Triclabendazole and clofazimine reduce replication and spermine uptake in vitro in Toxoplasma gondii.

Toxoplasmosis is a worldwide zoonosis caused by the protozoan parasite Toxoplasma gondii. Although this infection is generally asymptomatic in immunocompetent individuals, it can cause serious clinical manifestations in newborns with congenital infection or in immunocompromised patients. As current treatments are not always well tolerated, there is an urgent need to find new drugs against human toxoplasmosis. Drug repurposing has gained considerable momentum in the last decade and is a particularly attractive approach for the search of therapeutic alternatives to treat rare and neglected diseases. Thus, in this study, we investigated the antiproliferative effect of several repurposed drugs. Of these, clofazimine and triclabendazole displayed a higher selectivity against T. gondii, affecting its replication. Furthermore, both compounds inhibited spermine incorporation into the parasite, which is necessary for the formation of other polyamines. The data reported here indicate that clofazimine and triclabendazole could be used for the treatment of human toxoplasmosis and confirms that drug repurposing is an excellent strategy to find new therapeutic targets of intervention.

Crystal violet structural analogues identified by in silico drug repositioning present anti-Trypanosoma cruzi activity through inhibition of proline transporter TcAAAP069.

BACKGROUND: Crystal violet (CV) was used for several years in blood banks to eliminate the parasite Trypanosoma cruzi in endemic areas in order to prevent transfusion-transmitted Chagas disease. One mechanism of action described for CV involves inhibition of proline uptake. In T. cruzi, proline is essential for host cell infection and intracellular differentiation among other processes, and can be obtained through the proline permease TcAAAP069. METHODOLOGY/PRINCIPAL FINDINGS: CV inhibited proline transporter TcAAAP069 and parasites overexpressing this permease were 47-fold more sensitive to this compound than control parasites. Using CV as reference molecule, loratadine, cyproheptadine, olanzapine and clofazimine were identified as structurally related compounds to CV (structural analogues) by in silico drug repurposing through a similarity-based virtual screening protocol. All these already-approved drugs for clinical use inhibited TcAAAP069 activity with different efficacies and also presented trypanocidal action in epimastigotes, trypomastigotes and amastigotes of the Y, CL Brener and Dm28c T. cruzi strains. Finally, a synergistic effect between benznidazole and the CV chemical analogues was evidenced by combination and dose-reduction indexes values in epimastigotes and trypomastigotes of the Y strain. CONCLUSIONS/SIGNIFICANCE: Loratadine, cyproheptadine and clofazimine inhibit TcAAAP069 proline transporter and also present trypanocidal effect against all T. cruzi life stages in strains from three different DTUs. These CV structural analogues could be a starting point to design therapeutic alternatives to treat Chagas disease by finding new indications for old drugs. This approach, called drug repurposing is a recommended strategy by the World Health Organization to treat neglected diseases, like Chagas disease, and combination therapy may improve the possibility of success of repositioned drugs.

Computer-guided drug repurposing: identification of trypanocidal activity of clofazimine, benidipine and saquinavir.

In spite of remarkable advances in the knowledge on Trypanosoma cruzi biology, no medications to treat Chagas disease have been approved in the last 40 years and almost 8 million people remain infected. Since the public sector and non-profit organizations play a significant role in the research efforts on Chagas disease, it is important to implement research strategies that promote translation of basic research into the clinical practice. Recent international public-private initiatives address the potential of drug repositioning (i.e. finding second or further medical uses for known-medications) which can substantially improve the success at clinical trials and the innovation in the pharmaceutical field. In this work, we present the computer-aided identification of approved drugs clofazimine, benidipine and saquinavir as potential trypanocidal compounds and test their effects at biochemical as much as cellular level on different parasite stages. According to the obtained results, we discuss biopharmaceutical, toxicological and physiopathological criteria applied to decide to move clofazimine and benidipine into preclinical phase, in an acute model of infection. The article illustrates the potential of computer-guided drug repositioning to integrate and optimize drug discovery and preclinical development; it also proposes rational rules to select which among repositioned candidates should advance to investigational drug status and offers a new insight on clofazimine and benidipine as candidate treatments for Chagas disease. One Sentence Summary: We present the computer-guided drug repositioning of three approved drugs as potential new treatments for Chagas disease, integrating computer-aided drug screening and biochemical, cellular and preclinical tests.

