Acute metronidazole-induced neurotoxicity: an update on MRI findings

Drugs with a negative impact on cognitive functions (part 3): antibacterial agents in patients with chronic kidney disease

The relationship between chronic kidney disease (CKD) and cognitive function has received increased attention in recent years. Antibacterial agents (ABs) represent a critical component of therapy regimens in patients with CKD due to increased susceptibility to infections. Following our reviewing work on the neurocognitive impact of long-term medications in patients with CKD, we propose to focus on AB-induced direct and indirect consequences on cognitive function. Patients with CKD are predisposed to adverse drug reactions (ADRs) due to altered drug pharmacokinetics, glomerular filtration decline, and the potential disruption of the blood-brain barrier. ABs have been identified as a major cause of ADRs in vulnerable patient populations. This review examines the direct neurotoxic effects of AB classes (e.g. beta-lactams, fluoroquinolones, aminoglycosides, and metronidazole) on the central nervous system (CNS) in patients with CKD. We will mainly focus on the acute effects on the CNS associated with AB since they are the most extensively studied effects in CKD patients. Moreover, the review describes the modulation of the gut microbiota by ABs, potentially influencing CNS symptoms. The intricate brain-gut-kidney axis emerges as a pivotal focus, revealing the interplay between microbiota alterations induced by ABs and CNS manifestations in patients with CKD. The prevalence of antibiotic-associated encephalopathy in patients with CKD undergoing intravenous AB therapy supports the use of therapeutic drug monitoring for ABs to reduce the number and seriousness of ADRs in this patient population. In conclusion, elucidating AB-induced cognitive effects in patients with CKD demands a comprehensive understanding and tailored therapeutic strategies that account for altered pharmacokinetics and the brain-gut-kidney axis.

Antibiotic-induced neurological adverse drug reactions

Antibiotics are drugs widely used all around the world. Central nervous system adverse drug reactions (CNS ADRs) are mostly under-suspected with antibiotics. Nevertheless, these ADRs could lead to severe complications such as encephalopathy. To illustrate the clinical patterns of these off-target ADRs, we here present data from pharmacovigilance system, through different populations and points of view (worldwide, French population, vulnerable population and individual). These data could help clinicians to better know about CNS ADRs with antibiotics, to better identify risk factors and vulnerable patients and to highlight the importance to set up the right diagnostic explorations in the best timing to avoid complications. Clinicians should request a pharmacological opinion from pharmacologist (biologists and pharmacovigilance clinicians) in front of vulnerable population before or during antibiotics. Pharmacovigilance advice could help clinicians in the diagnosis and the management of an ADR. Therapeutic drug monitoring is particularly contributive to adjust doses of antibiotics administered in vulnerable patients. Pharmacovigilance advice and TDM are essential to perform personalized medicine, and contribute to the proper use of drugs.

Metronidazole-Induced Acute Cerebellitis in a Young Patient: Unusual Onset, Delayed Remission, and Characteristic Imaging Features

Metronidazole-induced acute cerebellitis is an exceptionally rare condition resulting from severe adverse reactions to metronidazole, a medication generally employed in the management of infections caused by anaerobic microbes. Although neuropathy has been linked to metronidazole use, reports of acute cerebellitis are infrequent. The neurological effects associated with metronidazole can include weakness, dysarthria, postural instability, seizures, giddiness, vertigo, ataxia, confusion, encephalopathy, headaches, and tremors. The onset of cerebellitis can vary, occurring as early as one day or after several weeks of metronidazole treatment. This article presents a case of a young girl who presented to us with weakness in both upper and lower limbs, dysarthria, and postural instability after exposure to 12 grams of metronidazole (suicidal, 30 tablets of 400 mg). With the above-mentioned complaints, the patient was advised of magnetic resonance imaging of the brain, which showed the features of cerebellitis.

