Creep in nitroimidazole inhibitory concentration among the Entamoeba histolytica isolates causing amoebic liver abscess and screening of andrographolide as a repurposing drug.

Infections by Entamoeba histolytica (E. histolytica) lead to considerable morbidity and mortality worldwide and treatment is reliant on a single class of drugs, nitroimidazoles. Treatment failures and intermittent reports of relapse from different parts of world indicate towards development of clinical drug resistance. In the present study, susceptibility testing of clinical isolates of E. histolytica was carried against metronidazole and tinidazole. Additionally, anti-amoebic property of active compounds of Andrographis paniculata was also evaluated. Prevalence of metronidazole resistance gene (nim) in patients attending hospital was also done to get comprehensive insight of present situation of drug resistance in E. histolytica. Mean inhibitory concentration 50 (IC50) value of E. histolytica isolates against metronidazole and tinidazole was 20.01 and 16.1 µM respectively. Andrographolide showed minimum mean IC50 value (3.06 µM). Significant percentage inhibition of E. histolytica isolates by andrographolide was seen as compared to metronidazole (p = 0.0495). None of E. histolytica isolates showed presence of nim gene. However, in stool samples from hospital attending population, prevalence of nimE gene was found to be 76.6% (69/90) and 62.2% (56/90) in diarrheal and non-diarrheal samples respectively. Inhibitory concentration of commonly used nitroimidazoles against clinical isolates of E. histolytica are on rise. Percentage inhibition of E. histolytica isolates by andrographolide was significantly higher than control drug metronidazole.

In Vitro Susceptibility and Resistance of Mycoplasma genitalium to Nitroimidazoles.

Mycoplasma genitalium is a sexually transmitted reproductive tract pathogen of men and women. M. genitalium infections are increasingly difficult to treat due to poor efficacy of doxycycline and acquired resistance to azithromycin and moxifloxacin. A recent clinical trial suggested that metronidazole may improve cure rates for women with pelvic inflammatory disease and reduced the detection of M. genitalium when included with standard doxycycline plus ceftriaxone treatment. As data regarding susceptibility of mycoplasmas to nitroimidazoles are lacking in the scientific literature, we determined the in vitro susceptibility of 10 M. genitalium strains to metronidazole, secnidazole, and tinidazole. MICs ranged from 1.6 to 12.5 µg/mL for metronidazole, 3.1 to 12.5 µg/mL for secnidazole, and 0.8 to 6.3 µg/mL for tinidazole. None of these agents was synergistic with doxycycline in checkerboard broth microdilution assays. Tinidazole was superior to metronidazole and secnidazole in terms of MIC and time-kill kinetics and was bactericidal (>99.9% killing) at concentrations below reported serum concentrations. Mutations associated with nitroimidazole resistance were identified by whole-genome sequencing of spontaneous resistant mutants, suggesting a mechanism for reductive activation of the nitroimidazole prodrug by a predicted NAD(P)H-dependent flavin mononucleotide (FMN) oxidoreductase. The presence of oxygen did not affect MICs of wild-type M. genitalium, but a nitroimidazole-resistant mutant was defective for growth under anaerobic conditions, suggesting that resistant mutants may have a fitness disadvantage in anaerobic genital sites. Clinical studies are needed to determine if nitroimidazoles, especially tinidazole, are effective for eradicating M. genitalium infections in men and women.

Successful Treatment of Persistent 5-Nitroimidazole-Resistant Trichomoniasis With an Extended Course of Oral Secnidazole Plus Intravaginal Boric Acid.

ABSTRACT: We describe a case of persistent 5-nitroimidazole-resistant trichomoniasis cured after 14 days of oral secnidazole and intravaginal boric acid. Secnidazole may be an important treatment option for resistant trichomoniasis, particularly in women who fail other regimens, including higher doses of oral metronidazole and tinidazole for longer durations of time.

In Vitro Testing of Trichomonas vaginalis Drug Susceptibility: Evaluation of Minimal Lethal Concentrations for Metronidazole and Tinidazole That Correspond With Treatment Failure.

