Ciprofloxacin and norfloxacin, two fluoroquinolone antimicrobials

The chemistry, mechanism of action, antimicrobial spectrum, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of ciprofloxacin and norfloxacin are reviewed, and mechanisms of antimicrobial resistance and drug and laboratory interactions are described. Norfloxacin is the first antimicrobial in the fluoroquinolone class to be marketed in the United States; ciprofloxacin is under investigation in clinical trials. The fluoroquinolones are structurally related to nalidixic acid. The activity and spectrum are enhanced by the addition of 6-fluoro and 7-piperazino substituents. Quinolone antimicrobials appear to inhibit DNA gyrase, an enzyme specific and essential for all bacteria, as their primary mechanism of action. As a result, DNA synthesis is inhibited. Ciprofloxacin and norfloxacin are active against gram-negative enteric bacteria, Pseudomonas aeruginosa, Haemophilus influenzae, and Neisseria gonorrhoeae. Ciprofloxacin has good activity against Staphylcoccus spp., including methicillin-resistant Staph. aureus. Norfloxacin generally is less potent than ciprofloxacin, particularly against Ps. aeruginosa and Staph. aureus. Peak concentrations occur about one to two hours after an oral administration of either drug. Both drugs are widely distributed in body fluids and tissues and are eliminated by renal excretion, metabolism, and biliary excretion. Dosage reductions are required in severe renal dysfunction. Ciprofloxacin and norfloxacin are effective agents for treating urinary-tract infections, including infections caused by Ps. aeruginosa. The recommended dosage of norfloxacin for urinary-tract infections in adults is 400 mg orally every 12 hours; the drug should be given for 7 to 10 days in uncomplicated infections and for 10 to 21 days in complicated ones. The fluoroquinolones may be useful for treating chronic bacterial prostatitis. Ciprofloxacin is potentially useful for treating sexually transmitted diseases. Ciprofloxacin is active against N. gonorrhoeae, including beta-lactamase-producing strains and strains that are resistant to tetracycline, and Chlamydia spp. Use of ciprofloxacin for treating gastrointestinal infections and for selective decontamination of the gastrointestinal tract is promising. In open studies, ciprofloxacin has been effective against a variety of infections caused by susceptible organisms. Resistance to ciprofloxacin has developed during treatment of infections caused by Ps. aeruginosa, Staph. aureus, and Serratia marcescens. The most frequently reported adverse effects of either drug are gastrointestinal complaints, headache, and dizziness.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparative in vitro activity of ciprofloxacin and five other quinoline derivatives against gram-negative isolates

A total of 375 Gram-negative bacterial strains were isolated from midstream urine specimens of the same number of patients affected by urinary tract infections. All bacteria were identified by standard bacteriological methods and their susceptibility to six quinoline derivatives (ciprofloxacin, cinoxacin, norfloxacin, oxolinic acid, pipemidic acid, nalidixic acid) was studied by determining the MICs and MBCs for each compound using a miniaturized dilution broth method in microtitre plates and twofold dilutions of each drug from 256 to 0.12 mcg/ml. Ciprofloxacin, a new quinoline carboxylic acid compound structurally related to nalidixic acid, showed a much higher antibacterial activity against all bacterial strains under examination, including Pseudomonas, than the other compounds, except for norfloxacin. The MIC90 and MBC90 of ciprofloxacin never exceeded 1 mcg/ml with any of the bacterial species; and MBC/MIC ratios were very low, which represents an important clinical advantage. Only norfloxacin showed comparable effectiveness. No bacterial strain showed resistance to the drug and the MIC90 and MBC90 never exceeded 8 mcg/ml.     

