Teriflunomide

How it works

It inhibits dihydro-orotate dehydrogenase, reducing de novo pyrimidine synthesis in rapidly dividing lymphocytes and thereby limiting the proliferation of activated T and B cells involved in the autoimmune attack on myelin.

Prescribing in practice

• It is teratogenic and contraindicated in pregnancy; effective contraception is essential and, because of prolonged retention, an accelerated elimination procedure is used before conception or if serious toxicity occurs.
• It can cause hepatotoxicity, so liver function should be checked before and during treatment.
• Hypertension, hair thinning and diarrhoea are recognised effects.

Monitoring

Monitor liver transaminases, full blood count and blood pressure before and periodically during treatment, and screen for latent tuberculosis beforehand.

Counselling the patient

• Use reliable contraception throughout treatment and tell your clinician at once if you might be pregnant.
• Report yellowing of the skin or eyes, dark urine or persistent nausea, as these may signal a liver problem.

Evidence & guidelines

Efficacy in relapsing MS was established in the TEMSO and TOWER randomised controlled trials, and its use is consistent with NICE guidance.