OFLOXACIN multicentre trial in MB leprosy FUAM-Manaus and ILSL-Bauru, Brazil.

UNLABELLED: Recently antimicrobials of the fluoroquinolone class (pefloxacin and ofloxacin) were found far more effective against Mycobacterium leprae in studies with both mice and patients than dapsone and clofazimine. As multicentre trial participants, we evaluated the therapeutic efficacy, in terms of rate of relapse, of two new multidrug regimens containing ofloxacin, comparing them to 1 year and 2 years of standard WHO-MDT regimen in multibacillary (MB) leprosy patients. A total of 198MB patients were recruited to participate in a randomized, double-blind trial. Among those, 53 patients were treated with 1 year of WHO-MDT (a regimen including dapsone, clofazimine, and rifampin), 55 patients received 1 year of WHO-MDT plus an initial 1 month of daily ofloxacin, 63 patients were treated with 1 month of daily rifampin and daily ofloxacin, whereas 27 were treated with 2 years of WHO-MDT. Patients were regularly monitored for signs of relapse, in at least 7 years follow-up after being released from treatment. RESULTS: Relapse occurred in those treated with 1-month regimen alone at a significant higher rate (P < 0.001): 388%, whereas in the other three regimens that included WHO-MDT it ranged from 0 to 5%. This study found that a short-course treatment for MB patients with rifampicin-ofloxacin combination had a higher failure rate. The addition of one month of daily ofloxacin to 12 months MB WHO-MDT did not increase its efficacy.

Use of clofazimine in dermatology.

Clofazimine is the riminophenazine dye that, due to its antibacterial and anti-inflammatory properties, has been used for several diseases. This article reviews all major characteristics and uses relating to clofazimine, from its pharmacology to its indications in several skin diseases, over and above its classical and well established use in the treatment of leprosy. Due to its anti-inflammatory and antimicrobial properties, clofazimine has a wide spectrum for application in dermatology. The indications include neutrophilic, granulomatous and infectious diseases. Although it is not the first-choice medication in most of the cases, clofazimine should always be considered among the therapeutic options in refractory cases.

[Hematological, hemostatic and biochemical alterations induced by clofazimine and clarithromycin, in single and multiple doses, in rats]. / Alterações hematológicas, hemostáticas e bioquímicas induzidas pela clofazimina e claritromicina, em doses única e múltiplas, em ratos.

Clarithromycin and clofazimine have been used to treat leprosy, tuberculosis and infections caused by the Mycobacterium avium complex. Since there is a scarcity of data on the toxicity of therapeutic regimens that include these drugs, this study had the aim of determining the adverse effects of these therapies, through evaluation of hematological, hemostatic and biochemical parameters. The drugs were administered to male Wistar rats, as monotherapy, in regimens of single and multiple doses. Clarithromycin caused increases in the numbers of mononuclear and polymorphonuclear leukocytes. Both of the drugs inverted the proportions between mononuclear and polymorphonuclear cells and increased the numbers of polymorphonuclear cells and degenerating cells. Clofazimine and clarithromycin prolonged the prothrombin time and clarithromycin also prolonged the activated partial thromboplastin time. Clarithromycin caused increases in total and direct bilirubin. Both of the drugs increased the plasma levels of gamma-glutamyltransferase. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and hepatic changes.