The use of norfloxacin in a university hospital

Because of increasing norfloxacin use and the development of resistant organisms, an evaluation was undertaken in a University Hospital to assess the appropriateness of norfloxacin for the treatment of urinary tract infections and to calculate the potential cost savings associated with more cost-effective antibiotic therapy. Medical records of 64 patients receiving norfloxacin for a 31-day period were concurrently reviewed. Of these, 58 patients were treated for urinary tract infections and four patients received urinary tract infection prophylaxis. Fourteen patients were prescribed solely empiric therapy whereas an additional 44 patients received definitive treatment confirmed by culture results. Based on the predetermined criteria, norfloxacin use for the definitive treatment of urinary tract infections was deemed to be appropriate in 34 of the 44 patients. Three additional courses of therapy were also judged to be appropriate due to documented signs and symptoms associated with urinary tract infections, despite cultures with less than 10(5) colony forming units per mL urine. Reasons for inappropriate use in the remaining seven patients included isolation of fewer bacteria than required by the criteria in asymptomatic patients (3 cases), isolation of organisms not sensitive to norfloxacin (1 case) and lack of dosage adjustment for renal insufficiency (3 cases). Nineteen of 32 evaluable inpatients (59%) received norfloxacin when a less expensive, equally effective agent was available. Although savings from more cost-effective therapy of urinary tract infections are minimal, due to the potential emergence of resistant organisms, norfloxacin should be reserved for infections not amenable to treatment with other oral antibiotics.     

Development of Pseudomonas aeruginosa resistance to norfloxacin during therapy

Two elderly patients diagnosed with Pseudomonas aeruginosa urinary tract infections were treated with oral norfloxacin in the recommended dose of 400 mg q12h. Initially, antimicrobial susceptibility data indicated the organisms were sensitive to norfloxacin. Six to eight days into therapy urine cultures became positive for P. aeruginosa once again; this time, however, susceptibility reports indicated the organisms were now resistant to norfloxacin. Since cross-resistance among norfloxacin, other quinolones, and cephalosporins can occur, we recommend repeated urine cultures during and after norfloxacin therapy in elderly patients with complicated P. aeruginosa urinary tract infections.     

Influence of pH and human urine on the antibacterial activity of ciprofloxacin, norfloxacin and ofloxacin

The influence of pH on the antibacterial activity of ciprofloxacin, norfloxacin and ofloxacin was studied in broth and pooled human urine by microdilution susceptibility tests. Selected strains of E. coli, Staphylococcus aureus and Pseudomonas aeruginosa were used as test organisms. The results show that cultivation at pH 5.7 in urine increased the MIC values for all three quinolones 8, 16 and 32-fold compared with broth at pH 7.1. Killing curves show that in urine with 10 mcg/ml ciprofloxacin, rapid killing of E. coli and Pseudomonas aeruginosa occurred, whereas ofloxacin and especially norfloxacin were less effective.     

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

Norfloxacin is one of the new 4-quinolone antibacterial agents. A fluorinated piperazinyl-substituted congener of nalidixic acid, it demonstrates a much wider in vitro antibacterial spectrum and greater potency than the parent compound. Its antibacterial activity against most Gram-negative pathogens is enhanced in comparison to nalidixic acid, but is similar to that of some of the other new 4-quinolones like enoxacin, and slightly less than that of ciprofloxacin. Unlike nalidixic acid, norfloxacin is also active against Pseudomonas aeruginosa and some Gram-positive organisms. In acute or uncomplicated urinary tract infections, norfloxacin has repeatedly been shown to be as effective as co-trimoxazole. Single studies have demonstrated a significantly better bacteriological cure rate with norfloxacin than with pipemidic acid, and similar cure rates with norfloxacin and both a nalidixic acid/sodium citrate mixture and amoxycillin. Similar results were found in a few studies comparing norfloxacin to pipemidic acid or amoxycillin in patients with chronic and/or complicated urinary tract infections. Norfloxacin is as effective as spectinomycin in gonorrhoea due to penicillin-resistant N. gonorrhoeae, and cures bacterial gastroenteritis caused by several gastrointestinal pathogens. Norfloxacin appears to be well tolerated and may have a low propensity to select for bacterial resistance during clinical use, although the latter needs further confirmation.     

