Products and availability

Issues affecting Pabrinex

Pabrinex, which contains thiamine, has been used for the prophylaxis and treatment of Wernicke’s encephalopathy. However, intramuscular Pabrinex has been discontinued, and intravenous Pabrinex is affected by a long term supply issue. Supplies will not be available after August 2024.

There are no other licensed parenteral alternatives to Pabrinex intravenous and intramuscular injections.

Thiamine

Intravenous or intramuscular thiamine is an alternative to Pabrinex that can be used in people at high risk of Wernicke’s encephalopathy, although no product with a marketing authorisation currently exists in the UK.

Organisational actions

Organisations should undertake a number of actions to ensure Pabrinex stock is preserved and thiamine is used appropriately.

Review local protocols

Identify and review any local protocols for alcohol dependence and amend these as necessary.

Source parenteral thiamine

The medicines supply tool entry contains details on sourcing parenteral thiamine.

Prophylaxis for people at risk

Defining people at risk

NICE CG100 recommends to offer prophylactic parenteral thiamine followed by oral thiamine to harmful or dependent drinkers if they:

• are malnourished or at risk of malnourishment or
• have decompensated liver disease

and in addition:

• they attend an emergency department or
• are admitted to hospital with an acute injury or illness

People at high risk of Wernicke’s encephalopathy can have a range of conditions, including:

• significant weight loss
• poor diet
• low BMI (<18)
• other signs of malnutrition
• memory disturbance
• peripheral neuropathy
• previous history of Wernicke’s encephalopathy

Consider offering prophylactic parenteral thiamine to people at high risk following the dosing below.

Community setting doses

• give intramuscular thiamine 200 to 300mg once daily for at least 3 days

Hospital setting doses

• give intramuscular thiamine or intravenous thiamine 200 to 300mg once daily for 3 to 5 days with daily review and monitoring for emergent signs of Wernicke’s encephalopathy

Treating Wernicke’s encephalopathy

Identifying symptoms

People with any of the additional symptoms below require treatment for Wernicke’s encephalopathy.

• impaired eye movements (ophthalmoplegia)
• unsteady walking (ataxia)
• confusion

Hospital setting doses

• give intravenous thiamine 300 to 500mg three times a day for 3 to 5 days with daily review
• if the individual is still symptomatic after 5 days of treatment, then give intravenous thiamine 300mg to 500mg once daily for a further 3 to 5 days for as long as clinical improvement continues
• other causes for their confusion should be explored

Evidence behind the recommendations

Office for Health Improvement and Disparities (OHID) and DHSC convened a group of 11 expert clinicians (drawn mainly from the clinical reference group for the UK clinical guidelines on alcohol treatment) chaired by Dr Mike Kelleher (Consultant Addiction Psychiatrist) National Clinical Advisor for alcohol and drugs to OHID (DHSC).

Based on a review of the available evidence that showed a lack of evidence supporting the dose of Pabrinex and lack of robust evidence on dosing of thiamine in Wernickes, the expert committee decided not to recommend a direct dose conversion from Pabrinex. Instead, a consensus on recommendations for intramuscular and intravenous thiamine was reached which considered national and international guidelines, clinical experience, and consultations with international specialists.

Clinicians should use their clinical judgement on dosing of thiamine within the dose range recommended by the group.

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