Effect of nitazoxanide for treatment of severe rotavirus diarrhoea: randomised double-blind placebo-controlled trial

Options for improving effectiveness of rotavirus vaccines in developing countries

Rotavirus gastroenteritis is a leading global cause of mortality and morbidity in young children due to diarrhea and dehydration. Over 85% of deaths occur in developing countries. In industrialised countries, 2 live oral rotavirus vaccines licensed in 2006 quickly demonstrated high effectiveness, dramatically reducing severe rotavirus gastroenteritis admissions in many settings by more than 90%. In contrast, the same vaccines reduced severe rotavirus gastroenteritis by only 30-60% in developing countries, but have been proven life-saving. Bridging this "efficacy gap" offers the possibility to save many more lives of children under the age of 5. The reduced efficacy of rotavirus vaccines in developing settings may be related to differences in transmission dynamics, as well as host luminal, mucosal and immune factors. This review will examine strategies currently under study to target the issue of reduced efficacy and effectiveness of oral rotavirus vaccines in developing settings.

Nitazoxanide in Acute Rotavirus Diarrhea: A Randomized Control Trial from a Developing Country

Background. Acute diarrhea is one of the leading causes of childhood mortality, with rotavirus being an important pathogen. Nitazoxanide, an antiparasitic agent, has been shown to inhibit rotavirus. Objective. This double-blind, randomized trial was designed to study the role of nitazoxanide in acute rotavirus diarrhea. Methods. Of 174 children (12 months to 5 years) with acute diarrhea, 50 rotavirus positive cases were randomized. The intervention group received syrup nitazoxanide twice daily (100 mg in 12–47 months, 200 mg in ≥4 yr) for 3 days along with standard treatment of diarrhea. Duration of diarrhea was the primary outcome measure. Results. The median duration (hrs) of diarrhea (54 versus 80; 95% CI: –26 [–13.2 to –38.8]) and hospitalization (68 versus 90; 95% CI: –22 [–12.98 to –31.02]) was significantly shorter in the nitazoxanide group. No significant difference was seen in the median duration (hrs) of fever or vomiting or the proportion of children requiring parenteral rehydration. There was no report of any adverse events. Conclusions. Oral nitazoxanide is effective and safe in the management of acute rotavirus diarrhea in Indian children (CTRI REF/2016/10/012507).

Synthesis and pre-clinical studies of new amino-acid ester thiazolide prodrugs

Thiazolides are polypharmacology agents with at least three mechanisms of action against a broad spectrum of parasites, bacteria and viruses. In respiratory viruses they inhibit the replication of orthomyxoviridae and paramyxoviridae at a post-translational level. Nitazoxanide 1a, the prototype thiazolide, was originally developed as an antiparasitic agent and later repurposed for the treatment of viral respiratory infections. The second generation thiazolides following nitazoxanide, such as the 5-chloro analogue RM-5038 2a, are also broad-spectrum antiviral agents as we have reported. Both 1a and its effective circulating metabolite, tizoxanide 1b, are 5-nitrothiazole derivatives, while RM-5038 2a and its de-acetyl derivative RM-4848 2b are the corresponding 5-chloro derivatives. Recently 1a has completed phase II-III clinical trials in the United States, Canada, Australia and New Zealand in a total of 2865 adults and adolescents of at least 12 months of age with viral acute respiratory illness. Since its biodisposition is primarily seen in the gastro-intestinal tract, its efficacy in systemic viral diseases requires relatively high oral doses. The chemical synthesis of new derivatives with a better systemic absorption was therefore urgently needed. In order to improve their systemic absorption, new amino-ester prodrug derivatives of 1b and RM4848 2b were prepared and tested for their animal pharmacology, pharmacokinetics and toxicology. RM-5061 8a in rats showed 7-fold higher blood concentration compared to 1a: absolute bioavailability increased from 3 to 20%, with a good safety profile in animal safety pharmacology and toxicology.

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An effective phenolic prodrug for the antiviral agent tizoxanide and a 5-Cl analogue is described.

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These derivatives employ the amino-acid L-tertiary-leucine.

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The stability of this prodrug significantly exceeds that of the Val or Ile analogues.

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Good blood levels are obtainable by oral or IV administration.

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The compounds show a good safety profile.

In vitro Antiviral Activity of Rubia cordifolia Aerial Part Extract against Rotavirus

The root of Rubia cordifolia has been used traditionally as a hemostatic agent, while the aerial part of the plant consisting of leaf and stem is known to exhibit anti-diarrheal properties and has been widely used as a remedy in many parts of China. As rotavirus is one of the most commonly associated diarrhea-causing pathogen, this study aims to investigate the anti-rotaviral effect of R. cordifolia aerial part (RCAP). The cytotoxicity of RCAP toward MA-104 cells was evaluated using the WST-8 assay. Colloidal gold method and real time polymerase chain reaction (qPCR) assay were used to confirm the findings of the antiviral assay. Then, 4',6-diamidino-2-phenylindole (DAPI) staining method was subsequently used to investigate the mode of death among the cells. And the representative components of aqueous extract were isolated and identified. It was shown that both the viability of MA-104 cells and the viral load were reduced with increasing concentration of the extract. DAPI staining showed that virus-induced apoptosis was the cause of the low cell viability and viral load, an effect which was accelerated with incubation in the aqueous herbal extract. The major compounds postulated to exhibit this activity were isolated from the aqueous herbal extract and identified to be compounds Xanthopurpurin and Vanillic Acid. This study showed that RCAP extract effectively inhibited rotavirus multiplication by promoting virus-induced apoptosis in MA-104 cells.

