Evaluation of new anti-infective drugs for the treatment of diarrhea caused by Giardia lamblia. Infectious Diseases Society of America and the Food and Drug Administration

WITHDRAWN: Drugs for treating giardiasis

BACKGROUND

There can be a high rate of recurrence of disease after initial drug treatment for giardiasis. These drugs also have a range of adverse effects.

OBJECTIVES

The objective of this review was to assess the effects of drug treatments for giardiasis.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, EMBASE, Current Contents, and reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised trials of drug therapy for giardiasis compared with placebo or another drug.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Thirty-four trials were included. Only one trial was without serious methodological flaws. Compared with placebo, drug treatment was associated with an improved cure rate (odds ratio 11.51, 95% confidence interval 2.29 to 57.98). Metronidazole treatment longer than three days had a better parasitological cure rate than other long treatment courses (odds ratio 2.41, 95% confidence interval 1.31 to 4.44), but there was significant heterogeneity between the trials. Available evidence has not detected a difference in cure between single dose therapy and longer treatment courses (odds ratio 0.33, 95% confidence interval 0.08 to 1.34). Within the single dose regimens, the available evidence did not demonstrate a difference in parasitological cure rate between tinidazole and other short therapies (odds ratio 3.39, 95% confidence interval 0.95 to 12.04), but had a higher clinical cure rate (odds ratio 5.33, 95% 2.66 to 10.67).

AUTHORS' CONCLUSIONS

A single dose of tinidazole appears to give the highest clinical cure rate for giardiasis with relatively few adverse effects.

Nitazoxanide in the treatment of Ascaris lumbricoides in a rural zone of Colima, Mexico

Intestinal parasites in Mexico are an endemic problem. A study was conducted in children, teenagers and adults in a rural community in Colima, Mexico to examine the prevalence and intensity of Ascaris lumbricoides infection and to evaluate the parasitological and clinical efficacy of nitazoxanide (NTZ). Two hundred and eighty children, teenagers and adults participated in this study. Parasitological diagnosis from faeces was confirmed by three consecutive stool samples using the floatation concentration Faust method. Egg counts were performed as described by the Kato-Katz technique before and after treatment. A questionnaire was systematically applied to obtain information about socio-economic status and hygienic habits. One hundred and six participants (38%) were diagnosed as harbouring intestinal parasites, and 86 of them (81%) were infected with A. lumbricoides. All patients with ascariasis infections underwent a complete physical examination before and after NTZ treatment. NTZ resolved 88% of the ascariasis cases, with a 89% clinical efficacy, and there was a 97.5% reduction in the levels of morbidity. The most intense infections for A. lumbricoides were found in housewives, and statistically significant associations were found between ascariasis and the absence of drainage and living in houses with dirt floors.

Effect of nitazoxanide in diarrhea and enteritis caused by Cryptosporidium species

BACKGROUND & AIMS

The aim of this study was to evaluate the efficacy of nitazoxanide for the treatment of diarrhea and enteritis caused by Cryptosporidium species in patients 12 years of age and older.

METHODS

A multicenter, randomized, double-blind, placebo-controlled study was conducted in 90 outpatients 12 years of age and older from the Nile Delta region of Egypt. Patients were randomized to receive either one 500 mg tablet or one matching placebo tablet, or 25 mL of nitazoxanide oral suspension (500 mg nitazoxanide), each given twice daily for 3 days. Clinical and microbiologic response rates were evaluated 4 days after completion of treatment.

RESULTS

Twenty-seven (96%) of the 28 patients receiving nitazoxanide tablets responded clinically compared with 11 (41%) of 27 patients who received placebo (P < .0001). Twenty-six (93%) of the 28 patients who received nitazoxanide were free of Cryptosporidium oocysts in each of 2 posttreatment stool samples compared with only 10 (37%) of 27 patients who received placebo (P < .0001). Response rates in patients receiving the tablets and the suspension were comparable (clinical response rate for suspension, 27 of 31 [87%]; microbiologic response rate for suspension, 28 of 31 [90%]).

CONCLUSIONS

These findings show that a 3-day course of nitazoxanide is effective in treating diarrhea and enteritis caused by Cryptosporidium in nonimmunodeficient patients 12 years of age and older.

