Giardiasis: A pharmacotherapy review

Jefe del departamento de Microbiología y Parasitología, Hospital Pediatrico Universitario Pedro Borrás, Ciudad de La Habana, CP, Cuba.
Expert Opinion on Pharmacotherapy (Impact Factor: 3.53). 09/2007; 8(12):1885-902. DOI: 10.1517/14656566.8.12.1885
Source: PubMed

ABSTRACT Giardia lamblia, the cause of human giardiasis, is among the most common intestinal protozoa worldwide. Human infection may range from asymptomatic shedding of giardial cysts to symptomatic giardiasis, being responsible for abdominal cramps, nausea, acute or chronic diarrhoea, with malabsorption and failure of children to thrive. At present, treatment options include the nitroimidazoles derivatives; especially metronidazole, which has been the mainstay of treatment for decades and is still widely used. The increasing number of reports of refractory cases with this group of drugs and other antigiardial agents, has raised concern and led to a search for other compounds, some of which have arisen due to the introduction of drugs initially addressed to other diseases. The present article examines some of the most important points of antigiardial pharmacotherapy available at present and the future prospects of development of new agents.

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Available from: Angel A Escobedo, Mar 29, 2014
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    • "Fatty to watery diarrhea is a hallmark of acute and chronic giardiasis that in children may result into malabsorption, failure to thrive and deficit in weight gain. Adult asymptomatic carriers are frequently observed (Adam, 2001; Escobedo and Cimerman, 2007). "
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    ABSTRACT: Albendazole (ABZ) is a therapeutic benzimidazole used to treat giardiasis that targets β-tubulin. However, the molecular bases of ABZ resistance in Giardia duodenalis are not understood because β-tubulin in ABZ-resistant clones lacks mutations explaining drug resistance. In previous work we compared ABZ-resistant (1.35, 8, and 250 μM) and ABZ-susceptible clones by proteomic analysis and eight proteins involved in energy metabolism, cytoskeleton dynamics, and antioxidant response were found as differentially expressed among the clones. Since ABZ is converted into sulphoxide (ABZ-SO) and sulphone (ABZ-SOO) metabolites we measured the levels of these metabolites, the antioxidant enzymes and free thiols in the susceptible and resistant clones. Production of reactive oxygen species (ROS) and levels of ABZ-SO/ABZ-SOO induced by ABZ were determined by fluorescein diacetate-based fluorescence and liquid chromatography respectively. The mRNA and protein levels of antioxidant enzymes (NADH oxidase, peroxiredoxin 1a, superoxide dismutase and flavodiiron protein) in these clones were determined by RT-PCR and proteomic analysis. The intracellular sulfhydryl (R-SH) pool was quantified using dinitrobenzoic acid. The results showed that ABZ induced ROS accumulation in the ABZ-susceptible Giardia cultures but not in the resistant ones whilst the accumulation of ABZ-SO and ABZ-SOO was lower in all ABZ-resistant cultures. Consistent with these findings, all the antioxidant enzymes detected and analyzed were upregulated in ABZ-resistant clones. Likewise the R-SH pool increased concomitantly to the degree of ABZ-resistance. These results indicate an association between accumulation of ABZ metabolites and a pro-oxidant effect of ABZ in Giardia-susceptible clones. Furthermore the antioxidant response involving ROS-metabolizing enzymes and intracellular free thiols in ABZ-resistant parasites suggest that this response may contribute to overcome the pro-oxidant cytotoxicity of ABZ.
    Frontiers in Microbiology 04/2015; 6:286. DOI:10.3389/fmicb.2015.00286 · 3.99 Impact Factor
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    • "In the People’s Republic of China alone, G. intestinalis affects an estimated 28.5 million people every year [1]. The prevalence of G. intestinalis has been estimated at 2–3% in the industrialized world and 20–30% in developing countries [4]. Cryptosporidium spp. is another major causal agent of diarrhoea, primarily affecting immunocompromised individuals such as those infected with HIV [3,5,6]. "
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    ABSTRACT: Background Pathogenic intestinal protozoa infections are common in school-aged children in the developing world and they are frequently associated with malabsorption syndromes and gastrointestinal morbidity. Since diagnosis of these parasites is difficult, prevalence data on intestinal protozoa is scarce. Methods We collected two stool samples from school-aged children on Pemba Island, Tanzania, as part of a randomized controlled trial before and 3 weeks after treatment with (i) single-dose albendazole (400 mg); (ii) single-dose nitazoxanide (1,000 mg); (iii) nitazoxanide-albendazole combination (1,000 mg–400 mg), with each drug given separately on two consecutive days; and (iv) placebo. Formalin-fixed stool samples were examined for the presence of intestinal protozoa using an ether-concentration method to determine the prevalence and estimate cure rates (CRs). Results Almost half (48.7%) of the children were diagnosed with at least one of the (potentially) pathogenic protozoa Giardia intestinalis, Entamoeba histolytica/E. dispar and Blastocystis hominis. Observed CRs were high for all treatment arms, including placebo. Nitazoxanide showed a significant effect compared to placebo against the non-pathogenic protozoon Entamoeba coli. Conclusions Intestinal protozoa infections might be of substantial health relevance even in settings where they are not considered as a health problem. Examination of a single stool sample with the ether-concentration method lacks sensitivity for the diagnosis of intestinal protozoa, and hence, care is indicated when interpreting prevalence estimates and treatment effects.
    Parasites & Vectors 01/2013; 6(1):3. DOI:10.1186/1756-3305-6-3 · 3.43 Impact Factor
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    • "Furazolidone In-vivo World wide Bassily, et al., 1970; Garg, 1972; Wolfe, 1975; Craft et al., 1981; Lerman and Walker, 1982; Murphy and Nelson, 1983; Dupont and Sullivan, 1986; Quiros-Buelna, 1989; Escobedo and Cimerman, 2007; Albendazole In-vivo Bangladesh, Cuba Hall and Nahar, 1993: Canete et al., 2012 Mebendazole In-vivo Cuba Almirall et al., 2011 Fenbendazole In-vivo Belgium Geurden et al., 2010 Secnidazole In-vivo Cuba Almirall et al., 2011 Paromomycin In-vivo, in-vivo Australia, Egypt, Belgium, USA Boreham et al., 1985; Gordts et al., 1985; Hill, 1993); Awadalla et al., 1995 Ethanobotanical agents (Geranium nivem, Pippali rasayana and Piper longum) "
    Article: Giardiasis
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    ABSTRACT: Giardiasis is one of the major gastrointestinal parasitic scourges of all the mammals. Giardia is one of the most prevalent gastrointestinal zoonotic protozoan and millions of people are suffering from giardiasis throughout the world. Giardia lamblia is the most prevalent species and responsible for disease production in all mammals. It is associated with poor hygienic conditions and transmitted through fecal-oral route via contaminated food and water. A variety of drugs are reported to have considerable efficacy against Giardia infections like metronidazole, furazolidone, albendazole, mebendazole and some ethanobotanical agents. Good hygienic and sanitation measures are advised to reduce the contamination of the environment that helps to control the giardiasis. The purpose of this article is to comprehensively review the epidemiology, disease pathology and treatment of this zoonotic disease. © 2013 Friends Science Publishers
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