Tardive dyskinesia is characterized by repetitive, involuntary, potentially irreversible movements of the tongue, jaw, lips, trunk, or limbs.
- choreiform – rapid, jerky, non repetitive
- athetoid – slow, sinuous, continual
- rhythmic - stereotypic
It is a serious side effect of long-term use of drugs that block dopamine receptors, particularly D2- receptors.
Incidence: 2-4% per year of exposure.
Prevalence: 20% in patients receiving a typical antipsychotic for more than 3 months; it is most common in women, older persons, and those on high doses. It is less common in patients receiving atypical anti psychotics, such as resperidone.
Early diagnosis: wormlike movements of the tongue; inability to protrude tongue for more than a few seconds.
Treatment:
Responds poorly to treatment with drugs; withdrawal of the causal agent leads to resolution in 30% in 3 months and a further 40% in 5 years.
Some drugs to consider:
- Tetrabenazine: 12.5 mg to 25 mg q 8 h; increase the dose slowly to avoid troublesome hypotension.
- Levodopa may produce long-term benefit after causing initial deterioration.
Reus VI. Mental Disorders. Longo DL, Fauci AS, Kasper DL (Ed). Harrison’s Principles of Internal Medicine. 18th ed., Vol. 1, McGraw Hill, 2012. pp. 3529-3545.