 patients), urinary tract (four patients), soft tissue (four patients), abdominal (three patients), bacteremia of unknown origin (two patients), and right-sided endocarditis (one patient). Fifteen patients (30 percent) were bacteremic. Causative organisms included Pseudomonas aeruginosa (32 patients), other gram-negative bacilli (18 patients), and gram-positive cocci (nine patients). Minimal inhibitory concentrations ranged between 0.03 and 1 microgram/ml. Mean peak serum concentrations were 1.58 micrograms/ml (intravenous) and 2 micrograms/ml (oral); mean trough serum concentrations were 0.23 micrograms/ml (intravenous) and 0.32 micrograms/ml (oral). Serum bactericidal activity values achieved after intravenous and oral therapy were similar. Response to therapy was evaluated separately in patients with or without osteomyelitis. In 30 patients with infections other than osteomyelitis, clinical cure was achieved in 27 (90 percent), and therapy failure occurred in three patients. In the 20 remaining patients with osteomyelitis, 15 (75 percent) had a satisfactory response, with apparent cure after a mean follow-up of 11 months, whereas five had therapeutical failure (P. aeruginosa became resistant in four of them). Overall, no major adverse effects were encountered. Superinfection by a resistant P. aeruginosa was observed in three patients. Intravenous ciprofloxacin is an effective and safe agent for the therapy of severe infections caused by susceptible 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.

Adverse reactions in a dose-ranging study with a new long-acting fluoroquinolone, fleroxacin

New fluoroquinolones have generally been well tolerated. In a double-blind evaluation of oral fleroxacin, using 400, 600, or 800 mg once daily for 7 days in an ambulatory setting for treatment of uncomplicated genital infections, we encountered unexpectedly high rates of adverse reactions. The objective of this analysis was to determine whether any factors in addition to dose could be found to account for our observations. Adverse reactions developed in 66 (84%) of 79 individuals, and severe reactions arose in 38 (48%). Most frequent were central nervous system reactions (70%), with insomnia being especially frequent (49%); gastrointestinal reactions (39%) and photosensitivity reactions (10%) were also common. Development of any reaction (central nervous system reactions, insomnia, and severe intestinal reactions) was dose related. Development of photosensitivity reactions correlated with an outdoor occupation. No other factors, including usual daily caffeine use, correlated with the development of adverse reactions. In our study, fleroxacin taken as a single daily 600- or 800-mg dose was associated with an unacceptably high rate of adverse reactions. Other studies are required to determine whether this problem is unique to fleroxacin or will occur with higher doses of other fluoroquinolones possessing similar chemical modifications and/or good tissue penetration and very long half-lives.

Susceptibilities of genital mycoplasmas to the newer quinolones as determined by the agar dilution method

The increasing resistance of genital mycoplasmas to tetracycline poses a problem because tetracycline is one of the few antimicrobial agents active against Mycoplasma hominis, Ureaplasma urealyticum, chlamydiae, gonococci, and other agents of genitourinary-tract disease. Since the quinolones are a promising group of antimicrobial agents, the susceptibilities of M. hominis and U. urealyticum to the newer 6-fluoroquinolones were determined by the agar dilution method. Ciprofloxacin, difloxacin, and ofloxacin had good activity against M. hominis, with the MIC for 50% of isolates tested (MIC50) being 1 microgram/ml. Fleroxacin, lomefloxacin, pefloxacin, and rosoxacin had MIC50s of 2 micrograms/ml. Enoxacin, norfloxacin, and amifloxacin had MIC50s of 8 to 16 micrograms/ml, and cinoxacin and nalidixic acid were inactive (MIC50, greater than or equal to 256 micrograms/ml). Overall, the activities of 6-fluoroquinolones for ureaplasmas were similar to those for M. hominis, with MICs being the same or twofold greater. The most active 6-fluoroquinolones against ureaplasmas were difloxacin, ofloxacin, and pefloxacin, with MIC50s of 1 to 2 micrograms/ml. Ciprofloxacin was unusual in that the MIC50 for M. hominis was 1 microgram/ml, whereas the MIC50 for ureaplasmas was 8 micrograms/ml. Since the MIC50s for the most active quinolones approximate achievable concentrations in blood and urine, quinolones have promise in treating mycoplasmal infections.

