Randomized clinical trial of furazolidone for typhoid fever in children

Efficacy and safety of chloramphenicol: joining the revival of old antibiotics? Systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Chloramphenicol is an old broad-spectrum antibiotic. We assessed its efficacy and safety.

METHODS

This was a systematic review and meta-analysis. Electronic databases were searched to identify randomized controlled trials (RCTs) that assessed patients, of any age, with systemic bacterial infections that can cause sepsis and compared chloramphenicol alone versus other antibiotics. No restrictions on the date of publication, language or publication status were applied. The primary outcome assessed was overall mortality.

RESULTS

Sixty-six RCTs fulfilled the inclusion criteria, and these included 9711 patients. We found a higher mortality with chloramphenicol for respiratory tract infections [risk ratio (RR) 1.40, 95% CI 1.00-1.97] and meningitis (RR 1.27, 95% CI 1.00-1.60), both without heterogeneity. The point estimate was similar for enteric fever, without statistical significance. No statistically significant difference was found between chloramphenicol and other antibiotics regarding treatment failure, except for enteric fever (RR 1.46, 95% CI 1.07-2.00, without heterogeneity). This difference derived mainly from studies comparing chloramphenicol with fluoroquinolones (RR 1.85, 95% CI 1.07-3.2). There were no statistically significant differences between chloramphenicol and other antibiotics in terms of adverse events, including haematological events, except for anaemia, which occurred more frequently with chloramphenicol (RR 2.80, 95% CI 1.65-4.75, I(2) =0%), and gastrointestinal side effects, which were less frequent with chloramphenicol (RR 0.67, 95% CI 0.46-0.99, I(2) =0%). Many of the studies included were sponsored by pharmaceutical companies marketing the comparator drug to chloramphenicol, and this might have influenced the results.

CONCLUSIONS

Chloramphenicol cannot be recommended as a first-line treatment for respiratory tract infections, meningitis or enteric fever as alternatives are probably more effective. Chloramphenicol is as safe as treatment alternatives for short antibiotic courses. RCTs are needed to test this treatment against MDR organisms when better alternatives do not exist.

In vitro activity of nitrofuran derivatives on growth and morphology of Salmonella enterica serotype Enteritidis

AIMS

To evaluate the effect of nitrofuran derivatives furazolidone (Fz) and nitrofurantoin (Nf) on Salmonella enterica serovar Enteritidis PT4 in vitro, with regard to cell growth, morphology and ultrastructure.

METHODS AND RESULTS

The effects of Fz on the growth rates of Fz resistant (FzR) and sensitive (FzS) strains were assessed by viable counts. Over 24 h incubation, concentrations of <1 microg ml(-1) of Fz were bacteriostatic to the FzS strain. The FzR strain tolerated concentrations up to 16 microg ml(-1) before cell numbers diminished over the same time period. The effect on the growth rate of the FzS strain after 1 h exposure to supra-inhibitory concentrations of Fz, gave a maximum response at 32X minimum inhibitory concentration (MIC) of 4.5 h. Effects on the ultrastructure of bacterial cells by scanning electron and transmission microscopy, and DNA-specific staining with DAPI of the FzS strain exposed to nitrofurans were studied. Abnormalities such as extensive filamentation with sparse, sporadic nucleotide distribution and evidence of extrusions in the cell envelope in the form of blebs were evident.

CONCLUSIONS

Nitrofurans exert their bactericidal effect on Salmonella by inducing extensive structural alteration after exposure at sub- or suprainhibitory concentrations, involving inhibition of cell division because of the activated drug causing an intercalating type of binding in DNA.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results demonstrate the in vitro activity of the nitrofuran derivatives, furazolidone and nitrofurantoin on Salmonella, defining the pharmacodynamics and physical nature of their action as therapeutic agents.

Evaluation of treatment and prophylaxis with nitrofurans and comparison with alternative antimicrobial agents in experimental Salmonella enterica Serovar enteritidis infection in chicks

The ability of the nitrofuran antimicrobial agents furazolidone and furaltadone to prevent, reduce or eliminate Salmonella enterica serovar enteritidis PT4 infection in artificially challenged day-old chicks was evaluated. Treating the birds with the nitrofurans failed to eliminate established infections with either furazolidone-resistant (FzR) or furazolidone-sensitive (FzS) strains. Simultaneous administration of the nitrofurans to day-old chicks challenged with FzS failed to prevent infection but reduced colonization significantly (p<0.05) compared to unmedicated controls. No reduction of colonization occurred with FzR. Challenging birds with FzS and simultaneous dosing with nitrofurans for 1 week, followed by a second week of continued treatment, resulted in an increase in the level of colonization in the second week rather than a decrease. Dosing with the nitrofurans (200 ppm) for 1 week prior to challenge with FzS and continued medication for a further week prevented colonization of the caecum, liver and spleen. However, cessation of dosing at the time of challenge with salmonella resulted in colonization. Chloramphenicol and tetracycline at concentrations of 200 ppm were both independently capable of preventing colonization by salmonella. Sulphadiazine initially reduced colonization but failed to eliminate the infection. Only when furazolidone was combined with chloramphenicol or when sulphadiazine was combined with trimethoprim, and the combined drugs were administered concurrently with the challenge, was colonization prevented.