Norovirus: new developments and implications for travelers' diarrhea

Noroviruses are the leading cause of acute gastroenteritis in the United States and are responsible for at least 50 % of acute gastroenteritis outbreaks occurring worldwide each year. In addition, noroviruses have caused outbreaks on cruise ships, in nursing homes and hospitals, and in deployed military personnel, but its role in the etiology of travelers’ diarrhea is not well defined. The aim of this review is to describe the role of noroviruses in travelers’ diarrhea in terms of epidemiology, current diagnostics, treatment and vaccine development efforts. Studies have shown prevalence rates of noroviruses in travelers’ diarrhea cases ranging from 10–65 %. It is likely that norovirus prevalence rates are highly underestimated in travelers’ diarrhea due to rapid onset, short duration of the illness, limited availability of laboratory facilities, and the fact that most clinical laboratories lack the diagnostic capability to detect noroviruses in stool. Further, additional studies are needed to accurately determine the true prevalence rates of norovirus as an etiologic agent of diarrhea among travelers to different regions around the world. With the rapid progress in the development of a norovirus vaccine, travelers could serve as an ideal population for future norovirus clinical trials.

Controlling Rotavirus-associated diarrhea: Could single-domain antibody fragments make the difference?

Group A Rotavirus (RVA) remains a leading cause of severe diarrhea and child mortality. The variable domain of camelid heavy chain antibodies (VHH) display potent antigen-binding capacity, have low production costs and are suitable for oral therapies. Two sets of anti-RVA VHHs have been developed: ARP1-ARP3; 2KD1-3B2. Here, we explore the potential of both sets as a prevention strategy complementary to vaccination and a treatment option against RVA-associated diarrhea in endangered populations. Both sets have been expressed in multiple production systems, showing extensive neutralizing capacity against strains of RVA in vitro. They were also tested in the neonatal mouse model with various degrees of success in preventing or treating RVA-induced diarrhea. Interestingly, mitigation of the symptoms was also achieved with freeze-dried ARP1, so that it could be applied in areas where cold chains are difficult to maintain. 3B2 was tested in a pre-clinical trial involving gnotobiotic piglets where it conferred complete protection against RVA-induced diarrhea. ARP1 was used in the first clinical trial for anti-RVA VHHs, successfully reducing stool output in infants with RVA diarrhea, with no detected side effects.

Short communication: Nitazoxanide inhibits HIV viral replication in monocyte-derived macrophages

We document the anti-HIV activity of nitazoxanide (NTZ), the first member of the thiazolide class of antiinfective drugs, originally effective against enteritis caused by Cryptosporidium parvum and Giardia lamblia. NTZ has been administered extensively worldwide, with no severe toxicities associated with its use. Here, we show for the first time that NTZ decreases HIV-1 replication in monocyte-derived macrophages (MDM) if present before or during HIV-1 infection. This NTZ effect is associated with downregulation of HIV-1 receptors CD4 and CCR5, and increasing gene expression of host cell anti-HIV resistance factors APOBEC3A/3G and tetherin. As NTZ is already in clinical use for other conditions, this newly described anti-HIV activity in MDM may facilitate innovative intensification strategies against HIV-1 when combined with current antiretroviral drug regimens.

Synergistic effect of nitazoxanide with neuraminidase inhibitors against influenza A viruses in vitro

The emergence of drug-resistant influenza A virus (IAV) strains represents a serious threat to global human health and underscores the need for novel approaches to anti-influenza chemotherapy. Combination therapy with drugs affecting different IAV targets represents an attractive option for influenza treatment. We have previously shown that the thiazolide anti-infective nitazoxanide (NTZ) inhibits H1N1 IAV replication by selectively blocking viral hemagglutinin maturation. Herein we investigate the anti-influenza activity of NTZ against a wide range of human and avian IAVs (H1N1, H3N2, H5N9, H7N1), including amantadine-resistant and oseltamivir-resistant strains, in vitro. We also investigate whether therapy with NTZ in combination with the neuraminidase inhibitors oseltamivir and zanamivir exerts synergistic, additive, or antagonistic antiviral effects against influenza viruses. NTZ was effective against all IAVs tested, with 50% inhibitory concentrations (IC50s) ranging from 0.9 to 3.2 μM, and selectivity indexes (SIs) ranging from >50 to >160, depending on the strain and the multiplicity of infection (MOI). Combination therapy studies were performed in cell culture-based assays using A/Puerto Rico/8/1934 (H1N1), A/WSN/1933 (H1N1), or avian A/chicken/Italy/9097/1997 (H5N9) IAVs; dose-effect analysis and synergism/antagonism quantification were performed using isobologram analysis according to the Chou-Talalay method. Combination index (CI) analysis indicated that NTZ and oseltamivir combination treatment was synergistic against A/Puerto Rico/8/1934 (H1N1) and A/WSN/1933 (H1N1) IAVs, with CI values ranging between 0.39 and 0.63, independently of the MOI used. Similar results were obtained when NTZ was administered in combination with zanamivir (CI=0.3 to 0.48). NTZ-oseltamivir combination treatment was synergistic also against the avian A/chicken/Italy/9097/1997 (H5N9) IAV (CI=0.18 to 0.31). Taken together, the results suggest that regimens that combine neuraminidase inhibitors and nitazoxanide exert synergistic anti-influenza effects.

