2-Hydroxymethyl-1-methyl-5-nitroimidazole, one siderophore inhibitor, occludes quorum sensing in Pseudomonas aeruginosa.

Siderophore is necessary for the survival of microorganisms and is interregulated with quorum sensing (QS) systems. It is related to growth, proliferation, virulence, and other bacterial social activities as a virulence factor. Thus, we speculated that the QS system could be occluded by inhibiting siderophore production. 2-Hydroxymethyl-1-methyl-5-nitroimidazole (HMMN), one siderophore inhibitor of Pseudomonas aeruginosa PAO1 (P. aeruginosa PAO1), was obtained by using the Chromeazurol S (CAS) method. We found that HMMN inhibited siderophore production and influenced the biological effects of QS regulation, including biofilm formation and pyocyanin production. HMMN (150 µg/ml) inhibited the siderophore production of P. aeruginosa PAO1 by 69.37%. In addition, HMMN could inhibit pyocyanin production and biofilm formation and erase the formed biofilm of P. aeruginosa PAO1. HMMN (150 µg/ml) inhibited the biofilm formation of P. aeruginosa PAO1 by 28.24%. The erasure rate of the formed biofilm reached 17.03%. Furthermore, HMMN (150 µg/ml) inhibited P. aeruginosa PAO1 pyocyanin production by 36.06%. Meanwhile, positive-control hordenine (500.0 µg/ml) reduced the biofilm formation and pyocyanin production of P. aeruginosa PAO1 by 14.42% and 34.35%, respectively. The erasure rate of hordenine to the formed biofilm is 11.05% at 500 µg/ml. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that HMMN downregulates not only siderophore-related genes but also QS-related genes, as well as hordenine. These results suggest that a siderophore inhibitor could be used as a QS inhibitor to occlude the QS system and reduce virulence.

Secnidazole: a treatment for trichomoniasis in adolescents and adults.

INTRODUCTION: Single-dose 2-g oral secnidazole (SEC), newly approved by the U.S. Food and Drug administration (FDA) for treatment of trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various micro-organisms. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other FDA-approved treatments for trichomoniasis in the United States - metronidazole and tinidazole - SEC has favorable pharmacokinetics, including a longer half-life and a lower minimal lethal concentration. AREAS COVERED: This work summarizes the chemistry and pharmacology of SEC and reviews the evidence on its efficacy, tolerability, and safety for the treatment of trichomoniasis. EXPERT OPINION: SEC is an efficacious, well tolerated, and safe treatment for patients aged ≥12 years with trichomoniasis. Single-dose administration makes it a favorable treatment option, especially in cases where adherence to multi-dose treatment regimens may be low.

Secnidazole for Trichomoniasis in Women and Men.

INTRODUCTION: Secnidazole (SEC), newly FDA-approved for trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various infections. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other approved treatments for trichomoniasis in the U.S.-metronidazole and tinidazole-SEC has favorable pharmacokinetics, including a longer half-life, and a lower minimal lethal concentration against Trichomonas vaginalis. OBJECTIVES: Provide an updated, comprehensive review of the literature evaluating SEC as a treatment for trichomoniasis in women and men. METHODS: We conducted a search to identify existing research on SEC and trichomoniasis. On August 6, 2021, we searched MEDLINE using the terms "secnidazole" and "trichomon.*" We excluded reviews, editorials, case reports, and small case series. RESULTS: We identified 29 articles; 14 of which were included: 5 reported in vitro pharmacologic data on SEC, 6 were observational studies, and 4 were controlled clinical trials (1 observational study also reported in vitro pharmacologic data). Six studies reported data on women only, 1 on men only, and 3 on women and men. These studies showed that SEC-as a single dose or 3-day course-had comparable efficacy to multi-dose metronidazole for treating trichomoniasis in women and men, was generally well tolerated by patients, and had a favorable pharmacokinetic profile. A single 2-g dose of SEC also led to a microbiologic cure rate of 92.2% in the first randomized, double-blind, placebo-controlled study of trichomonas-infected US-based women. CONCLUSION: SEC is an efficacious and safe treatment for women and men with trichomoniasis. Single-dose administration makes it a favorable treatment option for patients, especially in cases where adherence to other multi-dose treatment regimens could be problematic. Christina A. Muzny and Olivia T. Van Gerwen. Secnidazole for Trichomoniasis in Women and Men. Sex Med Rev 2022;10:255-262.

