A case of multiorgan failure due to carbamazepine intoxication successfully treated with multimodal blood purification therapy

Carbamazepine (CBZ) intoxication can occur due to various factors, including drug interactions and over-ingestion. Extracorporeal elimination, particularly through hemodialysis and hemoperfusion, is effective in treating severe carbamazepine intoxication. However, as the effectiveness of various modalities can differ, method selection may be based on a specific clinical situation. A 47-year-old woman who took CBZ for schizophrenia presented to our hospital with episodes of vomiting and consciousness disorder. As the CBZ concentration was > 20 μg/mL, she was admitted to the intensive care unit with a diagnosis of acute CBZ poisoning. She underwent one session of hemoperfusion for 2 h, and her CBZ level decreased from > 20 µg/mL to 6.4 µg/mL. However, she developed acute kidney and liver injuries 2 days after admission and underwent intermittent hemodialysis, plasma exchange, continuous hemodiafiltration (CHDF), and online HDF, depending on her condition. Her general condition improved, and she was transferred to the psychiatric department. To our knowledge, no case reports have described severe acute CBZ poisoning in a patient who developed multiorgan failure to date, which was successfully treated with multimodal blood purification therapy. When treating severe CBZ intoxication, blood purification therapy should be tailored to the changing pathophysiology of the condition.

Hyperammonemia syndrome in immunosuppressed individuals

PURPOSE OF REVIEW

Hyperammonemia syndrome is an increasingly recognized and often fatal condition that occurs in immunosuppressed individuals, most commonly lung transplant recipients. Growing evidence suggests hyperammonemia syndrome is associated with systemic infections caused by urease-producing organisms, namely Ureaplasma spp., an organism unable to grow with routine culturing techniques. This review will summarize the epidemiology and clinical manifestations of hyperammonemia syndrome, as well as diagnostic and management strategies once hyperammonemia syndrome is suspected.

RECENT FINDINGS

Hyperammonemia syndrome is being described in increasing frequency in the solid organ transplant population. Morbidity and mortality, even with treatment, is high once hyperammonemia syndrome occurs. Surveillance studies indicate the prevalence of lung donor colonization with Ureaplasma spp. is high, suggesting screening and treatment may be of benefit. Antibiotic resistance is common, and rapid diagnostics can facilitate appropriate antimicrobial therapy in the peri-transplant period.

SUMMARY

Hyperammonemia syndrome is most commonly seen in lung transplant recipients and has a high mortality rate once it occurs. Screening for Ureaplasma spp. should be considered in all lung transplant donors.

Extrahepatic portosystemic shunts as an unusual but treatable cause of hyperammonemic encephalopathy in a noncirrhotic patient - a case report

We report a case of hyperammonemic encephalopathy due to extrahepatic portosystemic shunts in a noncirrhotic patient. A 79-year-old woman suffered from episodic confusion, disorientation, dysphasia and fluctuating level of consciousness. Electroencephalography (EEG) showed encephalopathic changes and serum levels of ammonia were elevated. Further investigation revealed mesenterorenal and mesenterocaval shunts, which had possibly evolved after pancreatic surgery 5 years ago. After shunt obliteration, the symptoms completely resolved, ammonia levels dropped to the normal range and EEG findings normalized. Clinicians should be aware of this rare but treatable cause of encephalopathy in noncirrhotic patients.

Phenylamine/Amide Grafted in Silica as Sensing Nanocomposites for the Removal of Carbamazepine: A DFT Approach

This study aimed to remove carbamazepine from aqueous solutions, using functional silica phenylamine (SiBN), which is characterized and showed excellent chemical and thermal stability. Adsorbents based on silica were developed due to their unusually large surface area, homogenous pore structure, and well-modified surface properties, as silica sparked tremendous interest. It was determined to develop a novel silica adsorbent including phenylamine and amide (SiBCON). The adsorbents obtained were analyzed by various spectroscopy devices, including SEM, FT-IR and TGA analysis. The maximum removal rates for carbamazepine were 98.37% and 98.22% for SiBN and SiBCON, respectively, when optimized at room temperature, pH 9.0, initial concentration of 10 mg·L−1 and contact time of 15 min. Theoretical tools are widely used in the prediction of the power of interactions between chemical systems. The computed data showed that new amine modified silica is quite effective in terms of the removal of carbamazepine from aqueous solution. Calculation binding energies and DFT data showed that there is a powerful interaction between amine-modified silica and carbamazepine.

