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This case report describes seizures and encephalopathy in a nine year-old boy treated with iodoquinol for amebiasis. The toxicity of iodoquinol and other 8-hydroxyquinolines is discussed. The radiopacity of this medication, used worldwide for the treatment of diarrheal illnesses and dermatitis, may be diagnostically useful.
Susceptibility testing was performed on Dientamoeba fragilis ATCC 30948 in a dixenic culture with Klebsiella pneumoniae and Bacteroides vulgatus. D. fragilis was cocultured with the bacteria in TYGM-9 medium (ATCC medium 1171). The activities of antiparasitic drugs were assessed by counting viable D. fragilis trophozoites with a hemacytometer by trypan blue exclusion. The minimal amebicidal concentrations of the following four drugs were determined: iodoquinol at 128 micrograms/ml, paromomycin at 16 micrograms/ml, tetracycline (questionably) at 32 micrograms/ml, and metronidazole at 32 micrograms/ml.
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Blastocystis hominis, an intestinal organism of uncertain taxonomic position, has long been considered nonpathogenic. Some recent studies suggest, however, that it may be associated with diarrhea and may respond to treatment with iodoquinol or metronidazole. To investigate this possibility, we identified 148 persons whose stools contained this organism. Of this number, 32 had at least 6 stool examinations performed. Twenty-seven of the 32 persons were later found to have greater than or equal to 1 recognized pathogens--Entamoeba histolytica, Giardia lamblia or Dientamoeba fragilis--and, after receiving appropriate therapy, became asymptomatic. The B hominis infection, however, was unaffected by therapy. Five persons with only B. hominis infection were treated with iodoquinol without effect; these persons fulfilled the medical criteria for irritable bowel syndrome. We believe that when an apparently symptomatic B. hominis infection responds to therapy, the improvement probably represents elimination of some other undetected organism causing the infection.
Sexual activity is the primary method of transmission for several important parasitic diseases and has resulted in a significant prevalence of enteric parasitic infection among male homosexuals. The majority of parasitic sexually transmitted diseases involve protozoan pathogens; however, nematode and arthropod illnesses are also included in this group. Trichomoniasis, caused by Trichomonas vaginalis, is the most common parasitic STD. Infection with this organism typically results in the signs and symptoms of vaginitis. Trichomoniasis can be diagnosed in the office setting by performing a microscopic evaluation of infected vaginal secretions and can be successfully treated with metronidazole. Both pediculosis pubis, caused by the crab louse Pthirus pubis, and scabies, caused by the itch mite Sarcoptes scabiei, present with severe pruritus. A papular or vesicular rash and linear burrows seen in the finger webs and genital area are characteristic of scabies. Pediculosis pubis is diagnosed by observing adult lice or their nits in areas that bear coarse hair. The diagnosis of scabies is confirmed by scraping suspicious burrows and viewing the mite or its byproducts under the microscope. Lindane, 1% used in treating scabies, is also very effective for treating pediculosis pubis. Synthetic pyrethrins, also applied as a cream or lotion, are less toxic alternatives for the treatment of either condition. Oral-anal and oral-genital sexual practices predispose male homosexuals to infection with many enteric pathogens, including parasitic protozoans and helminths. The most common of these parasitic infections are amebiasis, caused by Entamoeba histolytica, and giardiasis caused by Giardia lamblia. Both entities may cause acute or chronic diarrhea, as well as other abdominal symptoms. Most gay men with amebiasis are asymptomatic, and invasive disease in this group is extremely rare. Both amebiasis and giardiasis can be diagnosed on the basis of microscopic examination of stool specimens, although duodenal aspiration is occasionally necessary to confirm a diagnosis of giardiasis. Multiple treatment regimens exist for amebiasis. Iodoquinol is a good choice for asymptomatic cyst carriers, whereas the combination of metronidazole plus iodoquinol is used for symptomatic patients. Quinacrine and metronidazole are both efficacious in the treatment of giardiasis.