BACKGROUND: The only drugs approved by the US Food and Drug Administration for oral treatment of trichomoniasis belong to the 5-nitroimidazole group. Most individuals infected with Trichomonas vaginalis can be cured with a standard treatment of metronidazole or tinidazole, but it is estimated that more than 159,000 people fail treatment each year. Although a minimal lethal concentration (MLC) corresponding to treatment failure has been reported for metronidazole, the MLC for tinidazole associated with treatment failure has not been determined. We conducted a study using T. vaginalis isolates from women with reported treatment success or failure to determine these values. METHODS: We measured MLCs of 47 isolates obtained from women who had failed metronidazole treatment, 33 isolates from women who had failed tinidazole treatment, and 48 isolates from women successfully cured with metronidazole. The cutoff was calculated as the 95th percentile of MLCs of susceptible isolates for each drug. RESULTS: Our data confirmed that the MLC previously associated with metronidazole treatment failure is ≥50 µg/mL and identified the MLC associated with tinidazole treatment failure as ≥6.3 µg/mL. For metronidazole, the agreement between laboratory result and treatment outcome was 93.7%; for tinidazole, this agreement was 88.9%. CONCLUSIONS: The T. vaginalis susceptibility assay is useful for determining whether 5-nitroimidazole treatment failure in persons with trichomoniasis can be attributed to drug resistance. These results are useful for establishing interpretive guidance of test results, and MLC levels can help guide appropriate patient treatment.

Antibiotic resistance status of helicobacter pylori strains isolated from initial eradication patients in Ningbo, China, from 2017 to 2021.

BACKGROUND: Resistance of Helicobacter pylori (H. pylori) to antibiotics is an evolving and dynamic process. Presence of antibiotic resistance impacts the success rate of initial eradication strategies in the clinic. AIM: To improve the success rate of initial eradication therapy and explore new antibiotic regimens, a large sample-based study utilizing antimicrobial susceptibility testing was performed. A total of 2508 H. pylori strains from patients subjected to initial eradication therapy were isolated, cultured, and tested for drug susceptibility from 2017 to 2021. The minimal inhibitory concentration (MIC) was recorded. H. pylori susceptibility profiles and its change trends from initial eradication patients were analyzed. The relationships between drug resistance, year of sample collection, age, and sex of patients were analyzed. RESULTS: The overall resistance rates were as follows: amoxicillin (9.25%), clarithromycin (38.48%), levofloxacin (42.86%), furazolidone (11.28%), doxycycline (8.56%), rifampicin (10.81%), tinidazole (74.32%), gatifloxacin (61.71%), tetracycline (0%), metronidazole (78.71%), ornidazole (97.87%), and fosfomycin (31.67%). Only 38.04% of the strains were pansusceptible to amoxicillin, clarithromycin, levofloxacin, and furazolidone, followed by those of mono resistance (29.90%), double resistance (24.96%), triple resistance (6.34%), and quadruple resistance (0.76%). Significant differences in the resistance rate and MIC were also observed in different age and sex groups. Time of collection and patient age and sex were associated with the distribution of antibiotic resistance. CONCLUSION: With the increasing resistance rate and multiple resistance of H. pylori to commonly used antibiotics, drug susceptibility testing is imperative to permit individualized therapy, and a regimen containing the combination of amoxicillin, furazolidone, tetracycline, doxycycline, or rifampicin is reasonable for initial empirical eradication therapy.

In Vitro Effect of 5-Nitroimidazole Drugs against Trichomonas vaginalis Clinical Isolates.

