Stability of high-dose thiamine in parenteral nutrition for treatment of patients with Wernicke's encephalopathy

Summary Background & aims Wernicke's encephalopathy is associated mainly with malnourishment in alcohol-dependent patients but can be caused also by cancer, Crohn's disease, gastrointestinal surgery or prolonged parenteral nutrition (PN) without adequate supplementation of vitamins. The disorder, with a significant mortality rate of up to 20%, is often associated with the underlying disease and intensifies after administration of non-supplemented PN. Thus, it seems justified to add thiamine to PN admixtures prepared for parenterally fed patients. Due to the lack of data on the stability of thiamine in PN admixtures at concentrations exceeding 60 mg/L, we decided to determine the possibility of adding a high dose of thiamine (800 mg per bag, 320 mg/L) to PN admixtures in order to treat Wernicke's encephalopathy in malnourished patients. Methods The study aimed to assess the stability of the physical properties of PN admixtures (pH, zeta potential, particle size) and to determine thiamine content using an HPLC method. Results Thiamine was found to degrade regardless of the PN admixture composition and storage conditions. The highest decrease in thiamine content was observed at room temperature without light protection whereas the lowest at a temperature of 4 ± 1 °C with light protection. Conclusions The treatment of Wernicke's encephalopathy in parenterally fed patients is possible with the use of high thiamine doses (800 mg) added to PN admixtures without a decrease in the drug content above 10% within the first 24 h. It should be emphasized that thiamine as a photosensitive drug must be stored and administered under conditions ensuring light protection.