In vitro susceptibility of new generation of antibacterial antibiotics against pathogenic bacteria

Antibiotic susceptibility of ten bacteria i.e. Neisseria catarrhalis, Salmonella typhi, S. enteritidis, Haemophilus influenzae, Bacillus subtilis, Pseudomonas fluorescence, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus and E. coli to twenty antibiotics i.e. cefpirom (30 mcg), ceftriaxone (30 mcg), erythromycin (15 mcg), doxycycline (30 mcg) lomefloxacin (10 mcg), sisomicin (30 mcg), vancomycin (30 mcg), augmentin (30 mcg), ampicillin (30 mcg), cotrimoxazole (25 mcg), cefotaxime (30 mcg), Chloramphenicol (30 mcg), cephalexin (30 mcg), tetracycline (30 mcg), ciprofloxacin (5 mcg), nitrofurantoin (300 mcg), nalidixic acid (30 mcg), pefloxacin (10 mcg), norfloxacin and ofloxacin (5 mcg) was studied to evaluate the antimicrobial efficacy of recently introduced second and third generation antibiotics. All the test strains were sensitive to pefloxacin, erythromycin, augmentin and chloramphenicol. Maximum resistance to cefpirom excluding E. coli and S. typhi and co-trimoxazole except S. typhi, Pseudomonas aeruginosa was observed, occasional resistance was seen against ceftriaxone, vancomycin and cefotaxime.     

Comparative study of norfloxacin and trimethoprim for the treatment of elderly patients with urinary tract infection

One hundred elderly hospitalised patients, aged 70 to 97 years (mean 81.7 years; SD 7.1 years) with a urinary tract infection were entered into a randomised study to compare the efficacy, safety and tolerance of norfloxacin 400 mg twice daily for three days with trimethoprim 300 mg once daily for three days. Forty-two of 49 patients (86%) were cured with norfloxacin, compared with 35 of 51 (69%) with trimethoprim (p less than 0.05). No patient reported any side effects during treatment. Two patients treated with norfloxacin and three treated with trimethoprim developed a disturbance of liver function. Three deaths occurred within 28 days of treatment with trimethoprim but were unrelated to the treatment. In this study norfloxacin proved superior to trimethoprim for the treatment of uncomplicated urinary tract infections in elderly hospitalised patients.     

Norfloxacin: clinical pharmacology and clinical use

Norfloxacin, a nalidixic acid analog, is the first of the fluorinated quinolinecarboxylic acids to be marketed in the United States. It demonstrates potent antibacterial activity against aerobic, gram-negative bacteria including the Enterobacteriaceae, gentamicin-resistant Pseudomonas aeruginosa, and penicillin-resistant Neisseria gonorrhoeae. Norfloxacin exhibits good activity against methicillin-resistant and -sensitive Staphylococcus aureus, but less activity against most other aerobic, gram-positive organisms. Anaerobic bacteria are resistant to the drug. Resistance to norfloxacin is not plasmid mediated, but is secondary to bacterial mutation, and occurs less frequently than nalidixic acid resistance. Its pharmacokinetic properties after a 400-mg oral dose consist of a peak serum concentration of 1.3-1.58 micrograms/ml, an elimination half-life of 3-7 hours, and good penetration into kidney and prostatic tissues. Renal excretion is the major route of elimination. Norfloxacin is highly effective in the treatment of uncomplicated and complicated urinary tract infections, and gonococcal urethritis. Adverse effects are generally well tolerated and usually do not require discontinuation of therapy.     

