Tocilizumab

How it works

It binds to interleukin-6 receptors, blocking IL-6 mediated pro-inflammatory signalling that drives joint inflammation and the acute-phase response.

Prescribing in practice

• It increases the risk of serious infections, including tuberculosis and other opportunistic infections, so screening before starting and vigilance for infection are essential, and it should not be started during active infection.
• It can cause neutropenia, thrombocytopenia, raised liver enzymes and dyslipidaemia, and rare cases of gastrointestinal perforation have occurred, particularly in those with diverticulitis.
• It can mask the signs of infection by suppressing the acute-phase response, so clinical assessment should not rely on CRP or fever alone; live vaccines should be avoided.

Monitoring

Monitor neutrophil and platelet counts, liver enzymes and lipids at baseline and periodically, and remain alert for infection.

Counselling the patient

• Report signs of infection such as fever, persistent cough or feeling generally unwell promptly.
• Seek urgent advice for severe abdominal pain, which could indicate a serious bowel problem.
• Avoid live vaccines and tell other clinicians you are on this treatment.

Evidence & guidelines

NICE recommends tocilizumab for rheumatoid arthritis and giant cell arteritis within defined criteria, supported by randomised controlled trial evidence.