Thiamine Prescribing Practices for Adult Patients Admitted to an Internal Medicine Service

What is the optimum thiamine dose to treat or prevent Wernicke's encephalopathy or Wernicke-Korsakoff syndrome? Results of a randomized controlled trial

Background

The primary cause of Wernicke–Korsakoff syndrome (WKS) is thiamine deficiency, and more than 90% of cases are reported in alcohol‐dependent patients. While observational studies show parenteral thiamine administration drastically reduced WKS‐related mortality, relevant treatment trials have never been conducted to determine the optimum thiamine dose.

Methods

Two double‐blind, parallel groups, randomized controlled trials (RCTs) were conducted to determine the optimal thiamine dose required for (1) the prevention of Wernicke's encephalopathy (WE), the acute phase of WKS, in asymptomatic but “at‐risk” alcohol misuse patients (Study 1) and (2) the treatment of WE in symptomatic alcohol misuse patients (Study 2). Each study had a dosage regimen comprising three parenteral thiamine doses that were allocated at a ratio of 1:1:1. Study 1: Asymptomatic At‐Risk patients (N = 393) received either 100 mg daily, 100 mg thrice daily, or 300 mg thrice daily, for 3 days. Study 2: Symptomatic patients (N = 127) received either 100 mg thrice daily, 300 mg thrice daily, or 500 mg thrice daily, for 5 days. Cognitive function was the primary outcome, assessed using the Rowland Universal Dementia Assessment Scale, two Cogstate subtests, and an adapted Story Memory Recall test. Secondary analyses examined differences in neurological function (ataxia, oculomotor abnormalities, and confusion) at follow‐up.

Results

No significant differences were observed between any of the dosage conditions for either Study 1 or Study 2 on cognition or neurological functioning. This real‐world study found that having a clinically unwell target population with high comorbidity and multiple presentations, coupled with challenges in cross‐cultural assessment is likely to complicate RCT findings.

Conclusions

The results of this study showed no clear benefit of high dose thiamine over intermediate or lower doses of thiamine, over the time intervals examined, for the treatment and prevention of cognitive and neurological abnormalities related to WKS. Several study limitations temper the interpretation of these findings. Nevertheless, the absence of conclusive evidence for the superiority of high‐dose thiamine supports a recommendation for patient‐specific treatment, while ensuring that the potential impact of other biochemical factors (e.g., magnesium and other B vitamin deficiencies) are considered and corrected if necessary.

Thiamine supplementation in hospitalized patients with altered mental status: does it help?

OBJECTIVE

To describe thiamine-prescribing patterns and to study the association of thiamine supplementation with clinical outcomes in hospitalized patients with altered mental status (AMS).

METHODS

We conducted a retrospective cohort study of all adult hospitalized patients with AMS with index admission in calendar year 2017. We studied the association of a) supplemental thiamine and b) timing of thiamine relative to glucose, with hospital outcomes - length of stay (LOS), 90-day readmission rates, and mortality rates - using linear, logistic, and extended Cox models, respectively. We also modeled association of supplemental thiamine on time to resolution of AMS using extended Cox models in patients admitted with AMS.

RESULTS

Of 985 patients, 178 (18%) received thiamine, including 123 (12.5%) who received thiamine before, with, or without glucose (thiamine first). We identified 365 (37%) patients who received intravenous glucose before or without thiamine (glucose first). We found that patients who received glucose first had longer LOS and higher rate of in-hospital deaths compared to those who did not. Patients who received thiamine supplementation had longer LOS compared to those who did not. There were no significant differences in other hospital outcomes or AMS resolution by discharge compared to their respective reference groups.

CONCLUSION

Although thiamine supplementation was not associated with better hospital or cognitive outcomes, we do not have enough evidence to suggest a change in current practice. Thiamine must be administered prior to glucose in hospitalized patients with AMS.