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

Aztreonam (azthreonam; SQ 26,776) is the first member of a new class of beta-lactam antibiotics, the monobactams. Aztreonam is selectively active against Gram-negative aerobic bacteria and inactive against Gram-positive bacteria. Thus, in vitro, aztreonam is inhibitory at low concentrations (MIC90 less than or equal to 1.6 mg/L) against Enterobacteriaceae except Enterobacter species, and is active against Pseudomonas aeruginosa, 90% of pseudomonads being inhibited by 12 to 32 mg/L. Aztreonam is inactive against Gram-positive aerobic bacteria and anaerobes, including Bacteroides fragilis. Therefore, when administered alone, aztreonam has minimal effect on indigenous faecal anaerobes. Aztreonam must be administered intravenously or intramuscularly when used to treat systemic infections, since absolute bioavailability is very low (about 1%) after oral administration. Since elimination half-life is less than 2 hours, 6- or 8-hourly administration is used in the treatment of moderately severe or severe infections, although 12-hourly injection is adequate in less severe systemic and some urinary tract infections. Therapeutic trials have shown aztreonam to be effective in Gram-negative infections including complicated infections of the urinary tract, in lower respiratory tract infections and in gynaecological and obstetric, intra-abdominal, joint and bone, skin and soft tissue infections, uncomplicated gonorrhoea and septicaemia. In comparisons with other antibiotics, aztreonam has been at least as effective or more effective than cefamandole in urinary tract infections and similar in efficacy to tobramycin or gentamicin. Where necessary, aztreonam and the standard drug have both been combined with another antibiotic active against Gram-positive and/or anaerobic bacteria. Aztreonam has been effective in eradicating pseudomonal infections in most patients (except in patients with cystic fibrosis), but the inevitably limited number of pseudomonal infections available for study prevents any conclusions as to the relative efficacy of aztreonam compared with other appropriate regimens against these infections. Thus, with an antibacterial spectrum which differs from that of other antibiotics, aztreonam should be a useful alternative to aminoglycosides or 'third generation' cephalosporins in patients with proven or suspected serious Gram-negative infections.     

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

Ceftazidime is a new 'third generation' cephalosporin administered intravenously or intramuscularly. Similarly to other third generation cephalosporins it has a broad spectrum of in vitro activity against Gram-positive and Gram-negative aerobic bacteria, is particularly active against Enterobacteriaceae (including beta-lactamase-positive strains) and is resistant to hydrolysis by most beta-lactamases. Importantly, in vitro ceftazidime is presently the most active cephalosporin available against Pseudomonas aeruginosa, but it is less active against Staphylococcus aureus than first and second generation cephalosporins. Only larger comparative trials are likely to discern any statistically significant differences in clinical efficacy which may exist between ceftazidime and other antibiotics, but ceftazidime appears to be similar in efficacy to 'standard' comparative drugs in lower respiratory tract infections and complicated and/or chronic urinary tract infections among debilitated or hospitalised patients. Thus, in patients having Gram-negative infections at these sites and in whom the potential toxicity of the aminoglycosides is a concern, ceftazidime may be a valuable alternative in that it apparently lacks serious side effects and does not require routine drug plasma concentration monitoring. In fibrocystic patients having acute respiratory tract infections, ceftazidime is highly effective at both reducing symptoms of infection and temporarily reducing the sputum counts of Pseudomonas species. However, in these patients resistance to ceftazidime may develop, as seen with other beta-lactam antibiotics. In the treatment of fever of unknown origin or documented infections in immunocompromised adults and children, ceftazidime appears to be similar in efficacy to various 2- or 3-drug combinations. Nevertheless, the coadministration of an antibiotic having greater efficacy against Gram-positive bacteria should be considered in immunocompromised patients. Results from a small number of comparative trials suggest that ceftazidime may be as effective as the aminoglycosides in intra-abdominal, obstetric and gynaecological, and skin and soft tissue infections. However, further clinical experience, particularly a few well designed comparative studies, is needed to clarify the comparative efficacy in these conditions as well as in septicaemia/bacteraemia, meningitis, and bone and joint infections.     

In vivo activity of ciprofloxacin, ofloxacin, norfloxacin and pipemidic acid against Escherichia coli infections in mice

The therapeutic efficacy of four quinolones, i.e. ciprofloxacin, ofloxacin, norfloxacin and pipemidic acid, was investigated in experimental infections in mice caused by pipemidic acid-susceptible and -resistant E. coli. For intraperitoneal infections caused by E. coli strain 444 and 23, the efficacy of ciprofloxacin, ofloxacin and norfloxacin was superior to that of pipemidic acid. Furthermore, ciprofloxacin and ofloxacin had higher activity than norfloxacin and pipemidic acid in urinary tract and uterine infections. Serum and uterus levels of ciprofloxacin and ofloxacin in normal mice were higher and more durable than those of norfloxacin.     