Infections with the sexually transmitted parasite Trichomonas vaginalis are normally treated with metronidazole, but cure rates are suboptimal and recurrence rates following treatment are high. Therefore, our objective was to assess the in vitro antitrichomonas activities of three other 5-nitroimidazole drugs and compare them with metronidazole. T. vaginalis isolates (n = 94) isolated from South African women presenting with vaginal discharge syndrome at two sexually transmitted disease clinics in KwaZulu-Natal were grown from frozen stock. Twofold serial dilutions (16 to 0.25 mg/L) of metronidazole, tinidazole, ornidazole, and secnidazole were prepared in Diamond's broth. The MICs were read after 48 h of anaerobic incubation at 37°C. An MIC of <2 mg/L was defined as susceptible, an MIC of 2 mg/L was defined as intermediate, and an MIC of >2 mg/L was defined as resistant. Sixty-one percent (57/94) of the T. vaginalis isolates were susceptible to metronidazole, 80% (75/94) were susceptible to tinidazole, 75% (71/94) were susceptible to secnidazole, and 89% (84/94) were susceptible to ornidazole. Resistance levels were 11%, 2%, and 1% for metronidazole, tinidazole, and secnidazole, respectively, while no resistance was observed for ornidazole. Intermediate scores were 28% for metronidazole, 18% for tinidazole, 24% for secnidazole, and 11% for ornidazole. Isolates from a proportion of women with bacterial vaginosis (BV) had higher MICs, and no isolates from women coinfected with another sexually transmitted infectious organism were resistant to any of the antimicrobials tested. This study showed that among T. vaginalis isolates in KwaZulu-Natal, there is no in vitro resistance to ornidazole. Of the 5-nitroimidazoles, metronidazole showed the highest level of resistance. The very low levels of resistance for the other three antimicrobials indicate that all three are viable options as a replacement for metronidazole if these in vitro findings are found to correlate with clinical outcomes. IMPORTANCE Trichomonas vaginalis is the most common nonviral sexually transmitted infection associated with reproductive sequelae and HIV acquisition risk worldwide. Despite its role in reproductive health, a high prevalence in South Africa, and the reported metronidazole resistance worldwide, no alternative regimens have been tested against T. vaginalis in our setting. This study compared the susceptibility patterns of three other 5-nitroiminazoles (secnidazole, tinidazole, and ornidazole), which are active against T. vaginalis with metronidazole in vitro. Metronidazole, the drug of choice for the treatment of trichomoniasis, showed the highest level of resistance, while the three regimens showed very low levels of resistance. These data indicate that all three are viable options as a replacement for metronidazole if these in vitro findings are found to correlate with clinical outcomes.

RP-HPLC-DAD Method Development and Validation for Simultaneous Determination of Lansoprazole, Tinidazole, Amoxicillin, and Naproxen in Their Raw Materials and Combined Dosage Form: DOE Approach for Optimization of the Proposed Method.

BACKGROUND: Helicobacter pylori infection is a common cause of peptic ulcer disease and dyspepsia. In addition, it may result in gastric cancer and gastric mucosa associated lymphoid tissue lymphoma. First-line therapy usually consists of triple therapy containing clarithromycin or amoxicillin, one of the proton pump inhibitors, and metronidazole or tinidazole. In addition to the triple therapy, an analgesic is required to relieve pain such as naproxen. OBJECTIVE: A sensitive and selective method needs to be developed and validated for simultaneous determination of four drugs (amoxacillin, tinidazole, naproxen and lansoprazole), used for treating Helicobacter pylori infection, in their combined dosage forms. METHODS: With the aid of experimental design, the cited drugs were separated and quantified. HPLC with a diode array detector was used and metronidazole, one of the drugs also used for treatment, was the internal standard (IS). A Thermo Scientific BDS Hypersil C18 column (5 µm, 250 mm x 4.6 mm) with mobile phase composed of acetonitrile-water (40 + 60, by volume), pH 5 adjusted with phosphoric acid, at 30°C was used for the separation of the cited drugs. RESULTS: The method was linear over the concentration ranges 10-500 µg/mL for amoxacillin, 10-350 µg/mL for tinidazole, 10-250 µg/mL for naproxen, and 2-20 µg/mL for lansoprazole. The proposed method was fully validated according to International Conference of Harmonization (ICH) guidelines. Statistical analysis revealed no significant difference between the results obtained and the four reference methods for the investigated drugs. CONCLUSION: The method can be easily implemented in QC studies of the cited drugs in their dosage forms. HIGHLIGHTS: Experimental design was applied using Plackett-Burman design for preliminary screening of factors followed by Box-Behnken design for chromatographic method optimization.

Clinical Effect of Clarithromycin Combined with Tinidazole on Helicobacter pylori-Related Gastritis and Its Influence on COX-2 Expression.