Low rates of thiamine prescribing in adult patients with alcohol-related diagnoses in the emergency department

Background: Alcohol use disorder (AUD) is associated with thiamine deficiency and Wernicke-Korsakoff Syndrome (WKS). Thiamine supplementation for the prevention of WKS in patients with suspected AUD in the Emergency Department (ED) is generally recommended. As alcohol-related diagnoses are frequent reasons for visits to EDs, ED thiamine prescribing practices are relevant to the overall management and prevention of WKS in patients with AUD.Objective: To determine the prescription rates of thiamine to patients with alcohol-related diagnoses in the ED.Methods: This was a retrospective chart review conducted at two New York City urban teaching hospitals from January 1 to December 31, 2017. All patients 18 years or older who were given an alcohol-related diagnosis (all F10 ICD-10-CM codes) upon disposition were included. Collected data included details of thiamine prescribing practices, patient demographics and patient disposition.Results: A total of 7,529 patient visits with an alcohol-related diagnosis were identified. The overall median age of included patients was 44; 5747 (76.3%) patient visits were by men; 310 (4.1%) patient visits resulted in admission. Out of all patient visits, thiamine was ordered during 167 (2.2%) visits, with thiamine administered parenterally during 129 (77.2%) visits and orally in 38 (22.8%) visits. Out of patient visits specifically associated with an F10.2 (Alcohol Dependence) diagnosis, thiamine was ordered during 105 (17.8%) visits.Conclusion: We found a very low rate of thiamine prescribing during patient visits associated with alcohol-related diagnoses. This may be a missed opportunity to reduce morbidity and mortality among AUD ED patients.

The Changes in Antioxidant Activity of Selected Flavonoids and Caffeine Depending on the Dosage and Form of Thiamine

Phenolic compounds and thiamine may serve as therapies against oxidative stress-related neurodegenerative diseases. However, it is important to note that these components show high instability under changing conditions. The study’s aim was to determine the impact of the thiamine concentration (hydrochloride—TH and pyrophosphate—TP; in the range 0.02 to 20 mg/100 g on the indices of the chelating properties and reducing power, and free radicals scavenging indices of EGCG, EGC, ECG and caffeine added from 0.04 to 6.0 mg/100 g. Our research confirmed that higher concentrations of TH and TP can exhibit significant activity against the test antioxidant indices of all components. When above 5.0 mg/100 g of thiamine was used, the radical scavenging abilities of the compound decreased in the following order: EGCG > ECG > EGC > caffeine. The highest correlation was found for the concentration of thiamine pyrophosphate to 20.0 mg/100 g and EGCG. Knowledge of the impact of factors associated with the concentration of both EGCG, EGC, ECG or caffeine and thiamine on their activity could carry weight in regulating the quality supplemented foods, especially of nutrition support for people of all ages were oral, enteral tube feeding and parenteral nutrition).

Thiamine Dosing for the Treatment of Alcohol-Induced Wernicke's Encephalopathy: A Review of the Literature

Objective: To determine the most appropriate thiamine replacement regimen by evaluating safety and efficacy of the drug specific to alcohol-induced Wernicke's encephalopathy (WE). Data Sources: A comprehensive literature search was conducted using PubMed, MEDLINE, Scopus, and ProQuest between January and August 2020 using the following keyword and Boolean search terminology: "thiamine" AND "alcohol" AND (encephalopathy OR korsakoff). Study Selection and Data Extraction: Randomized control trials; prospective, observational, and retrospective cohort analyses; and case reports and series were included in this evaluation. A confirmed diagnosis of alcohol-induced WE and treatment with parenteral or intramuscular (IM) thiamine were required for inclusion. Data Synthesis: Six publications composed of 138 patients were evaluated in this review, in which a wide variety of thiamine supplementation strategies were employed. Clinical diagnostic criteria varied significantly between publications. Doses ranged from 100 to 1500 mg intravenous thiamine and up to 300 mg IM thiamine, with no apparent difference in patient outcomes. All patients who received thiamine experienced symptom improvement, and adverse drug events were minimal. Conclusions: Despite the clinical controversy regarding the appropriate thiamine supplementation regimen, the heterogeneity of published works combined with symptom resolution across the gamut of dosing strategies makes a definitive consensus elusive. Clinicians should continue to provide parenteral or IM thiamine in doses of ≥100 mg to patients with confirmed alcohol-induced WE.

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.