LC–MS3 Strategy for Quantification of Carbamazepine in Human Plasma and Its Application in Therapeutic Drug Monitoring

This study developed a detection method based on the strategy of HPLC/MS³ and verified its suitability by quantifying carbamazepine in human plasma. The high-performance liquid chromatography–tandem mass spectrometry (HPLC/MS³) system was performed using a Shimadzu UFLC XR liquid chromatography and a SCIEX QTRAP^® 5500 linear ion trap triple quadrupole mass spectrometer. The specific operation was as follows: the sample protein was firstly precipitated using methanol, then carbamazepine and carbamazepine-D₂N¹⁵ were separated on an ACQUITY UPLC HSS T3 column using the gradient elution with solvent A (0.1% formic acid) and solvent B (0.1% formic acid in acetonitrile) at a flow rate of 0.25 mL/min. Each sample was run for 7 min. This method was validated for various parameters including accuracy, precision, selectivity, linearity, LLOQ, etc. Only 5 μL of sample plasma could obtain the result of LLOD 0.5 µg/mL. The intra-day and inter-day precision was <8.23%, and accuracy was between −1.74% and 2.92%. This method was successfully used for monitoring the blood concentration of epilepsy patients after carbamazepine treatment.

Hyperammonaemic Encephalopathy Caused by Adult-Onset Ornithine Transcarbamylase Deficiency

Hyperammonaemic encephalopathy in adults is a rare condition in the absence of liver disease and is associated with a high mortality and risk of permanent neurological deficits. Seldomly, the condition is caused by an inborn error of metabolism in the urea cycle, triggered by an exogenic factor such as gastrointestinal haemorrhage, gastric bypass surgery, starvation, seizures, vigorous exercise, burn injuries, or drugs hampering the elimination of ammonia. Here, we present a fatal case of an unrecognized genetic ornithine transcarbamylase deficiency (OTCD) presenting with a subacute progressive encephalopathy. We review the current literature and discuss the differential diagnosis and treatment options. As swift diagnosis and initiation of treatment is vital, awareness of hyperammonaemic encephalopathy and its possible causes can help improve the prognosis of this condition.

Hyperammonemia syndrome associated with Ureaplasma spp. Infections in immunocompromised patients and transplant recipients: A systematic review and meta-analysis

BACKGROUND

Hyperammonemia syndrome (HS) is reported to occur in patients with Ureaplasma spp. infections. We performed a systematic review and meta-analysis of studies reporting HS in patients with Ureaplasma spp. infection.

METHODS

We searched several databases (CINAHL, OVID, ProQuest, and Scopus) from inception to January 2021. We described case reports and series, and performed a meta-analysis for all cohort studies. The pooled risk ratio (RR) for the association between HS and Ureaplasma spp. infections was derived using a random-effects model.

RESULTS

The systematic review yielded 18 studies. HS was reported in 53 patients with Ureaplasma spp. infections. The most common clinical manifestations were neurologic. Meta-analysis showed a higher incidence of HS (41.67%) and peak ammonia concentration among Ureaplasma spp.-infected lung transplant recipients compared with Ureaplasma spp.-negative recipients (2.84%). The risk of HS was significantly increased in Ureaplasma spp.-infected recipients compared with Ureaplasma spp.-negative recipients (RR: 14.64; CI: 2.85-75.24). Mortality from Ureaplasma-associated HS was 27.27% compared with 5.24% in those with HS from other causes.

CONCLUSIONS

The risk of developing HS is higher among Ureaplasma-infected patients compared with uninfected patients. Lung transplant recipients appear to be disproportionally affected, and HS should be suspected in those who present with neurologic symptoms.

Serum Levels of Valproic Acid and Carbamazepine Do Not Correlate Well with End-Organ Dysfunction

BACKGROUND

Serum levels of anticonvulsants are commonly ordered; however, the clinical utility of these laboratory tests is unclear. Clarifying the significance of anticonvulsant drug levels is essential to allow physicians to make appropriate management decisions. We aimed to determine to what extent elevated serum levels of valproic acid (VPA) and carbamazepine (CBZ) correlate with laboratory indications of end-organ dysfunction.

METHODS

We reviewed a consecutive sample of patients 0-18 years of age who, over a 2-year period, had at least one blood collection in which (1) serum [VPA] or [CBZ] was tested; and (2) at least one of the following tests was performed: alanine aminotransferase (ALT), aspartate aminotransferase (AST), platelets, white blood cells (WBC), ammonia, sodium.