Biology-oriented drug synthesis and evaluation of secnidazole esters as novel enzyme inhibitors.

The identification of novel compounds that can inhibit physiologically and metabolically important drug targets or enzymes has prime importance in medicinal chemistry. With this aim, a range of secnidazole esters 1-30 were synthesized under the heading of biology-oriented drug synthesis by the 1,1'-carbonyldiimidazole-mediated coupling reaction between secnidazole and varyingly benzoic acid derivatives. All compounds were screened for inhibitory activity against human carbonic anhydrase (hCA) I and II, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase. The results indicate that all the synthesized compounds showed potent inhibitory activities against all targets, as compared to the standard inhibitors, revealed by IC50 values. Ki values of the secnidazole derivatives 1-30 for hCA I, hCA II, AChE, BChE, and α-glucosidase enzymes were obtained in the ranges of 47.37-190.74, 44.38-198.21, 12.14-68.37, 8.04-61.53, and 7.78-45.91 nM, respectively. To assess the enzyme-ligand interactions, the optimized most active compounds 2, 3, 8, 9, 14, 17, and 23 were subjected to molecular docking studies with modeled AChE, BChE, hCA I, hCA II, and α-glucosidase enzymes, where several important and key interactions were monitored with amino acid residues of each target enzyme.

Rapid Determination of Metronidazole and 2-Hydroxymetronidazole in Murine Blood Plasma.

Metronidazole is a drug used to treat bacterial and protozoan infections. Nowadays, it is one of the most frequently prescribed drugs worldwide. The main aim of this paper is to present a rapid, reliable and simple high-performance liquid chromatography (HPLC) method to determine metronidazole along with its primary metabolite, 2-hydroxymetronidazole, in plasma or serum using paracetamol as an internal standard. A total of 100% methanol was used to denature plasma proteins. After centrifugation, the supernatant was evaporated under nitrogen flow. The samples were dissolved in the mobile phase and injected into a Li-Chrospher RP-18 column. A total of 10 mmol/L NaH2PO4: acetonitrile (90:10, v/v) solution with a flow rate of 1 mL/min was used as the mobile phase. Metronidazole and 2-hydroxymetronidazole were detected at two different wavelengths at 320 nm and 311 nm, respectively. The method is characterized by high precision (relative standard deviation % < 6). The method was used for the determination of metronidazole and 2-hydroxymetronidazole in murine blood using small amounts of plasma (≤100 µL).

Successful treatment with secnidazole for trichomoniasis in the setting of metronidazole hypersensitivity.

Limited effective treatment options currently exist for trichomoniasis management among patients with metronidazole hypersensitivity. We report a patient with a documented history of metronidazole hypersensitivity who initially was treated with nitazoxanide but demonstrated clinical and microbiological failure. Secnidazole was subsequently used for treatment, which resulted in clinical and microbiological cure without observation of cross-reactivity. Secnidazole may represent a potential treatment option for trichomoniasis in patients with metronidazole hypersensitivity after consultation with an infectious disease specialist.

Efficacy and Safety of Single Oral Dosing of Secnidazole for Trichomoniasis in Women: Results of a Phase 3, Randomized, Double-Blind, Placebo-Controlled, Delayed-Treatment Study.