In vitro antibacterial activity of imipenem against Pseudomonas and Staphylococcus species. Comparison with thirteen other antimicrobial agents

The in vitro antimicrobial activity of imipenem against recent clinical isolates of Pseudomonas spp. (94 strains) and penicillin-resistant Staphylococcus spp. (50 Staph. aureus and 50 coagulase-negative Staphylococcus) was assessed using the Mueller-Hinton agar dilution method. Results were compared with those simultaneously obtained for amikacin, netilmicin, tobramycin, norfloxacin, piperacillin, ceftazidime, ceftriaxone and azthreonam against Pseudomonas spp., and for rifampicin, clindamycin, netilmicin and cefoxitin, besides penicillin and methacillin, against Staphylococcus spp. About 50 and 90% of 84 Pseudomonas aeruginosa isolates were inhibited by concentrations of imipenem equal to or less than 2 and 8 mg/l respectively. The in vitro activity of imipenem was comparable to that of ceftazidime and norfloxacin, but superior to that of the aminoglycosides and all the other antibiotics tested, in terms of potency by weight. Among other Pseudomonas spp. only P. malthophilia (2 strains) proved resistant to imipenem. Rifampicin was the most active antibiotic by weight against Staph. aureus but imipenem was more active than clindamycin and, especially, netilmicin and cefoxitin. Imipenem was highly active also against coagulase-negative staphylococci, with some differences related to the high incidence of methicillin-resistant strains. MICs of imipenem in Mueller-Hinton broth correlated with those obtained in agar, unlike the aminoglycosides. There were no significant inoculum effects on MICs of imipenem and MBCs were within one twofold dilution of MICs in over 75% of assays.     

Antibacterial efficacy of norfloxacin, trimethoprim-sulfamethoxazole, and gentamicin in experimentally-infected normal and streptozotocin-induced diabetic mice

Systemic bacterial infections due to Escherichia coli MB 2884, Proteus mirabilis MB 3125 and Klebsiella pneumoniae MB 4005 were well controlled by treatment with norfloxacin both in normal and streptozotocin-induced diabetic mice. similar observations were made when trimethoprim-sulfamethoxazole was used against susceptible pathogens. Systemic infection due to Pseudomonas aeruginosa MB 4700 was well controlled by norfloxacin and gentamicin in normal mice; this infection was more refractory to treatment by both drugs in diabetic animals. These observations suggest that norfloxacin may be an effective drug in the treatment of bacterial infections which may occur under diabetic conditions, and further investigation is warranted.     

Chronic dose urinary and serum pharmacokinetics of norfloxacin in the elderly.

1. Norfloxacin was administered as two daily 400 mg oral doses to eight elderly patients requiring treatment for urinary tract infections. Blood specimens were obtained for pharmacokinetic profiles following the first and fifteenth doses. Further specimens were obtained before each morning's dose of norfloxacin. Specimens of urine were obtained to ascertain if adequate antimicrobial concentrations were reached in these patients with diminished renal function. 2. Norfloxacin half-life was consistent with that expected in mild renal impairment and was not different between the first and fifteenth doses. Based on ratios of AUC values, accumulation is probably related to renal function, being greatest for creatinine clearance values below 30 ml min-1. 3. On the great majority of occasions, the urinary concentrations of norfloxacin exceeded 20 micrograms ml-1. On days 2-7, the mean percentage 12 h renal elimination of norfloxacin was 18.6 +/- 1.47 (mean of 82 separate observations). Norfloxacin 400 mg twice daily was well tolerated in this group of elderly patients and produced adequate antimicrobial concentrations in urine.     