Clinical experience with ciprofloxacin in the treatment of urinary tract infections: a review

During the clinical development of ciprofloxacin 1,519 treatments of UTI were documented. The most frequent specific diagnoses were uncomplicated UTI (46.6%), followed by non-specified UTI (21.7%), complicated UTI (19.4%), acute pyelonephritis (7.6%) and chronic pyelonephritis (4.1%). 70% of the causative organisms isolated were Enterobacteriaceae (Escherichia coli 38%, Proteus spp. 10% and Klebsiella pneumoniae 10%). Pseudomonas aeruginosa occurred in approximately 20% of the cases and the remaining 10% were gram-positive aerobes. Clinical resolution was achieved in about 90% in all specific diagnoses. The eradication rate for gram-negative Enterobacteriaceae was 93.8%, for P. aeruginosa 81.8% and for gram-positive aerobes 90.2%. Studies comparing ciprofloxacin and standard treatment have shown the high efficacy of ciprofloxacin making it a preferred agent particularly for infections caused by pathogens less susceptible to conventional drugs. According to the experience of clinical trials the recommended ciprofloxacin dose varies between 100 and 500 mg b.i.d. orally depending on the severity of clinical status and the susceptibility of the pathogen.

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.

A survey of clinical experience with ciprofloxacin, a new quinolone antimicrobial

Ciprofloxacin is a new quinolone antimicrobial agent with activity against a broad spectrum of gram-negative and gram-positive organisms, including Pseudomonas aeruginosa and methicillin-resistant strains of staphylococci. The efficacy and safety results of 80 clinical studies of the oral form of ciprofloxacin are reported. Drug safety was assessed in 2236 courses in 2203 adult patients treated primarily in the United States. Data from 1676 courses were suitable for analysis of drug efficacy. The unit dose for most patients ranged from 250 mg to 750 mg (median, 500 mg), usually given every 12 hours. The duration of treatment ranged from 3 to 231 days (median, 10 days). Predominant among 1722 infections were those of the urinary tract (43%), skin structures (29%), and respiratory tract (19%); the remainder were bone and joint infections (5%), bacteremias (2%), and intra-abdominal (1%), gastrointestinal (1%), and pelvic infections (less than 1%). Signs and symptoms of infection resolved in 79% of all cases; a further 15% improved, and 5% failed to improve. Pathogens were eradicated in 89% of urinary tract infections and persisted in 5%; 80% of patients still had sterile urine at the 3-to 6-week follow-up. In 81% of nonurinary tract infections, pathogens were eradicated; they persisted in 11%, and superinfection occurred in less than 5%. After treatment, 89% of the 2253 causative organisms were eradicated and 2% were reduced to clinically insignificant counts; 8% persisted. Of 411 isolates of P. aeruginosa, 77% were eradicated, as were 97% of 421 Escherichia coli and 80% of 248 Staphylococcus aureus isolates. Also eradicated were 95% of 166 Klebsiella, 96% of 139 Proteus mirabilis, 100% of 20 other Proteus, 94% of 123 Enterobacter, 100% of 68 Haemophilus influenzae, 96% of 49 Citrobacter, 89% of 45 Serratia, 95% of 41 Streptococcus pneumoniae, 91% of 43 Salmonella, 100% of 38 Morganella morganii, and 100% of 35 Providencia isolates. Adverse reactions were judged probably or possibly drug-related in 14.8% of courses; drug treatment had to be stopped prematurely in 3.5%. The most frequent reactions were gastrointestinal complaints (chiefly nausea, diarrhea, and vomiting), metabolic disorders (elevated SGOT, SGPT, serum creatinine, or blood urea nitrogen), and nervous system effects (dizziness, light-headedness, restlessness, tremor, and headache). Crystalluria, judged to be related to ciprofloxacin, occurred in two patients.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