Inhibition of rotavirus ECwt infection in ICR suckling mice by N-acetylcysteine, peroxisome proliferator-activated receptor gamma agonists and cyclooxygenase-2 inhibitors

Live attenuated vaccines have recently been introduced for preventing rotavirus disease in children. However, alternative strategies for prevention and treatment of rotavirus infection are needed mainly in developing countries where low vaccine coverage occurs. In the present work, N-acetylcysteine (NAC), ascorbic acid (AA), some nonsteroidal anti-inflammatory drugs (NSAIDs) and peroxisome proliferator-activated receptor gamma (PPARγ) agonists were tested for their ability to interfere with rotavirus ECwt infectivity as detected by the percentage of viral antigen-positive cells of small intestinal villi isolated from ECwt-infected ICR mice. Administration of 6 mg NAC/kg every 8 h for three days following the first diarrhoeal episode reduced viral infectivity by about 90%. Administration of AA, ibuprofen, diclofenac, pioglitazone or rosiglitazone decreased viral infectivity by about 55%, 90%, 35%, 32% and 25%, respectively. ECwt infection of mice increased expression of cyclooxygenase-2, ERp57, Hsc70, NF-κB, Hsp70, protein disulphide isomerase (PDI) and PPARγ in intestinal villus cells. NAC treatment of ECwt-infected mice reduced Hsc70 and PDI expression to levels similar to those observed in villi from uninfected control mice. The present results suggest that the drugs tested in the present work could be assayed in preventing or treating rotaviral diarrhoea in children and young animals.

N-Acetylcysteine treatment of rotavirus-associated diarrhea in children

Rotaviruses are the leading cause of severe, acute, and dehydrating diarrhea affecting children under 5 years of age worldwide. Despite an important reduction in rotavirus-caused deaths as a consequence of the rotavirus vaccine, alternative or complementary strategies for preventing or treating rotavirus-associated diarrhea are needed mainly in the poorest countries. We describe the cases of four rotavirus-unvaccinated 12-13-month-old girls and a 5-year-old boy who developed rotavirus-associated diarrhea confirmed by enzyme-linked immunosorbent assay, Western blotting, and immunochemistry analyses. After the first day of diarrheal episodes, three of the five patients were immediately administered oral N-acetylcysteine (NAC) 60 mg/kg daily, divided into three equal doses every 8 hours. The other two patients did not receive NAC and served as controls. Administration of NAC resulted in a decreased number of diarrheal episodes, excretion of fecal rotavirus antigen, and resolution of symptoms after 2 days of treatment. Our results suggest that NAC treatment after the first diarrheal episode could be an efficient strategy for treating rotavirus-affected children and preventing the associated severe life-threatening accompanying dehydration.

Nitazoxanide: a first-in-class broad-spectrum antiviral agent

Originally developed and commercialized as an antiprotozoal agent, nitazoxanide was later identified as a first-in-class broad-spectrum antiviral drug and has been repurposed for the treatment of influenza. A Phase 2b/3 clinical trial recently published in The Lancet Infectious Diseases found that oral administration of nitazoxanide 600mg twice daily for five days reduced the duration of clinical symptoms and reduced viral shedding compared to placebo in persons with laboratory-confirmed influenza. The same study also suggested a potential benefit for subjects with influenza-like illness who did not have influenza or other documented respiratory viral infection. From a chemical perspective, nitazoxanide is the scaffold for a new class of drugs called thiazolides. These small-molecule drugs target host-regulated processes involved in viral replication. Nitazoxanide is orally bioavailable and safe with extensive post-marketing experience involving more than 75 million adults and children. A new dosage formulation of nitazoxanide is presently undergoing global Phase 3 clinical development for the treatment of influenza. Nitazoxanide inhibits a broad range of influenza A and B viruses including influenza A(pH1N1) and the avian A(H7N9) as well as viruses that are resistant to neuraminidase inhibitors. It is synergistic with neuraminidase inhibitors, and combination therapy with oseltamivir is being studied in humans as part of ongoing Phase 3 clinical development. Nitazoxanide also inhibits the replication of a broad range of other RNA and DNA viruses including respiratory syncytial virus, parainfluenza, coronavirus, rotavirus, norovirus, hepatitis B, hepatitis C, dengue, yellow fever, Japanese encephalitis virus and human immunodeficiency virus in cell culture assays. Clinical trials have indicated a potential role for thiazolides in treating rotavirus and norovirus gastroenteritis and chronic hepatitis B and chronic hepatitis C. Ongoing and future clinical development is focused on viral respiratory infections, viral gastroenteritis and emerging infections such as dengue fever.