Drugs with a negative impact on cognitive functions (Part 2): drug classes to consider while prescribing in CKD patients

There is growing evidence that chronic kidney disease (CKD) is an independent risk factor for cognitive impairment, especially due to vascular damage, blood-brain barrier disruption and uremic toxins. Given the presence of multiple comorbidities, the medication regimen of CKD patients often becomes very complex. Several medications such as psychotropic agents, drugs with anticholinergic properties, GABAergic drugs, opioids, corticosteroids, antibiotics and others have been linked to negative effects on cognition. These drugs are frequently included in the treatment regimen of CKD patients. The first review of this series described how CKD could represent a risk factor for adverse drug reactions affecting the central nervous system. This second review will describe some of the most common medications associated with cognitive impairment (in the general population and in CKD) and describe their effects.

Metronidazole prescribing practices in Australian hospitals: Measuring guideline compliance and appropriateness to support antimicrobial stewardship

BACKGROUND

Metronidazole is a commonly prescribed antimicrobial in Australian hospitals. Inappropriate use may increase risks to patient care, such as toxicities and antimicrobial resistance. To date, there is limited information on the quality of metronidazole prescriptions to inform antimicrobial stewardship and quality improvement initiatives. This study aims to describe the quality of metronidazole prescribing practices in Australian hospitals.

METHODS

Retrospective data analysis of the Hospital National Antimicrobial Prescribing Survey (Hospital NAPS). Data were collected by auditors at each participating hospital using a standardised auditing tool. All data from 2013 to 2021 were de-identified and analysed descriptively. Variables included were antimicrobial prescribed, indication, guideline compliance and appropriateness.

RESULTS

Metronidazole was the fifth most prescribed antimicrobial in the Hospital NAPS dataset (2013-2021), accounting for 5.7 % (n = 14,197) of all antimicrobial prescriptions (n = 250,863). The proportion of metronidazole prescriptions declined by 2 % from 2013 to 2021 (p < 0.001). The most common indications were surgical prophylaxis (15.3 %), diverticulitis (9.4 %), aspiration pneumonia (7.3 %). Over half (53.5 %) of metronidazole prescriptions were deemed compliant with prescribing guidelines and 67.8 % were deemed appropriate. These rates were comparatively lower than the overall results of all antimicrobials. The primary documented reason for inappropriateness was that the spectrum was too broad (34.2 %). Surgical prophylaxis had the lowest rates of guideline compliance (53.8 %) and appropriateness (54.3 %).

CONCLUSIONS

Metronidazole remains widely used in Australian hospitals with suboptimal rates of guideline compliance and appropriateness. A noted area for improvement that we identified was using metronidazole when its spectrum was too broad, possibly when anaerobic therapy is unnecessary. With increasing international adoption of the Hospital NAPS programme, future comparative studies will be critical to identify global trends of antimicrobial prescribing quality. Antimicrobial stewardship (AMS) programmes have proven to be effective in improving prescribing quality and should be considered to specifically target improvements in metronidazole prescribing.

Metronidazole-induced encephalopathy delayed diagnosis due to cerebellar infarction: A case report

RATIONALE

Metronidazole is a 5-nitroimidazole antibiotic effective against anaerobic bacterial and parasitic infections. Long-term use may cause side effects in the central nervous system, although the occurrence of encephalopathy is rare.

PATIENT CONCERNS

A 73-year-old man was diagnosed with acute pyelonephritis and received antibiotic treatment. During the treatment, the patient complained of back pain. Lumbar spinal magnetic resonance imaging (MRI) revealed infective spondylitis, and metronidazole (1.5 g) was administered daily for approximately 160 days. The patient developed cognitive dysfunction and gait disorder after antibiotic treatment, and brain MRI showed acute infarction in both cerebellar lobes. Secondary prevention with antiplatelet and physiotherapy was prescribed; however, functional recovery was not achieved.

DIAGNOSIS

After 1 month, a follow-up brain MRI showed high signal intensity and diffusion restriction in the corpus callosum on diffusion-weighted images and high signal intensity in the dentate nucleus on T2-weighted images. Therefore, metronidazole-induced encephalopathy was suspected.