An accurate, sensitive, and selective reversed phase high performance liquid chromatographic (HPLC) method was developed for the analysis of two halogenated 8-hydroxyquinoline derivatives; clioquinol (CQN) and iodoquinol (IQN). The proposed method depends on the complexation ability of the studied compounds with Pd(II) ions. Reversed phase chromatography was conducted using a 300 x 3.9 mm i.d. stainless steel column packed with 10 microm Bondclone phenyl at ambient temperature. A solution containing 0.005% w/v of Pd(II)-chloride in a mixture of acetonitrile-methanol-water (3:3:4 v/v/v) of pH 3.7 as a mobile phase pumped at a flow rate of 0.75 ml min(-1). UV-detection was performed at 282 and 285 nm for CQN and IQN, respectively. The method showed excellent linearity in the range 0.05-1.8 and 0.1-3.0 microg ml(-1) with limit of detection (S/N=2) 4.8 ng ml(-1) (1.57 x 10(-8) M) and 6.4 ng ml(-1) (1.61 x 10(-8) M) for CQN and IQN, respectively. The suggested method was successfully applied for the analysis of the studied drugs in bulk with average% recoveries of 99.68+/-0.44 for CQN and 99.65+/-0.53 for IQN. The proposed method was successfully applied for the analysis of the studied drugs in single or combined dosage forms with average% recoveries of 99.41+/-0.51-100.02+/-0.63. The proposed method could be used successfully for the determination of the studied compounds in the presence of their degradation product as they could be eluted with different retention times. The presence of metronidazole (MNZ) or tolnaftate (TFT) with the studied drugs does not affect their accurate determination. The results obtained were favorably compared with those obtained by the reference method. The results were satisfactorily, accurate, and precise.
Previously a cloned emetine-resistant mutant of the protozoal parasite Entamoeba histolytica was shown to overexpress a gene for an ameba homolog of the mammalian P-glycoprotein, a plasma membrane pump that removes hydrophobic drugs from multidrug-resistant tumor cells. Three sets of experiments were performed to better characterize the multidrug-resistant phenotype of the emetine-resistant amebae. First, the emetine resistance of the mutant amebae was reversed by concentrations of calcium and sodium channel blockers effective in reversing drug resistance by multidrug-resistant tumor cells, but it was reversed only in the presence of very high concentrations of the tricyclic antidepressants. Second, the mutant amebae showed cross-resistance to antiamebic drugs used to treat luminal infection (iodoquinol and diloxanide) but were not cross-resistant to drugs used to treat invasive disease (chloroquine and metronidazole). Third, when amebae were loaded with radiolabeled emetine, the mutant parasites released the drug at approximately 1.6 times the rate of the wild-type organisms. We conclude that the emetine-resistant E. histolytica parasites have some but not all the features of the multidrug-resistant phenotype.
The colon responds monomorphically to a variety of insults thus making it difficult to differentiate invasive amoebic colitis and inflammatory bowel disease (IBD). The authors present a case with chronic dysentery, haematochezia, anaemia and hypoproteinaemia. The endoscopic findings were suggestive of IBD. The stool examination was negative for trophozoites or cysts of parasites. The recto-colonic biopsy specimens showed mucosal inflammation with exudates containing amoebic trophozoites. The patient was successfully treated with metronidazole and iodoquinol. He recovered within two weeks and repeat colonoscopy four weeks after the treatment showed a normal rectum and colon. Clinicians should have a high level of suspicion for amoebic colitis in cases of colitis especially in regions where amoebiasis is still present. Efforts should be made to find the amoebic trophozoites in multiple stool and colonic biopsy specimens.
AIM: To compare the efficacy of antibiotics therapy alone with antibiotics and saccharomyces boulardii in treatment of acute amebiasis. METHODS: In a double blind, random clinical trial on patients with acute intestinal amoebiasis, 57 adult patients with acute amoebiasis, diagnosed with clinical manifestations (acute mucous bloody diarrhea) and amebic trophozoites engulfing RBCs found in stool were enrolled in the study. Regimen 1 included metronidazole (750 mg Tid) and iodoquinol (630 mg Tid) for 10 days. Regimen 2 contained capsules of lyophilized saccharomyces boulardii (250 mg Tid) orally in addition to regimen 1. Patients were re-examined at two and four weeks after the treatment, and stool examination was performed at the end of week 4. Student's t-test, chi(2) and McNemar's tests were used for statistical analysis. RESULTS: Three patients refused to participate. The other 54 patients were randomized to receive either regimen 1 or regimen 2 (Groups 1 and 2 respectively, each with 27 patients). The two groups were similar regarding their age, sex and clinical manifestations. In Group 1, diarrhea lasted 48.0+/-18.5 hours and in Group 2, 12.0+/-3.7 hours (P<0.0001). In Group 1, the durations of fever and abdominal pain were 24.0+/-8.8 and 24.0+/-7.3 hours and in Group 2 they were 12.0+/-5.3 and 12.0+/-3.2 hours, respectively (P<0.001). Duration of headache was similar in both groups. At week 4, amebic cysts were detected in 5 cases (18.5 %) of Group 1 but in none of the Group 2 (P<0.02). CONCLUSION: Adding saccharomyces boulardii to antibiotics in the treatment of acute amebiasis seems to decrease the duration of clinical symptoms and cyst passage.