Studies have shown that COX-2 expression is upregulated in gastric cancer (GC) as well as in precancerous lesions and in Helicobacter pylori-induced inflammation, suggesting that cyclooxygenase-2 (COX-2) may play an important role in gastric carcinogenesis. We attempted to investigate the role of clarithromycin with tinidazole on Helicobacter pylori-related gastritis from the aspects of clinical effect and COX-2 expression. From January 2016 to January 2019, 130 patients with Helicobacter pylori-related chronic gastritis were collected and grouped into the observation group (OG) and the control group (CG). Altogether, 80 patients in the OG were treated with clarithromycin with tinidazole, while 50 patients in the CG were treated with amoxicillin with metronidazole. Clinical symptom improvement time, content of COX-2 and B cell lymphoma-2 (BCL-2), content of inflammatory factors interleukin-1 (IL-1), IL-4, and C-reactive protein (CRP), expression level of nutritional indicators serum albumin (ALB), realbumin (PA), and transferrin (TF), clearance of Helicobacter pylori, total effective rate, and incidence of adverse reactions were detected. Compared with the CG, the OG had shorter clinical symptom improvement time, lower COX-2 and Bcl-2, lower expression of inflammatory factors IL-1, IL-4, and CRP, higher expression of nutritional indicators ALB, TF, and PA, higher clearance rate of Helicobacter pylori, higher total effective rate, and lower incidence of adverse reactions. Clarithromycin combined with tinidazole can effectively improve the clinical effect of Helicobacter pylori-related gastritis and reduce the expression level of COX-2.

Effects Of Minocycline Combined With Tinidazole For Treatment Of Chronic Periodontitis.

Purpose: To investigate the therapeutic effects of minocycline combined with tinidazole in the treatment of chronic periodontitis (CP). Methods: Seventy-three CP patients treated May 2018­December 2019 at Yuyao People's Hospital (Yuyao, China) were enrolled in this study: 34 were treated with minocycline alone (control group; CG) and 39 were treated with a combination of minocycline and tinidazole (observation group; OG). Both groups were treated continuously for four weeks and plaque index (PLI), bleeding index (BI), periodontal pocket depth (PD), periodontal attachment level (PAL) and alveolar bone height were compared before and after treatment. Pain was evaluated using the visual analogue scale (VAS). Levels of TNF-α and IL-6 before and after treatment were determined using an enzyme-linked immunosorbent assay. Adverse reactions were compared. Results: In each group, PLI, BI, PD, PAL and alveolar bone height were lower after treatment (P<0.05), and those in OG were lower than those in CG (P<0.05). TNF-α and IL-6 levels in both groups were lower after treatment (P<0.05), and the levels in serum of the OG were lower than those of the CG (P<0.05). After treatment, the VAS in OG was lower than that of CG (P<0.05). There was no significant difference in adverse reactions between groups (P>0.05). Conclusion: Minocycline combined with tinidazole was more effective in treating CP than minocycline alone. This drug combination improved the periodontal indexes and inflammatory reaction of CP and relieved their pain. No significant difference in adverse reactions was seen.

Efficacy of two-week therapy with doxycycline-based quadruple regimen versus levofloxacin concomitant regimen for helicobacter pylori infection: a prospective single-center randomized controlled trial.

BACKGROUND: Antibiotic-resistance reduces the efficacy of conventional triple therapy for Helicobacter Pylori infections worldwide, which necessitates using various treatment protocols. We used two protocols, doxycycline-based quadruple regimen and concomitant levofloxacin regimen. The aim was to assess the effectiveness of doxycycline-based quadruple regimen for treating Helicobacter Pylori infections compared with levofloxacin concomitant regimen as empirical first-line therapy based on intention-to-treat (ITT) and per-protocol analyses (PPA) in Syrian population. SETTINGS AND DESIGN: An open-label, randomised, parallel, superiority clinical trial. METHODS: We randomly assigned 78 naïve patients who tested positive for Helicobacter Pylori gastric infection, with a 1:1 ratio to (D-group) which received (bismuth subsalicylate 524 mg four times daily, doxycycline 100 mg, tinidazole 500 mg, and esomeprazole 20 mg, each twice per day for 2 weeks), or (L-group) which received (levofloxacin 500 mg daily, tinidazole 500 mg, amoxicillin 1000 mg, and esomeprazole 20 mg each twice per day for two weeks). We confirmed Helicobacter Pylori eradication by stool antigen test 8 weeks after completing the treatment. RESULTS: Thirty-nine patients were allocated in each group. In the D-group, 38 patients completed the follow-up, 30 patients were cured. While in the L-group, 39 completed the follow-up, 32patients were cured. According to ITT, the eradication rates were 76.92%, and 82.05%, for the D-group and L-group respectively. Odds ratio with 95% confidence interval was 1.371 [0.454-4.146]. According to PPA, the eradication rates were 78.9%, and 82.05% for the D-group and L-group respectively. The odds ratio with 95% confidence interval was 1.219 [0.394-3.774]. We didn't report serious adverse effects. CONCLUSIONS: Levofloxacin concomitant therapy wasn't superior to doxycycline based quadruple therapy. Further researches are required to identify the optimal first-line treatment for Helicobacter-Pylori Infection in the Syrian population. TRIAL REGISTRATION: We registered this study as a standard randomized clinical trial ( Clinicaltrial.gov , identifier- NCT04348786 , date:29-January-2020).