Nitazoxanide, an antiviral thiazolide, depletes ATP-sensitive intracellular Ca(2+) stores

Nitazoxanide (NTZ) inhibits influenza, Japanese encephalitis, hepatitis B and hepatitis C virus replication but effects on the replication of other members of the Flaviviridae family has yet to be defined. The pestivirus bovine viral diarrhoea virus (BVDV) is a surrogate model for HCV infection and NTZ induced PKR and eIF2α phosphorylation in both uninfected and BVDV-infected cells. This led to the observation that NTZ depletes ATP-sensitive intracellular Ca(2+) stores. In addition to PKR and eIF2α phosphorylation, consequences of NTZ-mediated Ca(2+) mobilisation included induction of chronic sub-lethal ER stress as well as perturbation of viral protein N-linked glycosylation and trafficking. To adapt to NTZ-mediated ER stress, NTZ treated cells upregulated translation of Ca(2+)-binding proteins, including the ER chaperone Bip and the cytosolic pro-survival and anti-viral protein TCTP. Depletion of intracellular Ca(2+) stores is the primary consequence of NTZ treatment and is likely to underpin all antiviral mechanisms attributed to the thiazolide.

Treatment of norovirus infections: moving antivirals from the bench to the bedside

Noroviruses (NV) are the most common cause of acute gastrointestinal illness in the United States and worldwide. The development of specific antiviral countermeasures has lagged behind that of other viral pathogens, primarily because norovirus disease has been perceived as brief and self-limiting and robust assays suitable for drug discovery have been lacking. The increasing recognition that NV illness can be life-threatening, especially in immunocompromised patients who often require prolonged hospitalization and intensive supportive care, has stimulated new research to develop an effective antiviral therapy. Here, we propose a path forward for evaluating drug therapy in norovirus-infected immunocompromised individuals, a population at high risk for serious and prolonged illness. The clinical and laboratory features of norovirus illness in immunocompromised patients are reviewed, and potential markers of drug efficacy are defined. We discuss the potential design of clinical trials in these patients and how an antiviral therapy that proves effective in immunocompromised patients might also be used in the setting of acute outbreaks, especially in confined settings such as nursing homes, to block the spread of infection and reduce the severity of illness. We conclude by reviewing the current status of approved and experimental compounds that might be evaluated in a hospital setting.

Nitazoxanide Use as Part of an Empiric Multi-Drug Regimen in Treating Children with Suspected Helicobacter pylori Infection

Helicobacter pylori, a Gram-negative bacterium found in the human stomach, is often present in patients with chronic gastritis. Traditional treatment for H. pylori infection includes metronidazole or clarithromycin, both being associated with development of resistance. In this retrospective report, we describe our clinical experience using a multi-drug treatment regimen for pediatric H. pylori that included nitazoxanide, a newer nitrothiazole benzamide compound used in treating intestinal protozoa infections. Charts were identified for patients who were treated between January 1, 2008 and December 31, 2013 with an ICD-9-CM code 041.86 (H. pylori) and who underwent elective endoscopy. All patients were exposed to nitazoxanide for 3 days plus azithromycin, and cefixime (or another 3rd-generation oral cephalosporin) for 7–10 days, plus a proton pump inhibitor for 30 days. The clinical cure criteria were predefined. There were 127 individual occurrences or cases identified for inclusion in the review, with 111 occurrences meeting the inclusion criteria. The success rate or clinical cure for the new therapy combination prescribed as defined prior to the chart review was 99 out of 111 cases (89.2%). There were no serious adverse events observed or reported during the treatment of any patient. Approximately 10% of patient charts reflected minor complaints of nausea, vomiting or abdominal cramps during the time of active drug therapy. Nitazoxanide appears to be an effective and well-tolerated option for use in combination with other agents to treat H. pylori-induced gastritis.

Nitazoxanide inhibits the replication of Japanese encephalitis virus in cultured cells and in a mouse model

BACKGROUND

Japanese encephalitis virus (JEV) has a significant impact on public health. An estimated three billion people in 'at-risk' regions remain unvaccinated and the number of unvaccinated individuals in certain Asian countries is increasing. Consequently, there is an urgent need for the development of novel therapeutic agents against Japanese encephalitis. Nitazoxanide (NTZ) is a thiazolide anti-infective licensed for the treatment of parasitic gastroenteritis. Recently, NTZ has been demonstrated to have antiviral properties. In this study, the anti-JEV activity of NTZ was evaluated in cultured cells and in a mouse model.

METHODS

JEV-infected cells were treated with NTZ at different concentrations. The replication of JEV in the mock- and NTZ-treated cells was examined by virus titration. NTZ was administered at different time points of JEV infection to determine the stage at which NTZ affected JEV replication. Mice were infected with a lethal dose of JEV and intragastrically administered with NTZ from 1 day post-infection. The protective effect of NTZ on the JEV-infected mice was evaluated.

