Amebic abscess of the spleen complicated by metronidazole-induced neurotoxicity: case report

Primary hydatid cyst of the spleen: A rare case report and literature review

Hydatidosis is an endemic disease in certain areas in the world particularly in the Mediterranean, the Middle East, and South America, caused by a cestode known as Echinococcus granulosus. Humans are the accidental intermediate hosts. The liver and the lungs are the most commonly involved organ. If the parasite passes through the pulmonary capillary bed, the hydatid cyst may develop at any site in the body like bone, pancreas, brain, kidney, and orbit. Isolated spleen hydatid cyst is very rare. We hereby report one observation of isolated hydatid cyst of the spleen in a patient living in non-endemic area and without any potential risk.

Garbled speech: a rare presentation of metronidazole-induced neurotoxicity

Neurotoxicity is a rare but significant side effect of metronidazole. We present, here, a case of a 34-year-old man, presenting with garbled speech and word finding difficulty. He was taking metronidazole for the last 3 months for stage 4 decubitus ulcers. MRI of the brain showed abnormal signal intensities in the splenium of the corpus callosum and dentate nuclei of the cerebellum. The diagnosis of metronidazole-induced neurotoxicity was made based on MRI findings. The antibiotic was stopped leading to resolution of abnormal MRI findings. We advocate that metronidazole can be associated with severe neurotoxicity, but its prompt cessation leads to better outcome and prognosis.

Metronidazole induced neurotoxicity in a case of liver abscess

Metronidazole is a commonly used drug and considered relatively safe. But it may present with neurotoxicity, commonly peripheral and rarely central. We report here a case of a young patient with amoebic liver abscess who continued taking metronidazole longer than the prescribed duration of the drug and developed peripheral neuropathy and cerebellar neurotoxicity which was reversible after discontinuation of the drug.

Synthesizing a CuIIcomplex of tinidazole to tune the generation of the nitro radical anion in order to strike a balance between efficacy and toxic side effects

Synthesis, characterization, enzyme assay, DNA binding and antimicrobial activity of a monomeric complex of Cu^IIwith tinidazole: significance of the controlled formation of the nitro radical anion.

Neurologic complications of metronidazole

Metronidazole (Flagyl®) is an antimicrobial agent commonly used in clinical practice. Although it is generally well tolerated with minimal side effects, there are a host of still under-recognized neurologic complications of metronidazole treatment. The following review is aimed at summarizing current literature pertaining to metronidazole-induced neurotoxicity including clinical syndromes, neuroradiological findings, prognosis and proposed pathophysiology. Recognition of the neurotoxic effects of metronidazole is critical as prompt discontinuation is generally associated with full clinical recovery and radiological resolution.

Complications neurologiques du métronidazole. Le métronidazole (Flagyl®) est un agent antimicrobien utilisé couramment en pratique clinique. Bien qu'il soit généralement bien toléré et que ses effets secondaires soient minimes, il existe une myriade de complications neurologiques du traitement par le métronidazole qui ne sont pas toujours reconnues. Le but de cette revue constitue un sommaire de la littérature actuelle concernant la neurotoxicité induite par le métronidazole dont les syndromes cliniques, les constatations neuroradiologiques, le pronostic et l'hypothèse physiopathologique expliquant cette neurotoxicité. Il est important d'identifier ces effets neurotoxiques du métronidazole étant donné que l'arrět immédiat du traitement est généralement associé à une guérison clinique complète et à la disparition des signes radiologiques.

Orofacial dyskinesia associated with the use of levofloxacin

OBJECTIVE

To describe a case of orofacial dyskinesia in a patient treated with levofloxacin for acute diverticulitis.

CASE SUMMARY

A 77-year-old woman with mild renal insufficiency was admitted with acute diverticulitis. She was initiated on levofloxacin 500 mg IV daily and metronidazole 500 mg IV every 8 hours. On day 4 of treatment, she experienced involuntary, rhythmic facial grimacing accompanied by periodic cervical muscular contractures. Her speech became dysarthric, interrupted by uncontrolled facial and tongue movements, all findings consistent with orofacial dyskinesia. Antibiotics were discontinued, and symptoms resolved after administration of diphenhydramine and lorazepam IV.

