Incidence of Adverse Reactions to Parenteral Thiamine in the Treatment of Wernicke's Encephalopathy, and Recommendations

Management of alcohol withdrawal syndromes in general hospital settings

The covid-19 pandemic was associated with an unprecedented increase in alcohol consumption and associated morbidity, including hospitalizations for alcohol withdrawal. Clinicians based in hospitals must be ready to identify, assess, risk-stratify, and treat alcohol withdrawal with evidence based interventions. In this clinically focused review, we outline the epidemiology, pathophysiology, clinical manifestations, screening, assessment, and treatment of alcohol withdrawal in the general hospital population. We review and summarize studies addressing the drug treatment of alcohol withdrawal syndromes in inpatient populations, with a focus on the use of benzodiazepine drugs, phenobarbital, antiseizure drugs, and α-2 adrenergic drugs. Emerging areas of interest include the use of novel alcohol biomarkers, risk stratification instruments, alternative symptom severity scales, severe withdrawal syndromes resistant to benzodiazepine drugs, and treatment protocol variations-including non-symptom-triggered and benzodiazepine-sparing protocols. We identify key areas for research including identification of populations who will benefit from non-benzodiazepine strategies, more individualized risk stratification approaches to guide treatment, and greater inclusion of gender and racial and ethnic minorities in future studies.

Treatment variability and its relationships to outcomes among patients with Wernicke's encephalopathy: A multicenter retrospective study

BACKGROUND

Despite guidelines and recommendations, Wernicke's encephalopathy (WE) treatment lacks evidence, leading to clinical practice variability.

AIMS

Given the overall lack of information on thiamine use for WE treatment, we analyzed data from a large, well-characterized multicenter sample of patients with WE, examining thiamine dosages; factors associated with the use of different doses, frequencies, and routes; and the influence of differences in thiamine treatment on the outcome.

METHODS

This retrospective study was conducted with data from 443 patients from 21 centers obtained from a nationwide registry of the Spanish Society of Internal Medicine (from 2000 to 2012). Discharge codes and Caine criteria were applied for WE diagnosis, and treatment-related (thiamine dosage, frequency, and route of administration) demographic, clinical, and outcome variables were analyzed.

RESULTS

We found marked variability in WE treatment and a low rate of high-dose intravenous thiamine administration. Seventy-eight patients out of 373 (20.9%) received > 300mg/day of thiamine as initial dose. Patients fulfilling the Caine criteria or presenting with the classic WE triad more frequently received parenteral treatment. Delayed diagnosis (after 24h hospitalization), the fulfillment of more than two Caine criteria at diagnosis, mental status alterations, and folic acid deficiency were associated significantly with the lack of complete recovery. Malnutrition, reduced consciousness, folic acid deficiency, and the lack of timely thiamine treatment were risk factors for mortality.

CONCLUSIONS

Our results clearly show extreme variability in thiamine dosages and routes used in the management of WE. Measures should be implemented to ensure adherence to current guidelines and to correct potential nutritional deficits in patients with alcohol use disorders or other risk factors for WE.

Vertigo-Associated Vomiting: Acute Presentation of Thiamine Deficiency in Intestinal Failure

Thiamine deficiency can manifest as Wernicke encephalopathy, with the classic clinical triad of altered mental status, nystagmus, and ataxia. Although a rare diagnosis in pediatric patients within developed countries, gastrointestinal disorders that impair nutritional intake and absorption can place patients at higher risk. Rapid diagnosis and early empiric treatment of Wernicke encephalopathy is paramount due to high risk of mortality and long-term morbidity. We present a patient with intestinal failure who developed thiamine deficiency following weaning off parenteral nutrition with acute onset of vertigo-associated vomiting. In the absence of consensus guidelines for treatment dosing and duration, in both adult and pediatric populations, we review prior pediatric cases and propose a strategy for dosing with symptom-guided step-up approach to maximize treatment efficacy in a time-conscious manner.

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5. These B-complex vitamins must be taken from diet, with the exception of vitamin B3, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B3, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Wernicke-Korsakoff syndrome and other diseases associated with thyamine deficiency

Wernicke-Korsakoff syndrome is the best known consequence of thiamine deficiency, frequently associated with patients with chronic and excessive alcohol consumption, but it can be produced by any cause that produces thiamine deficiency. The disease is underdiagnosed so it is essential to have a high clinical suspicion, mainly in patients who do not have alcohol consumption as a risk factor. For this, the diagnosis continues to be eminently clinical, with the difficulty of high clinical variability. Complementary tests are used to support the diagnosis and rule out other causes that can produce similar symptoms, with magnetic resonance imaging being the most cost-effective imaging test. Treatment is based on the administration of thiamine, which should be started early, and parenterally at the appropriate doses, in all patients with compatible symptoms, without waiting to confirm the diagnosis.