RESULTS

913 and 300 blood collections met criteria for VPA and CBZ, respectively. A slight increased frequency of having any abnormal laboratory value for elevated [VPA] compared to low/normal [VPA] was observed (p = 0.02; relative risk 1.27), while there was no difference in frequency of having any abnormal lab value for CBZ, nor were there significant differences for the individual lab values. When ALT and AST were plotted against [VPA] and [CBZ], no significant correlation was observed.

CONCLUSION

Serum [VPA] and [CBZ] are poor indicators of risk for drug-induced end-organ dysfunction. There are likely other, individualized risk factors that explain why certain patients develop adverse effects from these medications.

Noncirrhotic hyperammonemia: A factor behind dementia to alter mental status

Healthcare givers were recommended to check serum ammonia level for elderly patients with acute-on-chronic alteration of mental status. Early initiation of antihyperammonemia therapy may benefit improvement of alteration of mental status. Baseline mental status becomes necessary for diagnose the acute alteration of mental status and monitor the therapeutic process.

Hyperammonemia and lactic acidosis in adults: Differential diagnoses with a focus on inborn errors of metabolism

The adult endocrinologist may be asked to consult on a patient for unexplained biochemical disturbances that could be caused by an underlying inborn error of metabolism. A genetic disorder is generally less likely to be the cause as these disorders are individually rare, however inborn errors of metabolism are collectively not infrequent and important to consider as they may be treatable and tragic outcomes avoided. Hyperammonemia or lactic acidosis are most often secondary markers of an acquired primary disease process, but they may be a clue to the presence of a genetic disorder. Herein is presented an approach to the differential diagnosis of elevated ammonia and lactate, and a brief discussion of management for when an inborn error is diagnosed.

Hyperammonaemia and associated factors in unprovoked convulsive seizures: A cross-sectional study

PURPOSE

Hyperammonaemia is frequently observed in patients who have experienced convulsive seizures. Although excessive muscle contraction is presumed to be responsible for the elevated levels of ammonia, the underlying mechanism is poorly understood. The present study aimed to identify the independent factors associated with ammonia elevation using large-scale multivariate analysis.

METHODS

We conducted a cross-sectional study involving 379 adult patients who had been transported to our emergency department and treated for unprovoked convulsive seizures between August 2010 and September 2015. Elevation of venous plasma ammonia levels was set as the primary endpoint, and patients' clinical and laboratory data were obtained. Those with severe liver dysfunction, known hepatic encephalopathy, or convulsions due to cardiovascular or psychogenic causes, and those taking valproate were excluded.

RESULTS

Using a cut-off value of 50μg/dL, 183 patients (48.3%) were found to have elevated levels of plasma ammonia. Four factors were identified as independent variables associated with hyperammonaemia following seizures: elevated venous lactate, lowered venous pH, sex (male), and longer duration of convulsion.

CONCLUSIONS

The results of the present study revealed independent factors associated with hyperammonaemia following unprovoked convulsive seizures in a larger scale and with more plausible statistical analysis. The authors further suggest that the excessive skeletal muscle contraction and/or respiratory failure during/after convulsive seizure may be the primary mechanism of hyperammonaemia.

The outcome of agitation in poisoned patients in an Iranian tertiary care university hospital

Introduction. This study was conducted to evaluate and document the frequency and causes of agitation, the symptoms accompanying this condition in intoxications, relationship between agitation score on admission and different variables, and the outcome of therapy in a tertiary care referral poisoning center in Iran. Methods. In this prospective observational study which was done in 2012, 3010 patients were screened for agitation at the time of admission using the Richmond Agitation Sedation Scale. Demographic data including age, gender, and the drug ingested were also recorded. The patients' outcome was categorized as recovery without complications, recovery with complications (hyperthermia, renal failure, and other causes), and death. Results. Agitation was observed in 56 patients (males, n = 41), mostly aged 19–40 years (n = 38) and more frequently in illegal substance (stimulants, opioids and also alcohol) abusers. Agitation score was not significantly related to the age, gender, and previous history of psychiatric disorders. Forty nine patients had recovery without any complication. The need for mechanical ventilation was the most frequent complication. None of the patients died. Conclusion. Drug abuse seems to be a must-to-consider etiology for patients presenting with acute agitation and its morbidity and mortality could be low in agitated poisoning cases if prompt supportive care is performed.