Alterações hematológicas, hemostáticas e bioquímicas induzidas pela clofazimina e claritromicina, em doses única e múltiplas, em ratos / Hematological, hemostatic and biochemical alterations induced by clofazimine and clarithromycin, in single and multiple doses, in rats

Claritromicina e clofazimina têm sido utilizadas no tratamento da hanseníase, tuberculose e infecções causadas pelo complexo Mycobacterium avium. Como os dados sobre a toxicidade de esquemas terapêuticos que incluem estes fármacos são escassos, este estudo teve como objetivo determinar os efeitos adversos destas terapias, por meio da avaliação dos parâmetros hematológicos, hemostáticos e bioquímicos. Os fármacos foram administrados em ratos machos Wistar, em monoterapia, em regime de doses única e múltipla. Claritromicina provocou aumento de leucócitos mono e polimorfonucleares. Ambos os fármacos inverteram a proporção entre células mono e polimorfonucleares e provocaram aumento do número de células polimorfonucleares e células em degeneração. Clofazimina e claritromicina prolongaram o tempo de protrombina e claritromicina também prolongou o tempo de tromboplastina parcial ativa. Claritromicina causou aumento de bilirrubinas total e direta e, ambos os fármacos, elevaram os níveis plasmáticos de gama-glutamiltransferase. Portanto, clofazimina e claritromicina induzem alterações hematológicas, hemostáticas e hepáticas.

Clarithromycin and clofazimine have been used to treat leprosy, tuberculosis and infections caused by the Mycobacterium avium complex. Since there is a scarcity of data on the toxicity of therapeutic regimens that include these drugs, this study had the aim of determining the adverse effects of these therapies, through evaluation of hematological, hemostatic and biochemical parameters. The drugs were administered to male Wistar rats, as monotherapy, in regimens of single and multiple doses. Clarithromycin caused increases in the numbers of mononuclear and polymorphonuclear leukocytes. Both of the drugs inverted the proportions between mononuclear and polymorphonuclear cells and increased the numbers of polymorphonuclear cells and degenerating cells. Clofazimine and clarithromycin prolonged the prothrombin time and clarithromycin also prolonged the activated partial thromboplastin time. Clarithromycin caused increases in total and direct bilirubin. Both of the drugs increased the plasma levels of gamma-glutamyltransferase. Therefore, clofazimine and clarithromycin induce hematological, hemostatic and hepatic changes.

Mycobacterium kansasii: antibiotic susceptibility and PCR-restriction analysis of clinical isolates.

Mycobacterium kansasii is the second most common cause of non-tuberculosis mycobacterial diseases in Sao Paulo, Brazil. An important component of the management of infections caused by this organism is antibiotic susceptibility testing. The objective of this study was to determine the drug susceptibility profiles and genotypes of clinical isolates of M. kansasii obtained from patients with or without an infection that met the American Thoracic Society's case definition criteria of M. kansasii disease. One hundred and sixty-nine clinical isolates of M. kansasii collected between 1993 and 1998 in Sao Paulo, Brazil, were tested consecutively. The isolates were genotyped by PCR restriction-enzyme pattern analysis (PRA). Most of the M. kansasii strains were susceptible to isoniazid, streptomycin, rifabutin, rifampicin, clarithromycin, ethionamide, amikacin, clofazimine and cycloserine, and resistant to ethambutol, ciprofloxacin and doxycycline. Of 169 isolates, 167 belonged to the type I PRA genotype and one each belonged to type II and III genotypes. There was no correlation between PRA subtype and M. kansasii disease according to the American Thoracic Society case definition. Clinical trials may be needed to better correlate MIC values with treatment outcomes to identify appropriate parameters for drug-resistance testing of M. kansasii.

Efficacy of clofazimine - modified cyclodextrin against Mycobacterium avium complex in human macrophages

Clofazimine, a water insoluble substituted iminophenazine derivative with anti-mycobacterial and anti-inflammatory activity, is recommended by the WHO for the treatment of leprosy. It is also active against disseminated Mycobacterium avium complex (MAC) disease in HIV-infected patients. Recently, we achieved a 4000-fold increase of clofazimine water solubility using a novel modified clofazimine-cyclodextrin complex synthesized and patented by our group [Wasserlösliche, Iminiophenazinderivate enthaltende pharmazeutische Zusammensetzungen, deren Herstellung und Verwendung, German Patent, DE19814814C2]. In this paper we examine the activity of this complex against MAC in human macrophages, and evaluate its cytotoxicity. MAC-infected macrophages were treated for 24h with free or complexed clofazimine. The in vitro minimum inhibitory concentrations of both free and complexed clofazimine were 0.1 microg/ml. Free and complexed clofazimine inhibited the growth of MAC inside macrophages to a similar extent, while modified cyclodextrin alone had no observable effects on MAC or macrophages. Complexed clofazimine was not toxic to cells at concentrations effective against MAC. The TD(50) of the modified cyclodextrin in THP-1 cell line was 297 microg/ml.