Successful treatment of trichomoniasis with tinidazole following desensitization in a patient allergic to metronidazole.

Metronidazole desensitization is recommended in patients with trichomoniasis and history of an allergic reaction to metronidazole due to presumed cross reactivity with tinidazole and lack of reliably safe and effective alternative therapies. We report our experiences in a patient with persistent trichomoniasis who failed to complete metronidazole desensitization due to a burning sensation over her whole body and pruritus but was later successfully desensitized to tinidazole without experiencing any adverse effects.

Noncandidal vaginitis: a comprehensive approach to diagnosis and management.

Vaginitis is one of the most common causes of patient visits to gynecologists, primary care providers, and urgent care centers. However, many women leave without a clear diagnosis or experience recurrent symptoms despite treatment. The 3 most common etiologies of vaginitis are trichomonas, bacterial vaginosis, and vulvovaginal candidiasis, which account for an estimated 70% of cases. The remaining 30% may be related to other causes of vaginitis, including atrophic vaginitis, desquamative inflammatory vaginitis, and vaginal erosive disease. The purpose of this review is to describe the noncandidal causes of acute and recurrent vaginitis, with the goal of improving the likelihood of accurate diagnosis as well as efficient and effective therapy. We excluded candidal vaginitis from our review because there was a recently published review on this topic in the Journal. The clinical presentation and evaluation of patients with symptoms of vaginitis can be triaged into 1 of 2 diagnostic pathways: noninflammatory and inflammatory vaginitis. The most common noninflammatory cause is bacterial vaginosis. Features such as irritation, purulent discharge, and the presence of polymorphonuclear neutrophils are more suggestive of an inflammatory process. Trichomoniasis is the most common cause of inflammatory vaginitis. Other well-described forms of inflammatory vaginitis include atrophic vaginitis, desquamative inflammatory vaginitis, and erosive disease. We present a review of the pathogenesis, symptoms, examination findings, diagnostic testing, and treatment for each of these causes of noncandidal vaginitis.

Tinidazole efficacy for amebic colitis therapeutic prophylaxis in patients with de novo acute leukemia receiving intensive chemotherapy.

INTRODUCTION: In Mexico, seroprevalence of Entamoeba histolytica is 8.4%. The intestinal amebiasis in patients with acute leukemia of novo, after the start of chemotherapy (CT) in the Hematology Service of the CMN 20 de Noviembre is 12%, even if patients show a negative baseline coprological test. OBJECTIVE: To find out if the administration of tinidazole, in patients with acute leukemia and negative coprological test, at the beginning of the CT, decreases the incidence of amoebic colitis during the induction to remission. METHOD: Prospective and not comparative study. Patients with de novo diagnosis of acute leukemia who initiate induction and initial coprological CT. Tinidazole was indicated, 2 g/day for 5 days in the first week of CT started. They were monitored until the induction was concluded and hematopoietic recovery started. RESULTS: 38 patients, 15 women and 23 men with a mean age of 44 years (16-72), with acute lymphoblastic leukemia 19, myeloblastic 16 and promyelocytic 3. Cases without and with intestinal amebiasis were 35 and 3, respectively. Patients with amebiasis only received tinidazole for 3 days and it was given 2 days after the CT started. CONCLUSION: Tinidazole, in patients with acute de novo leukemia who initiate induction CT, is effective in the prevention of intestinal amebiasis, during the induction stage, if administered at 2 g/day, for five days, starting on day 1 of the CT.

Giardiasis: report of a case refractory to treatment.

Caused by the protozoan Giardia lamblia, giardiasis is one of the most common parasitic diarrheal infections affecting humans. Although a variety of antigiardial drugs are available to treat infections in humans, failure of conventional treatment with nitroimidazoles for giardiasis has been increasingly reported. We describe the follow-up of a patient with recurrent giardiasis refractory to nitroimidazoles. Despite the different therapies received, the symptomatology and parasitic forms of G. lamblia persisted in the patient. There is no standard treatment regimen for giardiasis refractory to nitroimidazoles. When treatment failure is confirmed, it is necessary to switch to second-line regimens.