INTERVENTIONS

Metronidazole was discontinued, and ceftriaxone (2 g/day) was administered to manage the infective spondylitis.

OUTCOMES

One week after the discontinuation of the drug, the patient's cognition improved to the extent that communication was possible. Thus, even if other neurological deficits, such as cerebellar infarction, are found in patients with long-term disability, the possibility of metronidazole-induced encephalopathy should be considered when metronidazole is used for a long time.

Diffuse subcortical white matter restriction: An uncommon finding on metronidazole toxicity

Metronidazole is a common and widely used antibiotic to treat a wide range of infectious diseases and has been associated with serious neurologic disturbances which in some cases were irreversible. We present a metronidazole-induced encephalopathy in a 19-year-old girl after 7 days of metronidazole treatment, with diffusion restricted subcortical white matter lesions along with the corpus callosum involvements. Diverse clinical presentation of a serious neurologic disturbance caused by a common widely used antibiotic should be carefully addressed in the setting of both short- and long-term treatment.

Metronidazole induced cerebellar toxicity after prolonged treatment of large multiloculated pyogenic liver abscess; A case report and literature review

Metronidazole is a common antibiotic agent for hepatic abscesses, which require both gram-negative and anaerobic coverage. Rarely, this antibiotic has been found to induce encephalopathy. Here, we describe a 65-year-old male who was treated with metronidazole for his hepatic abscess, who presented with syncope and questionable seizure and was found to have magnetic resonance imaging (MRI) brain findings consistent with metronidazole toxicity. Our patient demonstrated striking brain MRI findings which can be used to further understand the process behind this medication-induced toxicity. Hypotheses of this mechanism include swelling of axons secondary to increased water or vasospasm leading to reversible ischemia that is localized in the brain. In terms of MRI findings, brain lesions tend to populate bilaterally with focus at the dorsal pons, midbrain, cerebellar dentate nuclei (as with our patient), dorsal medulla, or splenium of corpus callosum. Additional research is warranted regarding this rare manifestation and timely removal of the offending agent is crucial for reversal of symptoms.

Metronidazole-Induced Encephalopathy in a 16-Year-Old Girl with Crohn’s Disease: Case Report and Review of the Pediatric Literature

Metronidazole-induced encephalopathy (MIE) is a rare and unpredictable complication that is most commonly reported in adults. Here, we present the case of MIE in a patient treated with rectal, oral, and intravenous metronidazole. This is the first case of MIE reported after suppositories. A 16-year-old girl with Crohn’s disease treated with mesalazine and exclusive enteral nutrition was operated on due to perianal fistulas and abscesses. She received oral metronidazole for 25 days and rectal metronidazole for 15 days as an adjuvant before surgery. Moreover, 2.5 g of intravenous metronidazole was administrated during the perioperative period. The second day after the surgery, symptoms of cerebellar syndrome appeared. She presented with an inability to coordinate balance and gait. Although she showed accurate verbal responses, her speech was slow, slurred, and scanning. The finger–nose test was positive. The T2-weighted magnetic resonance imaging revealed an increased symmetrical signal within the dentate nuclei of the cerebellum and in the corpus callosum. The changes were characterized by restricted diffusion. Based on the clinical picture and magnetic resonance imaging findings, MIE was diagnosed. Treatment with metronidazole was discontinued. The cumulative dose of metronidazole that she received for 29 days was 54 g: 38 g p.o., 13.5 g p.r., and 2.5 g i,v. The first symptoms appeared on the 28th day of antibiotic therapy after receiving 52 g of metronidazole. The neurological symptoms resolved after six days; however, three days after the resolution, paresthesia appeared in the distal phalanges of both feet and lasted for approximately two months. Our report highlights that neurologic symptoms related to metronidazole treatment should raise the suspicion of MIE.