FINDINGS

NTZ significantly inhibited the replication of JEV in cultured cells in a dose dependent manner with 50% effective concentration value of 0.12 ± 0.04 μg/ml, a non-toxic concentration in cultured cells (50% cytotoxic concentration = 18.59 ± 0.31 μg/ml). The chemotherapeutic index calculated was 154.92. The viral yields of the NTZ-treated cells were significantly reduced at 12, 24, 36 and 48 h post-infection compared with the mock-treated cells. NTZ was found to exert its anti-JEV effect at the early-mid stage of viral infection. The anti-JEV effect of NTZ was also demonstrated in vivo, where 90% of mice that were treated by daily intragastric administration of 100 mg/kg/day of NTZ were protected from a lethal challenge dose of JEV.

CONCLUSIONS

Both in vitro and in vivo data indicated that NTZ has anti-JEV activity, suggesting the potential application of NTZ in the treatment of Japanese encephalitis.

Nitazoxanide: nematicidal mode of action and drug combination studies

Intestinal nematodes or roundworms (aka soil-transmitted helminths or STHs) cause great disease. They infect upwards of two billion people, leading to high morbidity and a range of health problems, especially in infected children and pregnant women. Development of resistance to the two main classes of drugs used to treat intestinal nematode infections of humans has been reported. To fight STH infections, we need new and more effective drugs and ways to improve the efficacy of the old drugs. One promising alternative drug is nitazoxanide (NTZ). NTZ, approved for treating human protozoan infections, was serendipitously shown to have therapeutic activity against STHs. However, its mechanism of action against nematodes is not known. Using the laboratory nematode Caenorhabditis elegans, we show that NTZ acts on the nematodes through avr-14, an alpha-type subunit of a glutamate-gated chloride ion channel known for its role in ivermectin susceptibility. In addition, a forward genetic screen to select C. elegans mutants resistant to NTZ resulted in isolation of two NTZ resistant mutants that are not in avr-14, suggesting that additional mechanisms are involved in resistance to NTZ. We found that NTZ combines synergistically with other classes of anthelmintic drugs, i.e. albendazole and pyrantel, making it a good candidate for further studies on its use in drug combination therapy of STH infections. Given NTZ acts against a wide range of nematode parasites, our findings also validate avr-14 as an excellent target for pan-STH therapy.

Novel approaches and challenges to treatment of central nervous system viral infections

Existing and emerging viral central nervous system (CNS) infections are major sources of human morbidity and mortality. Treatments of proven efficacy are currently limited predominantly to herpesviruses and human immunodeficiency virus (HIV). Development of new therapies has been hampered by the lack of appropriate animal model systems for some important viruses and by the difficulty in conducting human clinical trials for diseases that may be rare, or in the case of arboviral infections, often have variable seasonal and geographic incidence. Nonetheless, many novel approaches to antiviral therapy are available, including candidate thiazolide and pyrazinecarboxamide derivatives with potential broad‐spectrum antiviral efficacy. New herpesvirus drugs include viral helicase‐primase and terminase inhibitors. The use of antisense oligonucleotides and other strategies to interfere with viral RNA translation has shown efficacy in experimental models of CNS viral disease. Identifying specific molecular targets within viral replication cycles has led to many existing antiviral agents and will undoubtedly continue to be the basis of future drug design. A promising new area of research involves therapies based on enhanced understanding of host antiviral immune responses. Toll‐like receptor agonists and drugs that inhibit specific cytokines as well as interferon preparations have all shown potential therapeutic efficacy. Passive transfer of virus‐specific cytotoxic T lymphocytes has been used in humans and may provide an effective therapy for some herpesvirus infections and potentially for progressive multifocal leukoencephalopathy. Humanized monoclonal antibodies directed against specific viral proteins have been developed and in several cases evaluated in humans in settings including West Nile virus and HIV infection and in pre‐exposure prophylaxis for rabies. Ann Neurol 2013;74:412–422

Anti-rotavirus protein reduces stool output in infants with diarrhea: a randomized placebo-controlled trial

BACKGROUND & AIMS

Rotavirus infection is a leading cause of morbidity and mortality in children younger than 5 years of age. Current treatment options are limited. We assessed the efficacy of a llama-derived, heavy-chain antibody fragment called anti-rotavirus protein (ARP1), in modifying the severity and duration of diarrhea in male infants with rotavirus infection.

METHODS

We performed a double-blind, placebo-controlled trial of 176 male infants (6-24 months old) with severe rotavirus-associated diarrhea at Dhaka Hospital, Bangladesh. The infants were randomly assigned to groups given oral ARP1 (15-30 mg/kg/day, n = 88) or placebo (maltodextrin, n = 88) for a maximum of 5 days. The primary outcomes were severity (stool output) and duration of diarrhea and fecal excretion of rotavirus. Secondary outcomes were intake of oral rehydration salt solution, severity of vomiting, and serum levels of rotavirus-specific IgA.

RESULTS

In infants with only rotavirus infection, total cumulative stool output was 305.47 g/kg body weight among those given placebo (n = 63) and 237.03 g/kg body weight among those given ARP1 (n = 61) (a difference of 68.44 g/kg body weight or 22.5%; 95% confidence interval: 18.27-118.59 g/kg body weight; P =.0079). There was a significant reduction in rate of stool output (g/kg/d) in the ARP1 group compared with the placebo group (61%; P = .002). ARP1 had no significant effect in infants with concomitant infections or on any other measured outcomes. No adverse events could be linked to ARP1.