Pharmacokinetic, bacteriological and clinical studies in the pediatric field on norfloxacin

We have evaluated norfloxacin (NFLX), a fluoroquinolone agent, in tablet form for its efficacy and safety in the field of pediatrics. 1. Mean serum concentrations of NFLX following oral administration to 3 children at dose levels of 3.2 mg/kg, 3.7 mg/kg and 5.4 mg/kg were, respectively, 0.7 microgram/ml, 0.18 microgram/ml and 0.64 microgram/ml at 2-4 hours. Mean serum half-lives (T1/2) of NFLX were 2.5-2.9 hours and mean urinary recovery rates in the first 6 hours after administrations were 7.1-30.7%, depending on dose levels. 2. Antibacterial activities of NFLX against clinically isolated 30 organisms from children were determined. MIC of NFLX against Staphylococcus aureus was similar to that of ABPC, 0.39-25 micrograms/ml. MIC of NFLX against Escherichia coli was approximately less than or equal to 0.10 microgram/ml. This MIC value was lower than other antibiotics. MIC of NFLX against Vibrio parahaemolyticus was less than or equal to 0.10 microgram/ml. 3. NFLX was administered to 30 patients (7 patients with Salmonella enteritis, 7 patients with Campylobacter enteritis, 5 patients with other enteritis, 1 patient with bacillary dysentery, 8 patients with urinary tract infection, 2 patients with skin soft tissue infection). The clinical responses of these 30 patients were as follows; excellent: 24 patients, good: 4 patients. The efficacy rate was 93.3%. 4. The bacteriological efficacy rate of NFLX against clinically isolated 29 organisms from children was 75.9%, including 3 cases in which other antimicrobial agents had been ineffective. Especially against Salmonella spp. was superior to other agents tested. 5. Neither clinical adverse reaction nor abnormal laboratory data was found in any of these 33 patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antibacterial activity after a single-dose of norfloxacin, ofloxacin and pipemidic acid detected in urine of volunteers

Six healthy volunteers received in a triple-crossover design a single oral dose of norfloxacin, ofloxacin or pipemidic acid. Urine samples were collected during the 24 h following the administration and were tested for inhibitory and bactericidal activity against selected strains of Enterobacteriaceae and Pseudomonas aeruginosa. Norfloxacin and ofloxacin inhibited the urinary growth of sensitive strains during the 24 h of sampling time at dilutions much higher than those generally considered satisfactory. Nalidixic acid was less effective and did not achieve bactericidal activity against Ps. aeruginosa over the interval of 12 to 24 h.     

Basic and clinical studies on norfloxacin in the pediatric field

Pharmacokinetic , bacteriological and clinical studies on norfloxacin (NFLX), a quinolone-carboxylic acid antibacterial agent, were conducted in the pediatric field. 1. Serum concentrations and urinary excretion of NFLX after single dose of 2.2 approximately 5.6 mg/kg (mean 4.4 +/- 1.2 mg/kg) were determined in 13 children with ages between 6 and 11 years. The mean peak serum concentration of the drug was 0.37 +/- 0.20 micrograms/ml at 2 hours after administration. The mean half-life of the drug in serum was 2.8 +/- 0.4 hours and the serum concentration at 8 hours was 0.11 +/- 0.06 micrograms/ml. The mean urinary concentration reached a maximum of 125.2 +2- 166.2 micrograms/ml in pooled urine from 0 to 2 hours and the mean urinary recovery rate in the first 8 hours after administration was 22.1 +/- 6.0%. A dose-response relationship was observed between doses/body weight and peak serum concentrations. 2. The clinical efficacy, bacteriological efficacy and the safety of NFLX were evaluated in 65 pediatric patients with ages between 2 years 10 months and 15 years 7 months with infections. In 62 assessable cases (acute purulent tonsillitis 9 cases, acute pneumonia 3 cases, chronic rhinitis 1 case, urinary tract infections 15 cases, and acute colitis 34 cases), clinical efficacies were excellent in 48 cases, good in 13 cases, and fair in 1 case with an overall efficacy rate of 98.4%. Staphylococcus aureus 1 strain, Staphylococcus epidermidis 1 strain, Escherichia coli 10 strains, Salmonella sp. 5 strains, Morganella morganii 1 strain, Pseudomonas aeruginosa 3 strains, Haemophilus parainfluenzae 1 strain and Campylobacter jejuni 12 strains were isolated from the patients as pathogens. Bacteriologically, all of these strains were eradicated except that 3 strains of C. jejuni only decreased. With regard to side effects, dizziness and nausea were observed in 1 case each but they were slight and the continuation of the treatment was possible. No abnormal laboratory test data were observed. From the above results, NFLX was considered to be a useful drug for the treatment of pediatric infections.     