DISCUSSION

Fluoroquinolone-associated central nervous system (CNS) toxicities are infrequently observed. They are most commonly associated with ciprofloxacin and are thought to be related to inhibition of γ-aminobutyric acid receptors and activation of N-methyl-d-aspartate receptors. Orofacial dyskinesia has previously been reported primarily with second-generation fluoroquinolones, with only a single case report implicating a third-generation fluoroquinolone. To our knowledge, we report the second case of orofacial dyskinesia with a third-generation fluoroquinolone, the first such case associated with levofloxacin. The orofacial dyskinesia experienced in this case was categorized as probably related to levofloxacin, as assessed by the Naranjo adverse drug reaction probability assessment tool. Contributing factors likely included age and renal function.

CONCLUSIONS

Although rare, CNS toxicities such as orofacial dyskinesia have been reported with levofloxacin. Patients on fluoroquinolones of advanced age and with renal insufficiency should be monitored closely for such toxicities.

Metronidazole-induced central nervous system toxicity: a systematic review

OBJECTIVE

To assess patient and medication factors that contribute to metronidazole toxicity.

DATA SOURCES

We searched PUBMED from 1965 through April 7, 2011, and performed a hand search of bibliographies.

STUDY SELECTION

Case reports or case series reporting metronidazole-induced central nervous toxicity.

DATA EXTRACTION

Two authors independently abstracted demographics, metronidazole indication, dose and duration, neurological manifestations, and outcomes as well as brain imaging findings.

DATA SYNTHESIS

Among 64 patients, 48 (77%) had cerebellar dysfunction, 21 (33%) had altered mental status, and 8 (15%) had seizures. Patients' ages averaged 53.3 years (range, 12-87 years), and 64% were male. The median duration of metronidazole was 54 days, although 26% had taken it less than a week and 11% had taken it less than 72 hours. Among cases with outcome data, most patients either improved (n = 18 [29%]) or had complete resolution of their symptoms with discontinuation of metronidazole (n = 41 [65%]). There was no difference in resolution of symptom by age (P = 0.71) or sex (P = 0.34). The patients with cerebellar dysfunction were less likely to experience complete resolution than those with mental status changes or seizures (relative risk, 0.67; 95% confidence interval (CI), 0.49-0.92). Nearly all patients (n = 55 [86%]) underwent imaging of the brain: 44 (69%) underwent magnetic resonance imaging (MRI) and 12 (19%) underwent computed tomographic studies. All patients with cerebellar dysfunction had abnormalities on imaging: 93% (n = 39) had a cerebellar lesion, although numerous areas in the brain were affected. On follow-up MRIs, 25 patients (83%) had complete resolution of abnormalities.

CONCLUSIONS

Metronidazole can rarely cause central nervous system toxicity; it does not seem to be a dose- or duration-related phenomenon. Most patients will have MRI abnormalities. Prognosis is excellent with metronidazole cessation.

Toxic metronidazole-induced MRI changes

OBJECTIVE

To report a case of changes documented by magnetic resonance imaging (MRI) of the head probably due to accumulation of metronidazole in a patient with liver dysfunction.

CASE SUMMARY

A 34-year-old Hispanic man with cirrhosis and hepatitis C being treated with metronidazole for Bacteroides fragilis meningitis and bacteremia developed ataxia, disorientation, and peripheral neuropathy. An MRI at the time meningitis was diagnosed was negative. After the patient received > 60 g of metronidazole, an MRI revealed increased signal intensity below, behind, and lateral to the fourth ventricle. Concomitant metronidazole serum concentration was toxic at 35.1 micrograms/mL.

DISCUSSION

This is the second reported case of metronidazole-induced MRI changes. Metronidazole is known to accumulate in patients with liver dysfunction and can cause peripheral neuropathy and central nervous system (CNS) dysfunction; these effects may take up to two years to completely resolve.