CONCLUSIONS

In a placebo-controlled trial, ARP1 reduced stool output in male infants with severe rotavirus-associated diarrhea. Clinicaltrials.gov number: NCT01259765.

Thiazolides, a new class of antiviral agents effective against rotavirus infection, target viral morphogenesis, inhibiting viroplasm formation

Rotaviruses, nonenveloped viruses presenting a distinctive triple-layered particle architecture enclosing a segmented double-stranded RNA genome, exhibit a unique morphogenetic pathway requiring the formation of cytoplasmic inclusion bodies called viroplasms in a process involving the nonstructural viral proteins NSP5 and NSP2. In these structures the concerted packaging and replication of the 11 positive-polarity single-stranded RNAs take place to generate the viral double-stranded RNA (dsRNA) genomic segments. Rotavirus infection is a leading cause of gastroenteritis-associated severe morbidity and mortality in young children, but no effective antiviral therapy exists. Herein we investigate the antirotaviral activity of the thiazolide anti-infective nitazoxanide and reveal a novel mechanism by which thiazolides act against rotaviruses. Nitazoxanide and its active circulating metabolite, tizoxanide, inhibit simian A/SA11-G3P[2] and human Wa-G1P[8] rotavirus replication in different types of cells with 50% effective concentrations (EC50s) ranging from 0.3 to 2 μg/ml and 50% cytotoxic concentrations (CC50s) higher than 50 μg/ml. Thiazolides do not affect virus infectivity, binding, or entry into target cells and do not cause a general inhibition of viral protein expression, whereas they reduce the size and alter the architecture of viroplasms, decreasing rotavirus dsRNA formation. As revealed by protein/protein interaction analysis, confocal immunofluorescence microscopy, and viroplasm-like structure formation analysis, thiazolides act by hindering the interaction between the nonstructural proteins NSP5 and NSP2. Altogether the results indicate that thiazolides inhibit rotavirus replication by interfering with viral morphogenesis and may represent a novel class of antiviral drugs effective against rotavirus gastroenteritis.

Treatment and prevention of rotavirus infection in children

Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. No antiviral therapy is available. Treatment of rotavirus gastroenteritis is limited to rehydration therapy. Recently, therapies, such as probiotics, have been developed as adjuncts to rehydration therapy. Two effective rotavirus vaccines are available and recommended for routine immunization of all infants. These vaccines have been introduced in both developed and developing countries. As rotavirus vaccines are implemented, studies that assess health impact, indirect benefits, and strain changes after the introduction of rotavirus vaccine have been reported. In the United States, rotavirus vaccination has led to dramatic drops in severe rotavirus-related hospitalizations and has reduced emergency room visits. Herd immunity has also been noted after routine rotavirus immunization. There have been no significant strain shifts or escape mutants noted since the introduction of rotavirus vaccines.

Diagnosis and management of gastrointestinal complications in adult cancer patients: evidence-based guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Cancer patients frequently suffer from gastrointestinal complications. However, a comprehensive, practical and evidence-based guideline on this issue is not yet available.

PATIENTS AND METHODS

An expert group was put together by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) to develop a guideline on gastrointestinal complications in cancer patients. For each subtopic, a literature search was carried out in PubMed, Medline and Cochrane databases and the strength of recommendation and the quality of the published evidence for major therapeutic strategies were categorized using a modification of the 'Infectious Diseases Society of America' criteria. Consensus discussions were held on each of the topics.

RESULTS

Recommendations were made with respect to non-infectious and infectious gastrointestinal complications. For all recommendations, the strength of the recommendation and the level of evidence are presented.

CONCLUSION

This guideline is an evidence-based approach to the diagnosis and management of gastrointestinal complications in cancer patients.

Niclosamide is a proton carrier and targets acidic endosomes with broad antiviral effects

Viruses use a limited set of host pathways for infection. These pathways represent bona fide antiviral targets with low likelihood of viral resistance. We identified the salicylanilide niclosamide as a broad range antiviral agent targeting acidified endosomes. Niclosamide is approved for human use against helminthic infections, and has anti-neoplastic and antiviral effects. Its mode of action is unknown. Here, we show that niclosamide, which is a weak lipophilic acid inhibited infection with pH-dependent human rhinoviruses (HRV) and influenza virus. Structure-activity studies showed that antiviral efficacy and endolysosomal pH neutralization co-tracked, and acidification of the extracellular medium bypassed the virus entry block. Niclosamide did not affect the vacuolar H(+)-ATPase, but neutralized coated vesicles or synthetic liposomes, indicating a proton carrier mode-of-action independent of any protein target. This report demonstrates that physico-chemical interference with host pathways has broad range antiviral effects, and provides a proof of concept for the development of host-directed antivirals.