Several reports have appeared that either support or deny the importance of the protozoan Blastocystis hominis as an intestinal pathogen in humans. In this report, we describe the clinical characteristics of B. hominis and its response to therapy in hospital employees found to have the parasite on routine screening of stools. During the study, 49 patients with B. hominis were identified, and 413 stools were examined from these patients. Twenty-nine patients were asymptomatic (59%), and 20 had symptoms of bloating, flatulence, soft/loose stools, or constipation. Of these 20 patients, 10 had symptoms that correlated with the presence or absence of B. hominis, four had symptoms that were independent of B. homonis, and six had other intestinal parasites that could account for their symptoms. Nineteen percent of patients without treatment had eradication of B. hominis from stool on follow-up examination. Metronidazole did not increase this rate. Iodoquinol treatment eradicated the organism in 41% of patients (p less than 0.05), and resulted in the reduction or eradication of the parasite in 62%, as determined by follow-up examination.
Protozoal infections of the gastrointestinal tract occur worldwide and have substantial morbidity and mortality. Prevalence is higher in the economically deprived regions of the world, especially the developing countries. Infections like amoebiasis and giardiasis have a worldwide distribution, being endemic in India. Apart from producing GI symptoms, growth and development of children is also impaired. It is seen that protozoa multiply rapidly in their hosts and as there is a lack of effective vaccines, chemotherapy has been the only practiced way to treat individuals and reduce transmission. The current treatment modalities for protozoal diarrhoea include 5-nitrosoimidazoles, iodoquinol, diloxanide furoate, paromomycin, chloroquine, and trimethoprim-sulphamethoxazole.
7,7'-Bis(((dimethylamino)carbonyl)oxy)-8,8'-biquinolyl (5) was prepared in 71% yield by regioselective directed ortho metalation (DoM) of N,N-dimethyl O-quinol-7-yl carbamate (2) with LDA followed by oxidation with anhydrous ferric chloride. DoM of 5 with excess LDA induced double anionic ortho-Fries rearrangement and gave 6,6'-bis((dimethylamino)carbonyl)-7,7'-dihydroxy-8,8'-biquinolyl (8). Treatment of N,N-diethyl O-(8-iodoquinol-7-yl) carbamate (16) with LDA in THF solvent at -78 degrees C, followed by addition of anhydrous ferric chloride, resulted in an efficient tandem halogen-dance dimerization process which afforded 7,7'-bis(((diethylamino)carbonyl)oxy)-6,6'-diiodo-8,8'-biquinolyl (17) directly in 54% yield.
The development of an assay to measure the sensitivity of drugs against Blastocystis hominis using the incorporation of 3H-hypoxanthine is described. The activity of 42 compounds have been measured. Four of the 5-nitroimidazoles tested (satranidazole, S75 0400 A, flunidazole and ronidazole) were found to be more active than metronidazole, the drug commonly used to treat infections caused by B. hominis in humans. Other potentially useful compounds include emetine, furazolidone and quinacrine. Ketoconazole and iodoquinol reported to have therapeutic activity in infections caused by this parasite were found to be significantly less active than metronidazole.
BACKGROUND: Dientamoeba fragilis is a rare cause of chronic infectious diarrhea and colitis in children. METHODS: Review of the clinical manifestations, diagnostic methods, and clinical course of D. fragilis infection in our hospital. RESULTS: Eleven pediatric patients are discussed, seven of whom had a history of recent travel. Clinical manifestations of infectious diarrhea included anorexia, intermittent vomiting, abdominal pain, and diarrhea, ranging from 1 to 100 weeks in duration. Peripheral eosinophilia was present in seven patients. One patient with well-documented bovine protein allergy had intermittent episodes of diarrhea and abdominal pain, despite an appropriate elimination diet. Eosinophilic colitis documented by colonoscopy, was due to D. fragilis. Metronidazole was effective in treating five patients, and iodoquinol was effective in treating four others. CONCLUSIONS: D. fragilis should be included in the differential diagnosis of chronic diarrhea and eosinophilic colitis. The identification of this pathogen requires clinical awareness of epidemiologic risk factors and presenting complaints, as well as the laboratory staining procedures essential to its proper identification.