Worldwide clinical data on efficacy and safety of ciprofloxacin

During the clinical trials 8,861 patients have been treated with ciprofloxacin worldwide. 3,822 of the therapeutic courses were valid for analysis of efficacy according to FDA standards. The following dosages were usually administered: UTI: 100 to 500 mg twice daily orally or 100 mg twice daily intravenously; RTI: 250 to 1000 mg twice daily orally or 200 mg twice daily intravenously; septicemia: 200 mg intravenously twice daily; gonorrhea: 250 to 500 mg single tablet orally; all other infections: 500 to 1000 mg twice daily orally or 200 mg twice daily intravenously. Ciprofloxacin was administered to 762 courses of lower RTI, 88 courses of upper RTI, 108 courses of bacteremia, 766 courses of skin structure infection, 142 courses of bone and joint infections, 149 courses of intra-abdominal infections, 33 courses of gastrointestinal infections, 1,633 courses of UTI, 49 courses of pelvic infections, 279 courses of STD, mainly gonorrhea, and three courses of meningitis. The clinical response was resolution in 76%, improvement in 18% and failure in only 6%. Bacteriologic response by all sites evaluable: pathogens were eradicated from 74%, markedly reduced in 2%, persisted in 10%. Relapse occurred in 4% and reinfection was observed in another 6%. The overall response was favourable for 90% of the patients. Drug safety was established on a data base of 8,861 courses worldwide. The following side-effects according to COSTART terminology were observed: digestive 5%, metabolic nutritional 4.6%, central nervous 1.6%, skin 1.4%, hemic and lymphatic 1%, cardiovascular 0.4%, body as a whole 0.4%, urogenital 0.3%, special senses 0.3%, musculo-skeletal 0.1%, respiratory 0.08%. Several courses had more than one reaction. Thus the total incidence of side-effects for the treated patient population was 10.2%. Ciprofloxacin is a highly effective drug and a breakthrough in several areas of medical interest. It is relatively safe and side-effects are usually mild or moderate in intensity and transient.

Effect of dose on serum pharmacokinetics of intravenous ciprofloxacin with identification and characterization of extravascular compartments using noncompartmental and compartmental pharmacokinetic models

The effect of dose on the pharmacokinetics of ciprofloxacin in serum and urine following single intravenous doses of 100, 150, and 200 mg was studied in nine healthy volunteers. Mean peak levels in serum were 1.4, 2.0, and 3.2 mg/liter for the 100-, 150-, and 200-mg doses, respectively. The data on concentrations in serum were best described by a three-compartment pharmacokinetic model. The terminal half-life (from noncompartmental analysis) averaged between 4.2 and 4.6 h. Average urinary recovery ranged between 45.8 and 48.1%. The average renal clearance of ciprofloxacin was 2.9- to 3.4-fold greater than the measured creatinine clearance. Total serum and renal clearances decreased with increasing dose; however, this was not statistically significant (P greater than 0.05; repeated-measures analysis of variance). Ciprofloxacin was well tolerated by all subjects. In this dose range, ciprofloxacin pharmacokinetics are independent of dose.

Comparative activities of ciprofloxacin and ceftazidime against Klebsiella pneumoniae in vitro and in experimental pneumonia in leukopenic rats