Ammonia metabolism and hyperammonemic disorders

Human adults produce around 1000 mmol of ammonia daily. Some is reutilized in biosynthesis. The remainder is waste and neurotoxic. Eventually most is excreted in urine as urea, together with ammonia used as a buffer. In extrahepatic tissues, ammonia is incorporated into nontoxic glutamine and released into blood. Large amounts are metabolized by the kidneys and small intestine. In the intestine, this yields ammonia, which is sequestered in portal blood and transported to the liver for ureagenesis, and citrulline, which is converted to arginine by the kidneys. The amazing developments in NMR imaging and spectroscopy and molecular biology have confirmed concepts derived from early studies in animals and cell cultures. The processes involved are exquisitely tuned. When they are faulty, ammonia accumulates. Severe acute hyperammonemia causes a rapidly progressive, often fatal, encephalopathy with brain edema. Chronic milder hyperammonemia causes a neuropsychiatric illness. Survivors of severe neonatal hyperammonemia have structural brain damage. Proposed explanations for brain edema are an increase in astrocyte osmolality, generally attributed to glutamine accumulation, and cytotoxic oxidative/nitrosative damage. However, ammonia neurotoxicity is multifactorial, with disturbances also in neurotransmitters, energy production, anaplerosis, cerebral blood flow, potassium, and sodium. Around 90% of hyperammonemic patients have liver disease. Inherited defects are rare. They are being recognized increasingly in adults. Deficiencies of urea cycle enzymes, citrin, and pyruvate carboxylase demonstrate the roles of isolated pathways in ammonia metabolism. Phenylbutyrate is used routinely to treat inherited urea cycle disorders, and its use for hepatic encephalopathy is under investigation.

Unusual cause of hyperammonemia in two cases with short-term and long-term valproate therapy successfully treated by single dose carglumic acid

Valproic acid (VPA) is an antiepileptic drug which is used in the treatment of various seizure disorders including tonic-clonic, myoclonic, absence, partial seizures and psychiatric disorders. VPA is usually well tolerated, but severe adverse effects may occur. Hyperammonaemic encephalopathy (HE) is a rare and potentially fatal complication of VPA treatment. The mechanism by which valproate induces hyperammonemia remains incompletely understood but is likely to relate to the urea cycle. Herein we present two cases with valproate-induced hyperammonemia at therapeutic valproate levels without signs of liver failure and were successfully treated by a single dose of carglumic acid.

Risk factors for hyperammonemia in pediatric patients with epilepsy

PURPOSE

To identify risk factors for hyperammonemia in pediatric patients with epilepsy.

METHODS

A total of 2,944 pediatric patients (ages 0-15 years) were classified into the following three groups: a group without drug treatment (n = 445, group I), a group receiving antiepileptic drugs other than valproic acid (VPA) (n = 673, group II), and a VPA-treated group (n = 1,826, group III). Hyperammonemia was defined as a plasma ammonia level exceeding 100 μg/dl with reference to the standard range and previous reports.

KEY FINDINGS

The mean ammonia level of groups I, II, and III was 36.0, 56.0, and 86.8 μg/dl, respectively, and the incidence of hyperammonemia was 1.6%, 7.7%, and 31.7%, respectively. In each group, the mean ammonia level of patients aged 3 years or younger was significantly higher than that of patients aged 4-15 years. In group II, concomitant use of topiramate and zonisamide were risk factors for hyperammonemia (adjusted odds ratio [OR] 3.9, 95% confidence interval [CI] 1.7-9.2, and OR 3.5, 95% CI 1.9-6.5, respectively). In group III, the ammonia level increased in a VPA dose-dependent manner. At a VPA dose of 30 mg/kg, there was 4.3-fold increase in the incidence of hyperammonemia. The other significant risk factors identified were female gender (OR 1.3, 95% CI 1.0-1.6), symptomatic generalized epilepsy (OR 1.4, 95% CI 1.1-1.8), and the concomitant use of phenytoin (OR 4.7, 95% CI 3.3-6.9), phenobarbital (OR 2.2. 95% CI 1.6-3.2), acetazolamide (OR 6.6, 95% CI 2.5-17.2), topiramate, or zonisamide.

SIGNIFICANCE

A young age and concomitant use of carbonic anhydrase inhibitors are associated with an increased risk of hyperammonemia regardless of whether the patient is taking VPA. In patients receiving VPA, concomitant use of phenytoin and/or phenobarbital enhances the risk of hyperammonemia. An increase in ammonia can be caused by multiple factors. Our results may help clinicians to avoid problems of hyperammonemia.

Hyperammonemia in children: on the crossroad of different disorders

BACKGROUND

Symptoms of hyperammonemia occur in patients irrespective of the kind of metabolic diseases. Age, metabolic and nutritional status, and decompensation factors such as infections influence clinical manifestations. Prolonged, untreated hyperammonemia leads to brain injury and intellectual disability. Treatment is directed at lowering plasma ammonia. Brain ammonium concentrations are 1.5 to 3.0 times higher than that in blood.