BACKGROUND: Trichomonas vaginalis is the most prevalent nonviral sexually transmitted infection. We evaluated the efficacy and safety of secnidazole vs placebo in women with trichomoniasis. METHODS: Women with trichomoniasis, confirmed by a positive T. vaginalis culture, were randomized to single-dose oral secnidazole 2 g or placebo. The primary endpoint was microbiological test of cure (TOC) by culture 6-12 days after dosing. At the TOC visit, participants were given the opposite treatment. They were followed for resolution of infection afterward and offered treatment at subsequent visits, if needed. Fifty patients per group (N = 100) provided approximately 95% power to detect a statistically significant difference between treatment groups. RESULTS: Between April 2019 and March 2020, 147 women enrolled at 10 sites in the United States. The modified intention-to-treat (mITT) population included 131 randomized patients (secnidazole, n = 64; placebo, n = 67). Cure rates were significantly higher in the secnidazole vs placebo group for the mITT population (92.2% [95% confidence interval {CI}: 82.7%-97.4%] vs 1.5% [95% CI: .0%-8.0%]) and for the per-protocol population (94.9% [95% CI: 85.9%-98.9%] vs 1.7% [95% CI: .0%-8.9%]). Cure rates were 100% (4/4) in women with human immunodeficiency virus (HIV) and 95.2% (20/21) in women with bacterial vaginosis (BV). Secnidazole was generally well tolerated. The most frequently reported treatment-emergent adverse events (TEAEs) were vulvovaginal candidiasis and nausea (each 2.7%). No serious TEAEs were observed. CONCLUSIONS: A single oral 2 g dose of secnidazole was associated with significantly higher microbiological cure rates vs placebo, supporting a role for secnidazole in treating women with trichomoniasis, including those with HIV and/or BV. CLINICAL TRIALS REGISTRATION: NCT03935217.

The immunomodulatory activity of secnidazole-nitazoxanide in a murine cryptosporidiosis model.

Introduction. Cryptosporidium parvum causes intestinal parasitic infections affecting both immunosuppressed and immunocompetent individuals.Gap statement. Given the absence of effective treatments for cryptosporidiosis, especially in immunodeficient patients, the present study was designed to assess the therapeutic efficacy of secnidazole (SEC) and its combination with nitazoxanide (NTZ) in comparison to single NTZ treatment in relation to the immune status of a murine model of C. parvum infection.Methodology. The infected groups were administered NTZ, SEC or NTZ-SEC for three or five successive doses. At days 10 and 12 post-infection (p.i.), the mice were sacrificed, and the efficacy of the applied drugs was evaluated by comparing the histopathological alterations in ileum and measuring the T helper Th1 (interferon gamma; IFN-γ), Th2 [interleukin (IL)-4 and IL-10] and Th17 (IL-17) cytokine profiles in serum.Results. The NTZ-SEC combination recorded the maximal reduction of C. parvum oocyst shedding, endogenous stages count and intestinal histopathology, regardless of the immune status of the infected mice. The efficacy of NTZ-SEC was dependent on the period of administration, as the 5 day-based treatment protocol was also more effective than the 3 day-based one in terms of immunocompetence and immunosuppression. The present treatment schedule induced an immunomodulatory effect from SEC that developed a protective immune response against C. parvum infection with reduced production of serum IL-17, IFN-γ, IL-4 and IL-10.Conclusions. Application of NTZ-SEC combined therapy may be useful in treatment of C. parvum, especially in cases involving immunosuppression.

Derivatisation of metronidazole enhances cytotoxic effect against Acanthamoeba genotype T4 isolates and leads to cytomorphological changes in trophozoites.

Amoebae of the genus Acanthamoeba are worldwide distributed causative agents of serious human infections such as granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). To date, treatment of these infections is non-uniform and frequently unsuccessful. Recently, the phosphonium salts were studied for their high levels of antimicrobial activity. This work was aimed to investigate the cytotoxic effect of metronidazole and two phosphonium salts (PS1, PS2) on two clinical Acanthamoeba isolates. The isolates showed distinctly higher susceptibility to both phosphonium salts than to metronidazole. The highest susceptibility was noted to PS1 after 48 h of incubation. Metronidazole derivate PS2 showed higher susceptibility than metronidazole. The values of EC50 of PS2 were approximately twenty times lower than EC50 of metronidazole for Acanthamoeba lugdunensis strain and sixteen times lower for Acanthamoeba quina strain after 48 h. Although the therapeutic effect of metronidazole in Acanthamoeba infections is usually insufficient, its derivatisation can result in a significantly higher amoebicidal effect. Cytomorphological changes of trophozoites after exposure to tested compounds included rounding up of the cells, damage of membrane integrity, presence of pathological protrusions, elongation of the cells or pseudocyst-like stages. Obtained results indicate possible therapeutic potential of studied phosphonium salts.

