Tetrabenazine

How it works

It reversibly inhibits vesicular monoamine transporter 2 (VMAT2), depleting presynaptic stores of dopamine and other monoamines and so reducing involuntary movements.

Prescribing in practice

• It can cause or worsen depression and suicidal ideation, so patients should be assessed for low mood and monitored, and it is contraindicated in those with untreated or inadequately treated depression.
• Parkinsonism, sedation, akathisia and, rarely, a neuroleptic malignant syndrome-like reaction can occur.
• It should be avoided alongside monoamine oxidase inhibitors and used cautiously with other dopamine-blocking or QT-prolonging drugs.

Monitoring

Monitor mood and for emerging suicidal thoughts, alongside parkinsonian features, swallowing and signs of QT prolongation.

Counselling the patient

• Report any worsening mood, hopelessness or thoughts of self-harm promptly.
• Tell your clinician if you become stiff, slow, very drowsy or develop restlessness.

Evidence & guidelines

Benefit on chorea in Huntington's disease is supported by randomised controlled trial data and reflected in its licensed indication.