The antibacterial activities of ciprofloxacin and ceftazidime against Klebsiella pneumoniae in vitro and in vivo were compared. Although there was only a minor difference between the MBCs of both drugs, the bacterial killing rate of ciprofloxacin in vitro was very fast in comparison with that of ceftazidime. Similarly, the intravenous administration of ciprofloxacin at 1 h after bacterial inoculation resulted in effective bacterial killing in the lungs of leukopenic rats. This killing was dose dependent, in contrast to the dose-independent bactericidal effect of ceftazidime. The high antibacterial activity of ciprofloxacin in the lungs as compared with that of ceftazidime was also reflected in its therapeutic efficacy in K. pneumoniae pneumonia and septicemia in leukopenic rats when these infections were treated at 6-h intervals over 4 days, starting at 5 h after bacterial inoculation. Concentrations of ciprofloxacin and ceftazidime in lung tissue were not significantly different. Regarding the antibacterial activity of both drugs against K. pneumoniae in relation to the bacterial growth rate in vitro and in the lungs of leukopenic rats, ciprofloxacin killed K. pneumoniae organisms that were not actively growing, whereas ceftazidime did not. In addition, it was demonstrated that when the intravenous administration of antibiotic was delayed from 1 h up to 24 h after bacterial inoculation, ceftazidime lost its antibacterial activity in the lungs and blood of leukopenic rats, whereas ciprofloxacin was still very effective. These data suggest that the capacity of an antibiotic to kill bacteria at a slow growth rate may be relevant for its therapeutic effect in established infections, in which slowly growing bacteria form a substantial part of the total bacterial population.

Ciprofloxacin

Ciprofloxacin is a new fluorinated quinolone antibiotic with high activity against a wide spectrum of gram-positive and gram-negative bacteria, including methicillin-resistant Staphylococcus aureus, Enterobacteriaceae, and Pseudomonas aeruginosa. Clinical trials using the oral preparation of ciprofloxacin have demonstrated its effectiveness in a wide variety of infections. In addition, extensive clinical trials with the intravenous preparation are underway. In vitro and in vivo studies with ciprofloxacin have reported the incidence of resistant organisms to be very low. In addition, the incidence of ciprofloxacin-related side effects throughout its clinical trials has been minimal. Most reports of side effects have been related to the gastrointestinal tract, such as nausea or vomiting. The incidence of adverse experiences in worldwide clinical trials has been reported to be approximately 6.4 percent.

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

Eighty-three patients with serious urinary tract infections were treated with oral ciprofloxacin. Of these patients, 79 were hospitalized, and 41 had known structural or neurologic abnormalities of the urinary tract. The most common pathogens were members of the family Enterobacteriaceae (MICs, less than or equal to 0.06 microgram/ml), Pseudomonas aeruginosa (MICs, 0.13 to 2 micrograms/ml), and Enterococcus faecalis (MICs, 0.5 to 2 micrograms/ml). Sixty-eight patients were able to be evaluated for determining efficacy; all responded symptomatically, and all urinary pathogens were eradicated on days 3 to 5 of treatment. Five patients, who were treated for a relatively short duration (2 to 10 days), relapsed 5 to 9 days posttreatment. Six patients became colonized with yeasts during treatment, and seven patients developed bacterial reinfections 5 to 9 days posttreatment. All patients whose infections relapsed or who developed infections with new organisms had neurogenic bladders, structural abnormalities of the genitourinary tract, or urinary catheters. There was no instance of bacteria developing resistance during treatment. Ciprofloxacin probably caused nausea with or without vomiting in 7 of the 83 patients, headache in 3 patients, and mild elevation of hepatic enzymes in 2 patients; other adverse reactions were observed but were probably not drug related. Oral ciprofloxacin was effective and safe for the treatment of serious urinary tract infections caused by a variety of bacterial pathogens.

Overview of clinical experience with ciprofloxacin

Ciprofloxacin is a new 4-quinolone antibacterial agent with an extended antibacterial spectrum, enhanced potency and the ability to produce therapeutic serum, tissue and urine concentrations after oral administration. Unlike earlier 4-quinolones, it is active against gram-positive cocci and opportunistic organisms such as Pseudomonas aeruginosa. This overview demonstrates that the oral formulation has been shown to be clinically effective in a broad range of urinary and respiratory infections, gonorrhoea, gastro-intestinal infections including typhoid fever, surgical infections, skin and soft tissue sepsis and in a variety of infections caused by Pseudomonas aeruginosa, notably cystic fibrosis. Adverse reactions are infrequent and in almost every case have proved mild and transient. Ciprofloxacin has great potential for the oral therapy of infections which have traditionally required parenteral chemotherapy.