Thermosensitive hydrogels for vaginal delivery of secnidazole as an approach to overcome the systemic side-effects of oral preparations.

Secnidazole (SEC) has been suggested as an alternative agent against Trichomonas vaginalis to overcome the adverse effects, antimicrobial resistance problems and poor adherence to the currently available therapy. Once no topical formulation may be found in the market until now, SEC was incorporated in thermosensitive bioadhesive systems to extend the contact time in the mucosa and to avoid a systemic drug disposition. Formulations containing 20% poloxamer 407, 1% poloxamer 188 and 1 or 2.5% chitosan showed suitable sol-gel transition temperature (> 30 °C), presenting a fast gelation time (100-115 s). Rheological, dynamic light scattering and infrared spectroscopy analysis suggested molecular interactions among polymers. Chitosan increased the mucoadhesion strength of the formulations. In addition, hydrogels showed a tendency to decrease the drug transport rate through mucosa when compared to the control. Mucin was also added onto mucosa for a more realistic simulation of permeability/retention. In the presence of this agent, hydrogels containing chitosan reduced the permeability/retention of the drug in approximately 2.0-fold when compared to the control. Therefore, the hydrogels presented suitable characteristics to remain in the vaginal environment, which would result in effective local treatment of trichomoniasis.

Transition Metal Chelation Augments the Half-life of Secnidazole: Molecular Docking and Fluorescence Spectroscopic Approaches.

This current research aimed to establish the most required pharmacodynamics parameters of two transition metal complexes of an antimicrobial drug secnidazole. The spectroscopic fluorescence quenching strategy was outlined to evaluate the binding mechanism and binding affinity of nickel (II) and chromium (III) complexes of secnidazole with bovine serum albumin (BSA). The conformational modifications and the interacting patterns of the protein due to the interaction of the parent compound of the metal complexes have been investigated by molecular docking approach. The ligand-protein interactions were confirmed by the spectral quelling of the serum protein's intensity in the presence of metal chelate of secnidazole. The quenching mechanism was an endothermic dynamic process. The calculated thermodynamic factors delineated van der Waals interactions mainly influenced the spontaneous process. The UV-fluorescence curves were studied to establish the energy transformation profile according to the Förster resonance energy transfer (FRET) theory. The double-logarithm plot exhibited the binding number that ensured the drug-protein interaction was at a 1:1 ratio. The compared binding constants dictated that both metal chelates gained higher binding affinity, longer half-life, and achieved the capacity to show the pharmacological effects by a lower dose than the parent molecule.

In vitro metabolic profile and drug-drug interaction assessment of secnidazole, a high-dose 5-nitroimidazole antibiotic for the treatment of bacterial vaginosis.

A single-dose oral granule formulation of secnidazole 2 g (SOLOSEC™ ) has been approved in the US as a treatment for bacterial vaginosis. Available data on the likelihood of in vitro drug-drug and alcohol-drug interactions are limited. Secnidazole was incubated with cultured human hepatocytes over a range of concentrations (0-10 000 µmol/L) to assess metabolic profiling. Cytochrome P450 (CYP) and aldehyde dehydrogenase inhibition over a similar concentration range were evaluated in human liver microsomes (HLMs) or recombinant enzymes using competition or time-dependent inactivation assays. Secnidazole exhibited very low metabolism in HLMs at concentrations up to 6400 µmol/L. Secnidazole was found to be metabolized to a limited extent predominantly by CYP3A4 and CYP3A5 among a panel of cDNA-expressed enzymes. Secnidazole inhibited CYP2C19 and CYP3A4, with IC50 values of 3873 and 3722 µmol/L, respectively. Secnidazole did not exhibit time-dependent inhibition. There was no inhibition (IC50 value >5000 µmol/L) observed for any other CYP enzyme or with human recombinant aldehyde dehydrogenase 2 (ALDH2). These results are the first reported observation of the metabolism and drug-drug interaction profile for secnidazole and demonstrate that the agent has minimal to no potential drug interactions of concern.

An Integrated Efficacy and Safety Analysis of Single-Dose Secnidazole 2 g in the Treatment of Bacterial Vaginosis.