Pharmacological, therapeutic and toxicological properties of furazolidone: some recent research

Some of the recent publications on the pharmacological, therapeutic and toxicological properties of the antimicrobial agent furazolidone (FZ) are briefly reviewed. In animals, most of the recently published papers focus on (1) the methodology of measuring the residues of the drug and its metabolites in edible tissues; (2) the carcinogenicity and genotoxicity of FZ; (3) the cellular and molecular basis of FZ-induced cardiomyopthy, and the action of different cardioprotectant drugs thereon; and (4) hormonal effects. In humans, the use of FZ as an anti-ulcer drug and in controlling infectious diseases, especially opportunistic infections in AIDS patients, is described.

Treatment of typhoid fever with azithromycin versus chloramphenicol in a randomized multicentre trial in India

To compare the clinical and bacteriological efficacies of azithromycin and chloramphenicol for treatment of typhoid fever, 77 bacteriologically evaluable adults, with blood cultures positive for Salmonella typhi or Salmonella paratyphi A susceptible to their assigned drugs, were entered into a randomized open trial at four hospitals in India. Forty-two patients were randomized to receive azithromycin 500 mg p.o. od for 7 days and 35 to receive chloramphenicol 2-3 g p.o. od in four divided doses for 14 days. Thirty-seven patients (88%) in the azithromycin group responded with clinical cure or improvement within 8 days and 30 patients (86%) in the chloramphenicol group responded with cure or improvement. By day 14 after the start of treatment, all patients treated with azithromycin and all except two of the patients treated with chloramphenicol (94%) were cured or improved. Blood cultures repeated on day 8 after start of therapy showed eradication of organisms in 100% of patients in the azithromycin group and 94% of patients in the chloramphenicol group. By day 14 the eradication rate in the chloramphenicol group had increased to 97%. Stool cultures on days 21 and 35 after start of treatment showed no prolonged faecal carriage of Salmonella spp. in either group. These results indicate that azithromycin given once daily for 7 days was effective therapy for typhoid fever in a region endemic with chloramphenicol-resistant S. typhi infection and was equivalent in effectiveness to chloramphenicol given to patients with chloramphenicol-susceptible infections.

Azithromycin versus ciprofloxacin for treatment of uncomplicated typhoid fever in a randomized trial in Egypt that included patients with multidrug resistance

To compare clinical and bacteriological efficacies of azithromycin and ciprofloxacin for typhoid fever, 123 adults with fever and signs of uncomplicated typhoid fever were entered into a randomized trial. Cultures of blood were positive for Salmonella typhi in 59 patients and for S. paratyphi A in 3 cases; stool cultures were positive for S. typhi in 11 cases and for S. paratyphi A in 1 case. Multiple-drug resistance (MDR; resistance to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole) was present in isolates of 21 of 64 patients with positive cultures. Of these 64 patients, 36 received 1 g of azithromycin orally once on the first day, followed by 500 mg given orally once daily on the next 6 days; 28 patients received 500 mg of ciprofloxacin orally twice daily for 7 days. Blood cultures were repeated on days 4 and 10 after the start of therapy, and stool cultures were done on days 4, 10, and 28 after the start of therapy. All patients in both groups improved during therapy and were cured. Defervescence (maximum daily temperatures of </=38 degrees C) occurred at the following times [mean +/- standard deviation (range)] after the start of therapy: 3.8 +/- 1.1 (2 to 7) days with azithromycin and 3.3 +/- 1.0 (1 to 5) days with ciprofloxacin. No relapses were detected. Cultures of blood and stool during and after therapy were negative in all cases, except for one patient treated with azithromycin who had a positive blood culture on day 4. These results indicated that azithromycin and ciprofloxacin were similarly effective, both clinically and bacteriologically, against typhoid fever caused by both sensitive organisms and MDR S. typhi.

Multi-drug resistant typhoid fever in hospitalised children. Clinical, bacteriological and epidemiological profiles

A total of 592 children with clinical diagnosis of typhoid fever admitted to the Dr B. C. Roy Memorial Hospital for Children, Calcutta, India during the period between February 1990 and January 1992, were screened for Salmonella typhi by blood culture. S. typhi was isolated from 221 (37.3%) cases. The majority of the strains (92.3%) showed multi-drug resistant (MDR). They were resistant to chloramphenicol, ampicillin, tetracycline and trimethoprim-sulphamethoxazole. However, all the strains were uniformly (100%) susceptible to gentamicin, amikacin, furazolidone, norfloxacin and ciprofloxacin. Minimum inhibitory concentration of the antimicrobial agents against the resistant strains of S. typhi ranged between 200 and > 1600 micrograms/ml. Phage type 0 was most frequently encountered. The rate of isolation of S. typhi was more or less the same in all the pediatric age groups. The majority of the cases came from lower socio-economic classes with poor personal hygiene. Fever was the main presenting feature in all the cases. Other associated features of the MDR typhoid fever cases, who were uncomplicated during admission, were headache (36.0%), chill and rigor (23.2%), diarrhea (37.2%), anorexia (26.2%), vomiting (23.8%), cough (18.0%) and abdominal pain (19.8%). Hepatosplenomegaly was present in 42.4% cases. However, complications were less frequently encountered among the MDR typhoid fever cases who were uncomplicated during admission and treated as in-patients. Fourteen bacteriologically-confirmed MDR typhoid fever cases had jaundice and another 18 cases had an abnormal state of consciousness during admission. Four (2.0%) bacteriologically-confirmed MDR typhoid fever patients died during the period of observation.