Laboratory and clinical studies on norfloxacin in pediatrics

Norfloxacin (NFLX, AM-715) is a new quinolone antibacterial agent. In the present study, we carried out laboratory and clinical investigations on NFLX in the field of pediatrics. The obtained results are summarized as follows. 1. NFLX was very active against Escherichia coli, Salmonella sp., Klebsiella sp., Enterobacter sp. and Pseudomonas aeruginosa among Gram-negative rods. Antibacterial activities of NFLX against Gram-positive cocci were lower than those against Gram-negative rods but superior to activities of usual quinolone agents. MIC values of NFLX against Campylobacter jejuni were distributed in a range of less than or equal to 0.05-0.78 micrograms/ml. 2. A peak serum level of 0.49 micrograms/ml was observed in 2 subjects and its urinary recoveries were 13.7%, 21.5%, respectively. 3. Clinical efficacies to NFLX were excellent in 25 patients and good in 9 patients with a efficacy rate of 92%. In a bacteriological examination, causative organisms were eradicated with an eradication rate of 87%. 4. No side effects were observed except eosinophilia in 1 patient. These findings indicate that NFLX will be useful and safe drug against bacterial infections in pediatrics.     

Clinical effects of lividomycin on respiratory tract infections, primarily wet cases of bronchiectasis (author's transl)]

Patients with various respiratory infections, primarily wet cases of bronchiectasis, were treated with lividomycin (LVDM) at a dose of 1 g/day for about a week. The results obtained are as follows: 1. Of the 15 patients with refractory bronchiectasis who had previously been treated with various other antibiotics, 11 patients (73.3%) responded to LVDM. Although there was no patient who responded to LVDM excellently, good cures were achieved in 5 pateints and fair cures in 6 patients. 2. In bronchiectasis patients having infections in association with pulmonary tuberculosis (mixed infections), LVDM did not show any remarkable effects, excepting that fair cures were achieved in 3 patients. 3. In the 7 patients with acute bronchopneumonia, excellent, good and fair cures were achieved in 1, 5 and 1 patient, respectively. Although LVDM was effective in all of the patients with the said infection, the number of the patients responded excellently was meager and the onset of action seemed to be somewhat slow. 4. In one patient with lobar pneumonia, LVDM was not effective. 5. The MIC values of LVDM for clinically isolated various organisms are summarized below: Pseudomonas aeruginosa 50 mcg/ml, Klebsiella pneumoniae 3.13 to 6.25 mcg/ml, Haemophilis influenzae 1.56 to 6.25 mcg/ml, Diplococcus pneumoniae 50 mcg/ml, alpha-Streptococcus 50 to 100 mcg/ml, beta-Streptococcus 100 mcg/ml, and Staphylococcus aureus 1.56 mcg/ml. 6. In spite of the fact that a majority of the patients participated in this study were the aged, LVDM's side effects were limited to an increase of BUN (one patient) and eruption (one patient). Any noticeable changes in hepatic and renal function, hearing acuity, etc. were not observed. As indicated above, LVDM was effective against, respiratory infections as well as infections of the urinary tract on which a considerable number of research has already been reported. Thus, it is considered to be worthwhile to use LVDM for the treatment of respiratory infections.