Bacterial vaginosis (BV) is the most common gynecologic infection in women aged 14 to 49 years. Currently recommended treatments require extended dosing and are thus associated with poor adherence. A single-dose oral granule formulation of secnidazole 2 g (SOLOSEC™ [secnidazole], Symbiomix Therapeutics, a Lupin company, Baltimore, MD), a 5-nitroimidazole antibiotic with antimicrobial activity, has been approved by the US Food and Drug Administration for the treatment of BV in adult women. As part of the US registration package, two randomized, double-blind, placebo-controlled clinical studies were conducted to confirm the efficacy and safety of a novel single-dose oral formulation of secnidazole 2 g. This is an integrated analysis of efficacy and safety results from these studies, pivotal study 1 and pivotal study 2. By combining the results of the two studies, relevant information is presented especially when considering the effect of secnidazole on patients with recurrent episodes of BV and the difference in effect on patients of black race. Single-dose secnidazole 2 g was statistically superior to placebo on all primary and secondary efficacy outcomes in both trials, including clinical outcome responder rate (P < 0.001), achievement of Nugent scores in the normal range of 0 to 3 (P < 0.001), greater numbers of patients as therapeutic outcome responders at the test of cure/end of study visit on days 21-30 (P < 0.001), and fewer patients requiring additional treatment at the test of cure/end of study visit (P < 0.001), supporting the role for single oral dose secnidazole 2 g granules as treatment for women with BV.

Metronidazole and Secnidazole Carbamates: Synthesis, Antiprotozoal Activity, and Molecular Dynamics Studies.

We prepared a series of 10 carbamates derivatives based on two common antiprotozoal drugs: metronidazole (1-5) and secnidazole (6-10). The compounds were tested in vitro against a set of two amitochondriate protozoa: Giardia duodenalis and Trichomonas vaginalis. Compounds 1-10 showed strong antiprotozoal activities, with potency values in the low micromolar-to-nanomolar range, being more active than their parent drugs. Metronidazole carbamate (1) was the most active of the series, with nanomolar activities against G. duodenalis (IC50 = 460 nM) and T. vaginalis (IC50 = 60 nM). The potency of compound 1 was 10 times greater than that of metronidazole against both parasites. None of compounds showed in vitro cytotoxicity against VERO cells tested at 100 µM. Molecular dynamics of compounds 1-10, secnidazole, and metronidazole onto the ligand binding site of pyruvate-ferredoxin oxidoreductase of T. vaginalis and the modeled -tubulin of G. duodenalis revealed putative molecular interactions with key residues in the binding site of both proteins implicated in the mode of action of the parent drugs.

5-Nitroimidazole refractory giardiasis is common in Matanzas, Cuba and effectively treated by secnidazole plus high-dose mebendazole or quinacrine: a prospective observational cohort study.

OBJECTIVE: To evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis. METHOD: Adults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed. RESULTS: A total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated. CONCLUSIONS: 5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting.

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.

HPLC Determination of Imidazoles with Variant Anti-Infective Activity in Their Dosage Forms and Human Plasma.

A suitable HPLC method has been selected and validated for rapid simultaneous separation and determination of four imidazole anti-infective drugs, secnidazole, omeprazole, albendazole, and fenbendazole, in their final dosage forms, in addition to human plasma within 5 min. The method suitability was derived from the superiority of using the environmentally benign solvent, methanol over acetonitrile as a mobile phase component in respect of safety issues and migration times. Separation of the four anti-infective drugs was performed on a Thermo Scientific® BDS Hypersil C8 column (5 µm, 2.50 × 4.60 mm) using a mobile phase consist of MeOH: 0.025 M KH2PO4 (70:30, v/v) adjusted to pH 3.20 with ortho-phosphoric acid at room temperature. The flow rate was 1.00 mL/min and maximum absorption was measured with UV detector set at 300 nm. Limits of detection were reported to be 0.41, 0.13, 0.18, and 0.15 µg/mL for secnidazole, omeprazole, albendazole, and fenbendazole, respectively, showing a high degree of the method sensitivity. The method of analysis was validated according to Food and Drug Administration (FDA)guidelines for the determination of the drugs, either in their dosage forms with highly precise recoveries, or clinically in human plasma, especially regarding pharmacokinetic and bioequivalence studies.