CONCLUSIONS

Metronidazole dosages should be reduced in patients with liver dysfunction to prevent the accumulation of metronidazole, which can lead to CNS dysfunction and peripheral neuropathy.

Amebic liver abscess

Amebiasis is a widespread parasitic disease caused by Entamoeba histolytica. This protozoan organism is the third leading parasitic cause of death in the developing world and is an important health risk to travelers in endemic areas. Amebiasis most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients may develop intestinal invasive disease or extraintestinal disease-amebic liver abscess being the most common extraintestinal manifestation. This article reviews epidemiologic features, pathophysiology, clinical features, diagnostic tests, imaging studies, treatment of amebic liver abscess, and prevention measures.

Metronidazole ototoxicity--report of two cases

Two cases of bilateral moderate to severe sensorineural hearing loss due to oral administration of metronidazole are reported. There has been only one case report of deafness following metronidazole therapy in the world literature. The hearing loss recovered gradually in a period of four to six weeks following withdrawal of drug and oral steroid therapy. The possible mechanism of ototoxicity is discussed. Awareness by the treating physician of ototoxicity due to any drug is stressed.

Convulsions, ataxia and hallucinations following propofol

A 6-year-old fit girl experienced convulsions 44 h after an otherwise uneventful anaesthesia with propofol, alfentanil and nitrous oxide. As an underlying pathology was suspected, the child was kept sedated for 6.5 h for further investigations. During this period she received a continuous infusion of propofol amounting in total to 1600 mg. After having regained consciousness, she was strikingly ataxic and remained so for 5 days. During this period she also experienced two episodes of hallucinations lasting about 2 h. Investigations including lumbar puncture, EEG, cerebral CT and MR scan could not explain the neurological symptoms. She recovered without long-term sequelae.

Protozoa. Amebiasis

The intestinal protozoan parasite Entamoeba histolytica causes amebic dysentery and amebic liver abscess, and ranks third worldwide among parasitic causes of death. The application of molecular techniques to the study of this organism have led to major advances in understanding the pathophysiology of amebic infection. This article reviews what is currently known about the pathogenesis, clinical manifestations, diagnosis, and treatment of amebiasis.

Complementation of an Escherichia coli adhE mutant by the Entamoeba histolytica EhADH2 gene provides a method for the identification of new antiamebic drugs

The pathogenic protozoan parasite Entamoeba histolytica, the cause of amebic dysentery and amebic liver abscess, is an obligate anaerobe, and derives energy from the fermentation of glucose to ethanol with pyruvate and acetyl coenzyme A as intermediates. We have isolated EhADH2, a key enzyme in this pathway, that is a NAD+- and Fe2+-dependent bifunctional enzyme with acetaldehyde dehydrogenase and alcohol dehydrogenase activities. EhADH2 is the only known eukaryotic member of a newly defined family of prokaryotic multifunctional enzymes, which includes the Escherichia coli AdhE enzyme, an enzyme required for anaerobic growth of E. coli. Because of the critical role of EhADH2 in the amebic fermentation pathway and the lack of known eukaryotic homologues of the EhADH2 enzyme, EhADH2 represents a potential target for antiamebic chemotherapy. However, screening of compounds for antiamebic activity is hampered by the cost of large scale growth of Ent. histolytica, and difficulties in quantitating drug efficacy in vitro. To approach this problem, we expressed the EhADH2 gene in a mutant strain of E. coli carrying a deletion of the adhE gene. Expression of EhADH2 restored the ability of the mutant E. coli strain to grow under anaerobic conditions. By screening compounds for the ability to inhibit the anaerobic growth of the E. coli/EhADH2 strain, we have developed a rapid assay for identifying compounds with anti-EhADH2 activity. Using bacteria to bypass the need for parasite culture in the initial screening process for anti-parasitic agents could greatly simplify and reduce the cost of identifying new therapeutic agents effective against parasitic diseases.