Pioderma gangrenoso: a propósito de un caso controlado con bajas dosis de clofazimina / Pyoderma gangrenosum: report of a case controlled with low dose of clofazimine

Se presenta una paciente de 49 años con pioderma gangrenoso atendida en el Hospital Regional Ushuaia entre 1991 y 1996. Presentó lesiones que comenzaron como nódulos en miembros inferiores y evolucionaron a úlceras necróticas, mostrando distintos cuadros histopatológicos como expresión de una misma enfermedad, sin manifestaciones sistémicas. Fue tratada con clofazimina a bajas dosis con resultado favorable, sin efectos colaterales y sin concurrencia a la fecha (AU)

Pioderma gangrenoso: a propósito de un caso controlado con bajas dosis de clofazimina / Pyoderma gangrenosum: report of a case controlled with low dose of clofazimine

Se presenta una paciente de 49 años con pioderma gangrenoso atendida en el Hospital Regional Ushuaia entre 1991 y 1996. Presentó lesiones que comenzaron como nódulos en miembros inferiores y evolucionaron a úlceras necróticas, mostrando distintos cuadros histopatológicos como expresión de una misma enfermedad, sin manifestaciones sistémicas. Fue tratada con clofazimina a bajas dosis con resultado favorable, sin efectos colaterales y sin concurrencia a la fecha

Pulsed-exposure and postantibiotic leukocyte enhancement effects of amikacin, clarithromycin, clofazimine, and rifampin against intracellular Mycobacterium avium.

We investigated the postantibiotic effects (PAEs) of four agents against Mycobacterium avium in a human macrophage model under two different experimental conditions. For postantibiotic leukocyte enhancement (PALE), bacteria were exposed to antibiotics prior to their phagocytosis, whereas for pulsed exposure (PE), antibiotics were added after phagocytosis. In both cases, the drugs were used at their peak concentrations in serum (Cmax) for 2 h. The results showed two different patterns: one for the drug for which results under PE and PALE test conditions did not significantly differ (amikacin) and one for drugs for which PAE values were significantly higher under PE test conditions (clarithromycin, clofazimine, and rifampin). These data suggest that even a brief exposure of M. avium to peak concentrations of certain drugs in serum may result in prolonged and persistent suppression of bacterial growth inside human macrophages.

Impregnaçäo sui generis conjuntivo-escleral por clofazimina em um paciente portador de hanseníase / Impregnation sui generis of the conjunctiva and sclera by clofazimine in a carrier Hansen's disease

Os autores apresentam o caso de um paciente de 40 anos de idade, portador de hanseníase forma virchoniana que recebeu, por via oral, durante 9 anos, clofazimina, numa dose total de 324 gramas. Apresentou intensa pigmentaçäo na conjuntiva e esclera por este medicamento. A biomicroscopia observavam-se com facilidade cristais policromáticos na conjuntiva e esclera de ombos os olhos. O estudo destes cristais também foi possível à microscopia óptica de fragmento da conjuntiva a fresco. O caso é discutido com os achados na literatura e os autores chamam a atençäo para os diagnóticos diferenciais

Influence of once-monthly rifampicin and daily clofazimine on the pharmacokinetics of dapsone in leprosy patients in Nigeria

In leprosy patients in Nigeria the influence of daily clofazimine and of once-monthly rifampicin on the pharmacokinetics of dapsone has been investigated. Three days after rifampicin the elimination half-life of dapsone was reduced from 40.4 to 25.3 h (n = 23). Correspondingly, the plasma dapsone 24 h after the last dose had fallen significantly from 2.63 to 2.02 mg/l. Clofazimine did not cause change in the pharmacokinetics of dapsone. It was concluded that, although rifampicin had a considerable influence on the pharmacokinetics of dapsone, there is no reason to adjust the dose of dapsone during multidrug therapy of leprosy.