Effect of nitazoxanide on morbidity and mortality in Zambian children with cryptosporidiosis: a randomised controlled trial

BACKGROUND

Cryptosporidiosis in children in developing countries causes persistent diarrhoea and malnutrition and is associated with increased mortality, but there is no effective treatment. We aimed to assess the effect of nitazoxanide-a new broad-spectrum antiparasitic drug-on morbidity and mortality in Zambian children with diarrhoea due to Cryptosporidium parvum.

METHODS

Children with cryptosporidial diarrhoea who were admitted to the University Teaching Hospital, Lusaka, Zambia, between November, 2000, and July, 2001, and whose parents consented to their having an HIV test were randomly assigned nitazoxanide (100 mg twice daily orally for 3 days) or placebo. The primary endpoint was clinical response on day 7 after the start of treatment. Secondary endpoints included parasitological response by day 10 and mortality at day 8. Analysis was by intention to treat, with exclusion of patients subsequently found to be negative for C parvum or co-infected at baseline. The trial was stratified by HIV serology.

FINDINGS

50 HIV-seropositive and 50 HIV-seronegative children were recruited for the study, four of whom were subsequently excluded. In HIV-seronegative children, diarrhoea resolved in 14 (56%) of 25 receiving nitazoxanide and 5 (23%) of 22 receiving placebo (difference 33%, 95% CI 7-59; p=0.037). C parvum was eradicated from stool in 13 (52%) of 25 receiving nitazoxanide and three (14%) of 22 receiving placebo (38%, 95% CI 14-63; p=0.007). Four children (18%) of 22 in the placebo group had died by day 8, compared with none of 25 in the nitazoxanide group (-18%, -34 to 2; p=0.041). HIV-seropositive children did not benefit from nitazoxanide. Nitazoxanide was not significantly associated with adverse events in either stratum.

INTERPRETATION

A 3-day course of nitazoxanide significantly improved the resolution of diarrhoea, parasitological eradication, and mortality in HIV-seronegative, but not HIV-seropositive, children.

Randomized clinical study of nitazoxanide compared to metronidazole in the treatment of symptomatic giardiasis in children from Northern Peru

BACKGROUND

Enteric infection by Giardia intestinalis is a common cause of diarrhoea world-wide and a significant cause of morbidity in children.

AIM

To compare the efficacy and safety of nitazoxanide and metronidazole in the treatment of diarrhoea caused by G. intestinalis in children.

METHODS

A total of 110 children presenting with diarrhoea caused by G. intestinalis were randomized to treatment with either a 3-day course of nitazoxanide (100 mg b.d., age range 2-3 years; 200 mg b.d., age range 4-11 years) or a 5-day course of metronidazole (125 mg b.d., age range 2-5 years; 250 mg b.d., age range 6-11 years). The patients were followed-up for a determination of clinical response 7 days after the initiation of treatment, and two subsequent stool samples were collected for parasitological examination.

RESULTS

Diarrhoea had resolved in 47 children out of 55 (85%) in the nitazoxanide treatment group before the day 7 follow-up visit, compared to 44 out of 55 (80%) for metronidazole. Diarrhoea resolved within 4 days in most cases. Only mild, transient adverse events were reported.

CONCLUSIONS

A 3-day course of nitazoxanide suspension is as efficacious as a standard 5-day course of metronidazole suspension in treating giardiasis in children.

Drugs for treating giardiasis

BACKGROUND

There can be a high rate of recurrence of disease after initial drug treatment for giardiasis. These drugs also have a range of adverse effects.

OBJECTIVES

The objective of this review was to assess the effects of drug treatments for giardiasis.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline and Embase, Current Contents, reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised trials of drug therapy for giardiasis compared with placebo or another drug.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Thirty-four trials were included. Only one trial was without serious methodological flaws. Compared with placebo, drug treatment was associated with an improved cure rate (odds ratio 11.5, 95% confidence interval 2.3 to 58). Metronidazole treatment longer than three days had a better parasitological cure rate than other long treatment courses (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), but there was significant heterogeneity between the trials. Single dose therapy appeared equally effective as longer treatment courses (odds ratio 0.33, 95% confidence interval 0.08 to 1.34). Within the single dose regimens, tinidazole had a comparable parasitological cure rate to other short therapies (odds ratio 3.4, 95% confidence interval 0.95 to 12), but had a higher clinical cure rate (odds ratio 5.3, 95% 2.7-10.7).

REVIEWER'S CONCLUSIONS

A single dose of tinidazole appears to give the highest clinical cure rate for giardiasis with relatively few adverse effects.