Inhibition of rotavirus infection in cultured cells by N-acetyl-cysteine, PPARγ agonists and NSAIDs

Although the current rotavirus vaccines have shown good tolerance and significant efficacy, it would be useful to develop alternative or complementary strategies aimed at preventing or treating acute diarrhoeal disease caused by this viral agent. A variety of antiviral strategies other than vaccines have been assayed for rotavirus infection management. The recently demonstrated sensitivity of rotavirus infectivity to thiol/disulfide reagents prompted assays for screening drugs that potentially affect cellular redox reactions. MA104 or Caco-2 cells were inoculated with the rotavirus strains RRV, Wa, Wi or M69 and then incubated with different concentrations of drugs belonging to a selected group of 60 drugs that are currently used in humans for purposes other than rotavirus infection treatment. Eighteen of these drugs were able to inhibit rotavirus infectivity to different extents. A more systematic evaluation was performed with drugs that could be used in children such as N-acetylcysteine and ascorbic acid, in addition to ibuprofen, pioglitazone and rosiglitazone, all of which affecting cellular pathways potentially needed by the rotavirus infection process. Evidence is provided here that rotavirus infectivity is significantly inhibited by NAC in different cell-culture systems. These findings suggest that NAC has the potential to be used as a therapeutic tool for treatment and prevention of rotavirus disease in children.

Tizoxanide pyridine monosolvate

IN THE TITLE COMPOUND [SYSTEMATIC NAME: 2-hy-droxy-N-(5-nitro-1,3-thia-zol-2-yl)benzamide pyridine monosolvate], C(10)H(7)N(3)O(4)S·C(5)H(5)N, the dihedral angle between the pyridine and benzamide rings is 80.55 (7)°. An intamolecular O-H⋯N hydrogen bond occurs in the tizoxanide. In the crystal, the components are linked by an O-H⋯N hydrogen bond, forming a zigzag chain along the c axis. Aromatic π-π inter-actions between inversion-related pyridine rings [centroid-centroid distance = 3.803 (6) Å] are also observed.

Nitazoxanide for the empiric treatment of pediatric infectious diarrhea

We conducted a double-blind, placebo-controlled clinical trial to demonstrate the efficacy of nitazoxanide suspension for the treatment of presumed infectious diarrhea in children. Eligible patients must have had diarrheal illness lasting 3-29 days. Patients were randomized to receive either nitazoxanide or placebo twice daily for three days. The primary endpoint was time from first dose to resolution of symptoms. One hundred children mean age 3.3 years were enrolled. The median time to resolution of symptoms for nitazoxanide treated patients was 23 hours (IQR 4-48 hours) vs 103.5 hours (IQR 63->168 hours) for placebo (p<0.001). An analysis by disease subset indicated nitazoxanide treated patients had statistically shorter durations of diarrheal illness associated with Giardia lamblia (n=32, p<0.001) and those with no identified enteropathogen (n=38, p=0.008), when compared to placebo. The study medication was well tolerated. Overall, nitazoxanide was effective at reducing the duration of diarrheal illness associated with multiple etiologies, including patients with no identified enteropathogen. These results suggest nitazoxanide may be a viable therapeutic option for the empiric treatment of diarrheal illness in children where the etiology is unknown or presumed to be of infectious origin. Clinical trial registry number NCT01326338.

Rotavirus infection: an update on management and prevention

Rotavirus infection is the most common cause of severe diarrhea disease in infants and young children worldwide and continues to have a major global impact on childhood morbidity and mortality. Vaccination is the only control measure likely to have a significant impact on the incidence of severe dehydrating rotavirus disease. Rotavirus vaccines have reduced the burden of rotavirus disease in the United States. Long-term monitoring will need to continue to assess the effects of rotavirus immunization programs and epidemiologic strain surveillance is necessary to determine whether changes in strain ecology will affect the rotavirus vaccine effectiveness and whether rotaviruses with the ability to evade vaccine immunity emerge.

Validated stability indicating methods for determination of nitazoxanide in presence of its degradation products

Three sensitive, selective and reproducible stability-indicating methods are presented for determination of nitazoxanide (NTZ), a new anti-protozoal drug, in presence of its degradation products. Method A utilizes the first derivative of ratio spectra spectrophotometry by measurement of the amplitude at 364.4 nm using one of the degradation products as a divisor. Method B is a chemometric-assisted spectrophotometry, where principal component regression (PCR) and partial least squares (PLS) were applied. These two approaches were successfully applied to quantify NTZ in presence of degradation products using the information included in the absorption spectra in the range 260–360 nm. Method C is based on the separation of NTZ from its degradation products followed by densitometric measurement of the bands at 254 nm. The separation was carried out on silica gel 60F₂₅₄, using chloroform–methanol–ammonia solution–glacial acetic acid (95:5:1:1 by volume, pH=5.80) as a developing system. These methods are suitable as stability-indicating methods for the determination of NTZ in presence of its degradation products either in bulk powder or in pharmaceutical formulations. Statistical analysis of the results has been carried out revealing high accuracy and good precision.