S, Siddiqui SA, Gupta A, Pathak V, Mulani M, Khan S, Bansal T. MRI Findings and Topographic Distribution of Lesions in Metronidazole-Induced Encephalopathy

Purpose

This study aims to describe the magnetic resonance imaging (MRI) of the brain of five patients diagnosed with metronidazole-induced encephalopathy (MIE). In addition, the aim of our study was to better define the topographic distribution of lesions in MIE.

Methods

We retrospectively evaluated MRI findings before and after drug cessation in five patients diagnosed with MIE at Era’s Lucknow Medical College and Hospital, Lucknow, Uttar Pradesh, India. The main MRI signal changes and lesion locations were studied.

Results

Among the patients observed, the average age of the patients with MIE was 55 years (range: 30-70 years). Cerebellar dysfunction, mainly ataxia, and altered mental status were seen in the majority of cases. The most frequently involved sites were the dentate nucleus (cerebellum), brain stem, and corpus callosum (splenium). In diffusion-weighted imaging (DWI), most lesions did not show true restricted diffusion, except for a solitary corpus callosum lesion.

Conclusion

Although drug-related side effects are more common with long-term use of metronidazole, they may also occur with high doses for short durations. The dentate nucleus, the splenium in the corpus callosum, and the brain stem are the most affected structures. Apart from a solitary lesion of the corpus callosum, all identified lesions were reversible at follow-up MRI after discontinuation of metronidazole. The clinical presentation and characteristic MRI changes are highly specific and can be correlated to make a rapid and more accurate diagnosis of this potentially treatable condition. Prognosis is excellent if detected early.

A Rare Case of Metronidazole Overdose Causing Ventricular Fibrillation

Ventricular fibrillation is not known as a complication of metronidazole poisoning. Although some arrhythmias have been reported as a complication of metronidazole intake while taking antiarrhythmic medications, most such arrhythmias are possibly related to co-ingestion of drugs with metronidazole as it affects the metabolism of these drugs. In this case, ventricular fibrillation occurred in a young patient without preexisting medical conditions or any other known drug ingestion, which was never been reported before.

We present a case of an 18-year-old male brought in by the ambulance service after attempting to end his life by overdosing on metronidazole. While being transported he developed ventricular fibrillation and received an electric shock, which reverted the episode. Laboratory investigations did not show any clear cause that might have precipitated his arrhythmia.

Metronidazole-Induced Toxic Neuropathy With the "Boomerang" Sign: A Case Report

BACKGROUND

Metronidazole has been used to treat a broad range of infections over the decades, and its safety profile has been presumably well studied. However, neurological severe adverse events after prescription and nonprescription use of metronidazole is well recognized but underdiagnosed.

CASE PRESENTATION

We report the case of a 48-year-old Indian man who presented with unremitting symptoms of peripheral neuropathy along with a silent callosal lesion in the splenium ("boomerang" sign). Because he had visited 3 neurologists previously, there were many targeted and nontargeted investigations, which failed to reach an etiological diagnosis and hence to provide relief. The patient was questioned about a potential neurotoxin exposure, and at this point, he said that he was taking metronidazole for a long time, without any supervision, as an over-the-counter remedy for self-diagnosed "chronic amebiasis." On stopping metronidazole, he recovered gradually. In the sixth month of follow-up, brain magnetic resonance imaging showed disappearance of the callosal lesion and significant improvement in the nerve conduction studies.

CONCLUSIONS

Clinicians should keep metronidazole toxicity in mind while dealing with a case of cytotoxic lesion of the corpus callosum with splenium involvement and peripheral neuropathy.

Imaging of Dentate Nucleus Pathologies: A Case Series

The dentate nucleus is the largest cerebellar nucleus, and it controls cognition and voluntary movement. It is found in each cerebellar hemisphere medially and posterolateral to the lateral ventricle. Pathologies of the dentate nucleus can be detected using computed tomography and magnetic resonance imaging of the brain. Here, we present a case series of seven different dentate nucleus diseases and their neuroimaging findings recovered from archives of our institution.