An iodide-miconazole ion-paired complex was used as a suitable ion-exchanger for the preparation of a plasticized-PVC membrane electrode. Among different solvent mediators tested, dioctylsebacate exhibited the proper response characteristics, including Nernstian slope of the calibration curve, fast response time and good reproducibility of the emf values. The electrode exhibits a Nernstian slope of -59.8 +/- 0.5 mV decade(-1) for I- ion over a concentration range of 1.0 x 10(-5) - 1.0 x 10(-2) M with a limit of detection of 7.0 x 10(-6) M. The electrode displays a good selectivity for I- with respect to a number of inorganic and organic species. It canbe used over a pH range of 2.5 - 8.5. The membrane sensor was successfully applied to the determination of iodide in water samples and blood serum, as well as in pharmaceutical products such as iodoquinol and thyroxin.
Family physicians should be alert for unusual diseases in patients who are returning from foreign travel. Malaria is a potentially fatal disease that can be acquired by travelers to certain areas of the world, primarily developing nations. Transmitted through the bite of the Anopheles mosquito, malaria usually presents with fever and a vague systemic illness. The disease is diagnosed by demonstration of Plasmodium organisms on a specially prepared blood film. Travelers can also acquire amebic infections, which may cause dysentery or, in some instances, liver abscess. Amebiasis is diagnosed by finding Entamoeba histolytica cysts or trophozoites in the stool. Invasive amebic infections are generally treated with metronidazole followed by iodoquinol or paromomycin. Cutaneous larva migrans is acquired by skin contact with hookworm larvae in the soil. The infection is characterized by the development of itchy papules followed by serpiginous or linear streaks. Cutaneous larva migrans is treated with invermectin or albendazole. Case studies are presented.
Dientamoeba fragilis is a pathogenic protozoan parasite with a world-wide distribution. Although originally described as an amoeboid organism, it has been reclassified as a flagellate, on the basis of a number of electron microscopic and immunological findings. Except for its lack of a flagellum, D. fragilis closely resembles Histomonas and Trichomonas. Interestingly, a resistant cyst stage has not been demonstrated and it is unlikely that its trophozoites can survive successfully outside the human host. As a consequence of its higher than anticipated coincidence of infection with Enterobius vermicularis, transmission may occur via ova of this pinworm. D. fragilis infection may be acute or chronic, and has been reported in both children and adults. The most common clinical symptoms include abdominal pain, persistent diarrhoea, loss of appetite, weight loss and flatulence. Occasionally, eosinophilia, urticaria and pruritus have been described. Demonstration of the characteristic nuclear structure of D. fragilis, needed for a definitive diagnosis, cannot be achieved in unstained faecal material; therefore, permanently stained smears are essential. Treatment is recommended in symptomatic cases, and iodoquinol, tetracycline and metronidazole have been used successfully.
Invasive amoebiasis is rarely seen in human immunodeficiency virus (HIV)-infected individuals, even in endemic areas. By contrast, cytomegalovirus (CMV) disease is recognized as a major clinical problem in acquired immunodeficiency syndrome patients. A 34-year-old HIV-infected man with amoeba colitis, disseminated Mycobacterium avian complex and CMV infection with cecum perforation, presented with the initial symptoms of fever, shortness of breath and painful sensation when swallowing. He was treated with fluconazole, trimethoprim-sulfamethoxazole and hydrocortisone under the impression of esophageal candidiasis and Pneumocystis jiroveci pneumonia. However, diarrhea and abdominal pain developed on day 6 of hospitalization. Invasive amoebiasis and CMV colitis was diagnosed after examination of colon pathological specimens. Emergent laparotomy was performed. Right hemicolectomy with double barrel ileostomy and colostomy was done due to perforation of the cecum. Iodoquinol was given, followed by metronidazole 14 days afterwards. He underwent closure of double barrel ileostomy and colostomy 5 months later. This case illustrates the diagnostic challenge of caring for acquired immunodeficiency syndrome persons with multiple illnesses and medication use. CMV infection, amoebic colitis and possibly corticosteroid may have played a role in colon perforation in our patient.