Tocilizumab (ICU — Cytokine Storm / COVID-19)

How it works

It binds soluble and membrane-bound IL-6 receptors, blocking IL-6 signalling and dampening the systemic inflammatory cascade that drives organ dysfunction in cytokine storm.

Prescribing in practice

• By suppressing immune responses it increases the risk of serious infection (including reactivation of tuberculosis and hepatitis B), so exclude active uncontrolled infection before giving it.
• In COVID-19 it is used together with a corticosteroid in patients with rapid respiratory deterioration and raised inflammatory markers, not as monotherapy.
• It can cause neutropenia, thrombocytopenia, transaminase elevation, and rarely gastrointestinal perforation, so review blood counts and liver function.

Monitoring

Monitor full blood count, liver function, and for emerging infection following administration, since IL-6 blockade can mask the usual signs of sepsis.

Counselling the patient

• Warn the patient and team that signs of infection may be blunted and any new fever or deterioration needs prompt review.
• Note that tocilizumab is given alongside steroid therapy in severe COVID-19.
• Advise that blood tests will check white cells, platelets, and liver enzymes.

Evidence & guidelines

The RECOVERY trial demonstrated a survival benefit from tocilizumab in hospitalised patients with severe COVID-19 and systemic inflammation, supporting its NHS use with corticosteroids.