Reusable Ag@TiO2-Based Photocatalytic Nanocomposite Membranes for Solar Degradation of Contaminants of Emerging Concern

Two significant limitations of using TiO2 nanoparticles for water treatment applications are reduced photocatalytic activity under visible radiation and difficulty recovering the particles after use. In this study, round-shaped Ag@TiO2 nanocomposites with a ≈21 nm diameter and a bandgap energy of 2.8 eV were synthesised by a deposition-precipitation method. These nanocomposites were immobilised into a porous poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) matrix and well-distributed within the pores. The photocatalytic activity of Ag@TiO2/PVDF-HFP against metronidazole (MNZ) under solar radiation was evaluated. Further, an adaptive neuro-fuzzy inference system (ANFIS) was applied to predict the effect of four independent variables, including initial pollutant concentration, pH, light irradiation intensity, and reaction time, on the photocatalytic performance of the composite membrane on MNZ degradation. The 10% Ag@TiO2/PVDF-HFP composite membrane showed a maximum removal efficiency of 100% after 5 h under solar radiation. After three use cycles, this efficiency remained practically constant, demonstrating the membranes' reusability and suitability for water remediation applications.

Metronidazole-induced reversible cerebellar dysfunction

A 73-year-old man who presented with fever and abdominal discomfort was diagnosed to have a liver abscess. He was treated with antimicrobials which included metronidazole. One month into treatment, he developed neurological symptoms and signs that were suggestive of cerebellar pathology. MRI of the brain showed T2/fluid attenuated inversion recovery hyperintensities involving bilateral dentate, fastigial and interpositus nuclei. After excluding common aetiologies, the possibility of metronidazole-induced neurotoxicity was considered. After stopping metronidazole, his symptoms and signs resolved. A subsequent MRI scan of the brain showed reversal of changes. Neurotoxicity caused by metronidazole is an uncommon adverse effect of a commonly used antimicrobial drug and should be considered in the appropriate clinical scenario.

Antibiomania: A Rare Case of Metronidazole-Induced Mania

Metronidazole is a very commonly used drug for the treatment of ailments caused by bacteria and parasites. It can treat a vast array of conditions like rosacea, sexually transmitted diseases (STDs), liver abscess, bedsores, etc. Metronidazole comes with generic side-effects like nausea, vomiting, dizziness, metallic taste, and also rare side-effects like paresthesia, syncope, cerebellar symptoms, psychosis but mania is a rare side-effect. Here, we present a case of metronidazole induced mania in a 50-year-old male with no past medical history who initially presented with a complaint of mild fever, loss of appetite, and fatigue from the past 10-12 days. On further examination and investigations, diagnosis of the amebic liver abscess was made on the basis of USG, serum serology for amebiasis IgG, and a CT scan. Consequently, the patient was started on the drug of choice for amebic liver abscess; IV metronidazole 1.5g/day divided over the day into three doses. Other drugs that were administered were pantoprazole, paracetamol, and ondansetron. On the ninth day of admission, the patient's wife as well as the physician-daughter of the patient reported a change in the behavior of the patient which became a major concern for the family. The patient was restless, energetic, unable to sleep, had racing thoughts, elated mood, petulant, and kept singing loudly in the private patient room. There was no history of any psychiatric illness in the family. Mr. K´s manic symptoms were managed using haloperidol and lorazepam. Upon discontinuing metronidazole, there was a gradual improvement in the manic symptoms, and symptoms improved, haloperidol and lorazepam were able to be tapered down and eventually stopped. Mr. K did not require any use of any selective serotonin reuptake inhibitor (SSRIs), monoamine oxidase inhibitors (MAOIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), or any other atypical psychotropic drug. Manic-psychosis side-effect is a rare entity caused by antibiotics and the symptoms of which would disappear in a few days after stopping the antibiotic. It is also notable that this patient recovered without the use of any psychotropic drugs. Physicians should be aware of the possible neuropsychiatric side-effects of antibiotics which can lead to unnecessary workup. This side-effect did not require the use of any psychotropic drugs in this patient.