Pharmacokinetics of thiamine (vitamin B1) in adult horses after administration of three single intravenous doses

Thiamine is a vital co-factor for several anti-inflammatory and antioxidant processes that are critical for mitigation of sepsis-associated inflammation, but pharmacokinetic (PK) analysis has not been reported in horses. We hypothesized that IV thiamine hydrochloride (TH) at increasing dosages would result in corresponding increases in plasma thiamine concentrations without causing adverse effects. A randomized cross-over study was performed in 9 healthy horses that each received TH at 5, 10, and 20 mg/kg IV. Blood was collected immediately prior to drug administration and at several time points thereafter. High-performance liquid chromatography with mass spectrometry was used to quantify thiamine concentrations at each time point. Non-compartmental PK methods showed that IV TH resulted in supraphysiologic plasma concentrations with a short half-life (0.77-1.12 h) and no adverse clinical signs were observed. The terminal rate constant decreased as the dosage increased (p < .0001) and clearance significantly decreased at the 20 mg/kg dosage (p = .0011). The area under the curve (AUC) increased in a non-linear fashion. These findings suggest that thiamine follows non-linear elimination kinetics in horses, which is likely due to saturation of renal elimination. Future studies are needed to identify therapeutic plasma concentrations and develop thiamine dosing recommendations for horses.

Wernicke's Encephalopathy in Alcohol Use Disorder Patients after Liver Transplantation: A Case Series and Review of Literature

Wernicke’s encephalopathy (WE) is an acute neurological disorder resulting from thiamine deficiency, commonly found in alcohol use disorder (AUD) patients. Liver transplantation (LT) could represent a risk factor for the onset of WE in AUD patients, due to the onset of chronic depletion of thiamine in this population and the high metabolic demand of surgery and the postoperative period. However, few data are available about the risk of the onset of WE in AUD patients after LT. Here we report three cases of AUD patients who developed WE with confusion and delirium after LT. Prompt parenteral administration of thiamine led to a rapid improvement of the clinical condition and a complete remission of neurological symptoms after 3–4 days. In addition, a search of the available English literature was conducted in order to perform a review of the possible association between the onset of WE and LT in AUD patients. A prophylactic treatment regimen based on the administration of thiamine could be suggested in AUD patients before and after LT. Further studies are needed to determine the optimal regimen of thiamine in the prevention of WE in this setting.

Improving thiamine prescribing at an academic hospital network using the computerized provider order entry system: a cohort study

BACKGROUND

Oral thiamine therapy is frequently prescribed to patients at risk for thiamine deficiency despite recommendations emphasizing the need for high doses of parenteral thiamine to reverse brain thiamine deficits. We evaluated the effect of changes to the computerized provider order entry system on the proportion of prescriptions for parenteral thiamine treatment (primary outcome) and dosages prescribed (secondary outcome) within our academic hospital network.

METHODS

We obtained data from the pharmacy information system recording thiamine prescribed to inpatients at University Health Network hospitals (Toronto, Ontario) before (Jan. 1, 2010, to Dec. 31, 2011) and after (Nov. 21, 2013, to Apr. 30, 2017) changes to the computerized provider order entry system promoting the use of higher dosages (≥ 200 mg) of parenterally administered thiamine. Patients receiving thiamine as part of total parenteral nutrition were excluded from analyses, as thiamine prescribing was automated and unlikely to be affected by the intervention.

RESULTS

A total of 6105 thiamine prescriptions were written for 2907 patients before the intervention and 12 787 thiamine prescriptions for 8032 patients after the intervention. The proportion of prescriptions for parenteral treatment increased from 55.5% (3386/6105) to 92.5% (11 829/12 787) after the intervention (p < 0.001). Increases in prescribing of parenteral thiamine treatment were sustained or enhanced across the 3.4-year observation period and were realized across all hospital services. Prescriptions for higher dosages of thiamine increased from 1.1% (65/6105) to 61.4% (7845/12 787) after the intervention (p < 0.001).

INTERPRETATION

Changes to the computerized provider order entry system were associated with sustained increases in the proportion of prescriptions for high-dose parenteral thiamine therapy. Similar approaches may be leveraged to align prescriber behaviour with well-accepted practice parameters in other areas of medicine.