Therapy of B-ultrasound-guided puncture for incision infection after total abdominal hysterectomy.

OBJECTIVE: This paper aims to investigate the clinical efficacy of B-ultrasound-guided puncture in the treatment of incision infection after total abdominal hysterectomy (TAH) and to provide references for the clinical treatment. PATIENTS AND METHODS: 116 patients with uterine incision infection after TAH were selected and randomly divided into the observation group and the control group, with 58 cases in each group. The patients in the control group received an intravenous drip of ceftazidime and tinidazole to prevent infection, and the patients in the observation group received B-ultrasound-guided puncture treatment on the basis of the treatment plan of the control group. The clinical therapeutic effects between the two groups were compared. RESULTS: The cure rate of excellence in the observation group was 84.48%, and the cure rate in the control group was 53.45%, while the difference between the two groups was statistically significant (p<0.05). The total effective rate in the observation group was 98.28%, and that in the control group was 87.93%, but there was no statistically significant difference between the two groups. The hospital stay was (9.5±1.6) days in the observation group and (12.3±2.1) days in the control group, and the mean hospital stay in the observation group was significantly shorter than that in the control group; the difference between the two groups was statistically significant (p<0.05). CONCLUSIONS: TAH should be performed on patients when they are in the best physical condition, and strictly according to the operation steps to reduce the duration of surgery. The application of B-ultrasound-guided puncture can effectively improve the excellent recovery rate of the incision infection after TAH and shorten the hospitalization time. It is worth popularizing in clinical practice.

[Comparison of the traditional triple and a new bismuth-containing quadruple therapy in the first-line eradication of Helicobacter pylori]. / A Helicobacter pylori-fertozés elso vonalbeli megszüntetésére alkalmazott hagyományos hármas és egy új, bizmuttartalmú négyes kezelés összehasonlítása.

Introduction and aim: As the efficacy of the first-line traditional treatment used to eradicate Helicobacter pylori (H. p.) decreased below 75% in Hungary, a new protocol had to be created. Method: Supposing the success rate of the traditional therapy (14-day double dose of proton pump inhibitor [PPI], 1000 mg amoxicillin b.i.d., 500 mg clarithromycin b.i.d. [PAC]) to be 75% and the efficacy of the new protocol (10-day 120 mg bismuth dicitrate q.i.d., double dose PPI b.i.d., 500 mg tetracycline q.i.d. and 500 mg tinidazole b.i.d. [BQT]) to be 90%, we calculated 109 patients on each arm. Patients were recruited after upper gastrointestinal endoscopy from 5 endoscopic units in Vas county. The heterogeneity of groups, success rate and side effects of both therapies were evaluated by Fisher exact test; p<0.05 was considered significant. Results: 110 patients were included in the BQT and 109 patients in the PAC group. There was no heterogeneity between the two groups in age, gender and indication of eradication. H. p. eradication was successful in 103/110 (93.6%) in the BQT and 81/109 (74.3%) in the PAC group (p<0.001). The odds ratio in the BQT group for successful eradication was 5.05 (95% confidence interval: 2.02-14.42) as compared to the PAC group (p<0.001). The side effects of the two groups were similar, in the BQT group the frequency was 34.5%. Conclusion: 10 day-long BQT containing double dose PPI with 120 mg bismuth dicitrate q.i.d., 500 mg tetracycline q.i.d. and 500 mg tinidazole b.i.d. is recommended as the first-line treatment for the eradication of H. p. because of its high efficacy and tolerable side effects. Orv Hetil. 2019; 160(34): 1340-1345.

Giardiasis: An Overview.