REVIEW SUMMARY

The authors discuss the pathophysiology of the symptoms and consequences of hyperammonemia in children, focusing on the metabolic disorders leading to an increased level of ammonia.

CONCLUSIONS

Ammonia toxicity has been investigated for a long time. According to the main hypotheses, the neurological alterations are connected to alterations in glutamatergic neurotransmission.

Severe hyperammonaemia in adults not explained by liver disease

Ammonia is produced continuously in the body. It crosses the blood-brain barrier readily and at increased concentration it is toxic to the brain. A highly integrated system protects against this: ammonia produced during metabolism is detoxified temporarily by incorporation into the non-toxic amino acid glutamine. This is transported safely in the circulation to the small intestine, where ammonia is released, carried directly to the liver in the portal blood, converted to non-toxic urea and finally excreted in urine. As a result, plasma concentrations of ammonia in the systemic circulation are normally very low (<40 μmol/L). Hyperammonaemia develops if the urea cycle cannot control the ammonia load. This occurs when the load is excessive, portal blood from the intestines bypasses the liver and/or the urea cycle functions poorly. By far, the commonest cause is liver damage. This review focuses on other causes in adults. Because they are much less common, the diagnosis may be missed or delayed, with disastrous consequences. There is effective treatment for most of them, but it must be instituted promptly to avoid fatality or long-term neurological damage. Of particular concern are unsuspected inherited defects of the urea cycle and fatty acid oxidation presenting with catastrophic illness in previously normal individuals. Early identification of the problem is the challenge.

Hyperammonemia in review: pathophysiology, diagnosis, and treatment

Ammonia is an important source of nitrogen and is required for amino acid synthesis. It is also necessary for normal acid-base balance. When present in high concentrations, ammonia is toxic. Endogenous ammonia intoxication can occur when there is impaired capacity of the body to excrete nitrogenous waste, as seen with congenital enzymatic deficiencies. A variety of environmental causes and medications may also lead to ammonia toxicity. Hyperammonemia refers to a clinical condition associated with elevated ammonia levels manifested by a variety of symptoms and signs, including significant central nervous system (CNS) abnormalities. Appropriate and timely management requires a solid understanding of the fundamental pathophysiology, differential diagnosis, and treatment approaches available. The following review discusses the etiology, pathogenesis, differential diagnosis, and treatment of hyperammonemia.

Which psychotropic medications induce hepatotoxicity?

OBJECTIVE

Safe prescribing practices to minimize pharmaceutically induced liver damage or worsening of preexisting conditions require knowledge about medicines with hepatotoxic potential. This paper reviews psychotropic medications and their effects on the liver.

METHODS

A MEDLINE search was performed utilizing the phrase "drug-induced liver injury" with various categories of psychiatric drugs. Only articles written in English were utilized.

RESULTS

Hepatotoxicity can be acute or chronic in nature. Medication discontinuation is necessary in acute forms, while close monitoring is required in milder forms of medication-induced chronic liver damage. Nefazodone, pemoline and/or tacrine are the highest offenders. Carbamazepine and valproate products (e.g., divalproex) can lead to this adverse event and should be avoided in patients with liver disease, persons with alcohol misuse or those consuming high doses of acetaminophen.

CONCLUSION

Knowing the risk levels associated with various medicines is important; prescribing multiple drugs with hepatotoxic effects should be avoided. One should educate patients about early warning signs of liver injury. Always provide clinical and laboratory monitoring before and during the use of hepatotoxic drugs. Clinical features and laboratory results govern medication prescribing with ongoing risk-to-benefit ratio assessment during pharmacotherapy.

Transient hyperammonaemia in a patient with confusion: challenges with the differential diagnosis

Hyperammonaemia is often seen in the context of decompensated liver disease. It may also be triggered by stressful medical conditions in adults with partial enzyme deficiencies of the urea cycle. Occasionally, non-hepatic causes can result in hyperammonaemia severe enough to cause symptoms. The authors report the case of a 52-year-old Turkish woman who presented with acute-on-chronic confusion, drowsiness and lethargy. Laboratory investigations revealed hyperammonaemia which had an unclear cause. Although first thought to be secondary to a concurrent urinary tract infection, the high serum ammonia was eventually attributed to her carbamazepine. The authors recommend that doctors should include urinary tract infection and iatrogenic causes in their differential diagnosis in patients with hyperammonaemia and neurological symptoms, especially when this may be misleading in the diagnostic process.