Inhibitory effects of bile acids and synthetic farnesoid X receptor agonists on rotavirus replication

Rotaviruses (group A rotaviruses) are the most important cause of severe gastroenteritis in infants and children worldwide. Currently, an antiviral drug is not available and information on therapeutic targets for antiviral development is limited for rotavirus infection. Previously, it was shown that lipid homeostasis is important in rotavirus replication. Since farnesoid X receptor (FXR) and its natural ligands bile acids (such as chenodeoxycholic acid [CDCA]) play major roles in cholesterol and lipid homeostasis, we examined the effects of bile acids and synthetic FXR agonists on rotavirus replication in association with cellular lipid levels. In a mouse model of rotavirus infection, effects of oral administration of CDCA on fecal rotavirus shedding were investigated. The results demonstrate the following. First, the intracellular contents of triglycerides were significantly increased by rotavirus infection. Second, CDCA, deoxycholic acid (DCA), and other synthetic FXR agonists, such as GW4064, significantly reduced rotavirus replication in cell culture in a dose-dependent manner. The reduction of virus replication correlated positively with activation of the FXR pathway and reduction of cellular triglyceride contents (r(2) = 0.95). Third, oral administration of CDCA significantly reduced fecal virus shedding in mice (P < 0.05). We conclude that bile acids and FXR agonists play important roles in the suppression of rotavirus replication. The inhibition mechanism is proposed to be the downregulation of lipid synthesis induced by rotavirus infection.

Norovirus gastroenteritis successfully treated with nitazoxanide

Infectious diarrhea is a common occurrence in the immunosuppressed population. We present a 43-year-old individual with large-volume stool output Norovirus acute gastroenteritis in the setting of relapsed refractory acute myelogenous leukemia, hematopoietic stem cell transplantation, and biopsy-proven cutaneous and pulmonary graft-versus-host disease. Therapeutic options such as intravenous immunoglobulin or reduction of immunosuppressants were not a feasible choice. A prompt clinical cure was achieved with nitazoxanide, a broad-spectrum antimicrobial agent. Nitazoxanide may be a safe therapeutic alternative, in which a reduction in immunosuppression may not be a viable option.

Thiazolides as novel antiviral agents. 1. Inhibition of hepatitis B virus replication

We report the syntheses and activities of a wide range of thiazolides [viz., 2-hydroxyaroyl-N-(thiazol-2-yl)amides] against hepatitis B virus replication, with QSAR analysis of our results. The prototypical thiazolide, nitazoxanide [2-hydroxybenzoyl-N-(5-nitrothiazol-2-yl)amide, NTZ] 1 is a broad spectrum antiinfective agent effective against anaerobic bacteria, viruses, and parasites. By contrast, 2-hydroxybenzoyl-N-(5-chlorothiazol-2-yl)amide 3 is a novel, potent, and selective inhibitor of hepatitis B replication (EC(50) = 0.33 μm) but is inactive against anaerobes. Several 4'- and 5'-substituted thiazolides show good activity against HBV; by contrast, some related salicyloylanilides show a narrower spectrum of activity. The ADME properties of 3 are similar to 1; viz., the O-acetate is an effective prodrug, and the O-aryl glucuronide is a major metabolite. The QSAR study shows a good correlation of observed EC(90) for intracellular virions with thiazolide structural parameters. Finally we discuss the mechanism of action of thiazolides in relation to the present results.

Synthesis and antimicrobial evaluation of nitazoxanide-based analogues: identification of selective and broad spectrum activity

A library composed of nitazoxanide-based analogues was synthesized and assayed for increased antibacterial efficacy against the pyruvate-ferredoxin oxidoreductase (PFOR) using microorganisms Helicobacter pylori, Campylobacter jejuni and Clostridium difficile. Derivatives were found to recapitulate and improve activity against these organisms and select analogues were tested for their ability to disrupt the PFOR enzyme directly. The library was also screened for activity against staphylococci and resulted in the identification of analogues capable of inhibiting both staphylococci and all PFOR organisms at low micromolar minimum inhibitory concentrations with low toxicity to human foreskin cells.

The pharmacokinetics of nitazoxanide active metabolite (tizoxanide) in goats and its protein binding ability in vitro

The pharmacokinetics of tizoxanide (T), the active metabolite of nitazoxanide (NTZ), and its protein binding ability in goat plasma and in the solutions of albumin and alpha-1-acid-glycoprotein were investigated. The plasma and protein binding samples were analyzed using a high-performance liquid chromatography (HPLC) assay with UV detection at 360 nm. The plasma concentration of T was detectable in goats up to 24 h. Plasma concentrations vs. time data of T after 200 mg/kg oral administration of NTZ in goats were adequately described by one-compartment open model with first order absorption. As to free T, the values of t(1/2Ka), t(1/2Ke), T(max), C(max), AUC, V/F((c)), and Cl((s)) were 2.51 +/- 0.41 h, 3.47 +/- 0.32 h, 4.90 +/- 0.13 h, 2.56 +/- 0.25 microg/mL, 27.40 +/- 1.54 (microg/mL) x h, 30.17 +/- 2.17 L/kg, and 7.34 +/- 1.21 L/(kg x h), respectively. After beta-glucuronidase hydrolysis to obtain total T, t(1/2ke), C(max), T(max), AUC increased, while the V/F((c)) and Cl((s)) decreased. Study of the protein binding ability showed that T with 4 microg/mL concentration in goat plasma and in the albumin solution achieved a protein binding percentage of more than 95%, while in the solution of alpha-1-acid-glycoprotein, the percentage was only about 49%. This result suggested that T might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.