Fact versus Fiction: a Review of the Evidence behind Alcohol and Antibiotic Interactions.

Many antibiotics carry caution stickers that warn against alcohol consumption. Data regarding concurrent use are sparse. An awareness of data that address this common clinical scenario is important so health care professionals can make informed clinical decisions and address questions in an evidence-based manner. The purpose of this systematic review was to determine the evidence behind alcohol warnings issued for many common antimicrobials. The search was conducted from inception of each database to 2018 using PubMed, Medline via Ovid, and Embase. It included studies that involved interactions, effects on efficacy, and toxicity/adverse drug reactions (ADR) due to concomitant alcohol consumption and antimicrobials. All interactions were considered in terms of three components: (i) alteration in pharmacokinetics/pharmacodynamics (PK/PD) of antimicrobials and/or alcohol, (ii) change in antimicrobial efficacy, and (iii) development of toxicity/ADR. Available data support that oral penicillins, cefdinir, cefpodoxime, fluoroquinolones, azithromycin, tetracycline, nitrofurantoin, secnidazole, tinidazole, and fluconazole can be safely used with concomitant alcohol consumption. Data are equivocal for trimethoprim-sulfamethoxazole. Erythromycin may have reduced efficacy with alcohol consumption, and doxycycline may have reduced efficacy in chronic alcoholism. Alcohol low in tyramine may be consumed with oxazolidinones. The disulfiram-like reaction, though classically associated with metronidazole, occurs with uncertain frequency and with varied severity. Cephalosporins with a methylthiotetrazole (MTT) side chain or a methylthiodioxotriazine (MTDT) ring, ketoconazole, and griseofulvin have an increased risk of a disulfiram-like reaction. Alcohol and antimicrobial interactions are often lacking evidence. This review questions common beliefs due to poor, often conflicting data and identifies important knowledge gaps.

Secnidazole for treatment of bacterial vaginosis: a systematic review.

BACKGROUND: Bacterial vaginosis (BV) is one of the common vaginal infections among childbearing women. The usual treatment for BV is metronidazole; hence 30% of women have recurrence within 60 to 90 days after treatment. There are some studies which assessed the effect of secnidazole on BV. The aim of this systematic review was to investigate the effectiveness of secnidazole for treatment of BV. METHODS: The Cochrane Library, MEDLINE (PubMed), Scopus, and Web of Science (all databases from inception till October 28, 2018) were searched. Primary outcomes were clinical cure rate and microbiologic cure rate and the secondary outcomes were adverse events. Data was extracted from eligible studies by two review authors individually and analyzed by RevMan 5.3. RESULTS: Our search found six trials involving 1528 participants. Treatment with 2 g secnidazole could significantly reduce the risk of BV in patients with three or less episodes of BV in the last year by OR: 7.54 (95% CI, 3.89-14.60, p < 0.00001) and in patients with four or more episodes of BV in the last year (OR: 4.74, 95% CI: 1.51-14.84, p = 0.0.008). Secnidazole (2 g) could significantly increase the microbiologic cure rate in women with 3 or less episodes of BV in the last year (OR: 7.63, 95% CI: 2.30-25.33, p = 0.0009) but not in the women with 4 or more episodes of BV in the last year (OR: 20.17, 95% CI: 1.06-382.45, p = 0.05). The clinical cure rate, microbiological effect and the therapeutic cure rate of 2 g secnidazole was significantly more than that of 1 g secnidazole. The results showed that the clinical cure rate of 2 g secnidazole was not different from the following medications: metronidazole (500 mg bid for 5 days), secnidazole plus vaginal metronidazole, 2 g single dose of oral metronidazole and 2 g secnidazole plus vaginal ornidazole. CONCLUSION: This review showed that 2 g and 1 g secnidazole were better than placebo, however, 2 g secnidazole was more effective than 1 g. Secnidazole 2 g was not different from metronidazole (500 mg bid for 5 days), or from secnidazole plus vaginal metronidazole, or 2 g single dose of oral metronidazole or from 2 g secnidazole plus vaginal ornidazole.

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.