BACKGROUND: Giardiasis is an important cause of waterborne and foodborne diarrhea, daycare center outbreaks, and traveler's diarrhea. OBJECTIVE: The study aimed to provide an update on the evaluation, diagnosis, and treatment of giardiasis. METHODS: A PubMed search was completed in Clinical Queries using the key terms "giardiasis", "Giardia lamblia", "Giardia duodenalis" and "Giardia intestinalis". The search strategy included metaanalyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to the English literature. Patents were searched using the key term "giardiasis" from www.freepatentsonline.com. RESULTS: Giardiasis is caused by the protozoan parasite Giardia lamblia. The parasite is transmitted by the fecal-oral route, frequently through ingestion of contaminated water and food or person-to person transmission. Risk factors for infection include children in day-care settings, child-care workers, institutionalized individuals, travelers in endemic areas, ingestion of contaminated or recreational water, immunodeficiency, cystic fibrosis, and oral-anal sex. Approximately 50 to 75% of infected children are asymptomatic. Other children present acute or chronic diarrhea. Direct fluorescent antibody tests that detect intact organisms, enzyme immunoassays that detect soluble antigens, and multiplex real-time polymerase chain reaction assays that detect specific genes of the parasite in stool samples have improved sensitivity and specificity compared with microscopic examination of stool specimens for the detection of Giardia trophozoites or cysts. Drugs used in the treatment of symptomatic giardiasis are reviewed in this study. Moreover, recent patents related to the management of giardiasis are also discussed. CONCLUSION: Metronidazole, tinidazole, and nitazoxanide are drugs of choice. Resistance to common antigiardial drugs has increased in recent years, therefore, the search for new molecular targets for antigiardial drugs is urgently needed. In general, treatment of asymptomatic carriers is not recommended. Purification of water supply is an important preventive measure.

[Eficacia del tinidazol en la profilaxis terapéutica de la colitis amebiana en pacientes con leucemia aguda de novo que reciben quimioterapia intensiva].

INTRODUCTION: In Mexico, seroprevalence of Entamoeba histolytica is 8.4%. The intestinal amebiasis in patients with acute leukemia of novo, after the start of chemotherapy (CT) in the Hematology Service of the CMN 20 de Noviembre is 12%, even if patients show a negative baseline coprological test. OBJECTIVE: To find out if the administration of tinidazole, in patients with acute leukemia and negative coprological test, at the beginning of the CT, decreases the incidence of amoebic colitis during the induction to remission. METHOD: Prospective and not comparative study. Patients with de novo diagnosis of acute leukemia who initiate induction and initial coprological CT. Tinidazole was indicated, 2 g/day for 5 days in the first week of CT started. They were monitored until the induction was concluded and hematopoietic recovery started. RESULTS: 38 patients, 15 women and 23 men with a mean age of 44 years (16-72), with acute lymphoblastic leukemia 19, myeloblastic 16 and promyelocytic 3. Cases without and with intestinal amebiasis were 35 and 3, respectively. Patients with amebiasis only received tinidazole for 3 days and it was given 2 days after the CT started. CONCLUSION: Tinidazole, in patients with acute de novo leukemia who initiate induction CT, is effective in the prevention of intestinal amebiasis, during the induction stage, if administered at 2 g/day, for five days, starting on day 1 of the CT.

INTRODUCCIÓN: En México la seroprevalencia de la Entamoeba histolytica es del 8.4%. La amebiasis intestinal en pacientes con leucemia aguda de novo posterior al inicio de quimioterapia (QT), en el Servicio de Hematología del CMN 20 de Noviembre, es del 12%, aún si muestran test coprológico negativo basal. OBJETIVO: Averiguar si la administración de tinidazol, en pacientes con leucemia aguda y coprológico negativo, al principio de la QT, disminuye la incidencia de colitis amebiana durante la inducción a la remisión. MÉTODO: Prospectivo y no comparativo. Enfermos con diagnóstico de leucemia aguda de novo que inician QT de inducción y coprológico inicial. Se indicó tinidazol, 2 g/día durante 5 días en la primera semana de comenzada QT. Se vigilaron hasta que la inducción concluyó y se inició la recuperación hematopoyética. RESULTADOS: 38 pacientes, 15 mujeres y 23 hombres con edad media de 44 años (16-72). Con leucemia aguda linfoblástica 19, con mieloblástica 16 y con promielocítica 3. Casos sin y con amebiasis intestinal, 35 y 3, respectivamente. Los pacientes con amebiasis solo recibieron tinidazol durante 3 días y se dio después de 2 días de empezada la QT. CONCLUSIÓN: El tinidazol, en pacientes con leucemia aguda de novo que inician QT de inducción, es efectivo en la prevención de la amebiasis intestinal, durante la etapa de inducción, si se administra a 2 g/día, durante cinco días, a partir del día 1 de la QT.