<unk>  is a neurological disorder caused by the long-term or high-dose use of dopamine antagonists, usually antipsychotics. These neuroleptic drugs are generally prescribed for psychiatric disorders. Other dopamine antagonists that can cause<unk>  are drugs for gastrointestinal disorders (for example metoclopramide) and neurological disorders. Some drugs that are not intended to affect dopamine, such as SSRI antidepressants, may also cause<unk> . While newer atypical antipsychotics such as olanzapine and risperidone appear to have less dystonic effects, only clozapine has been shown to have a lower risk of<unk>  than older antipsychotics.
The term<unk>  was introduced in 1964.<unk>  refers to an impairment of voluntary movement. The resultant tics and other movements are often referred to as<unk> s.<unk>  is sometimes caused by long-term use of anti-psychotic drugs or other dopamine antagonists like the antiemetic metoclopramide. The effect of these drugs can be<unk> , meaning the<unk>  continues or appears even after the drugs are no longer taken. As far as treatment of iatrogenic<unk>  is concerned, neuroleptic drugs should be withdrawn for a period of 3-6 months to see if this resolves the issue, but the problem may fail to improve or may even exacerbate. In this situation, it would be sensible to trial the patient on tetrabenazine 25-50 mg/8h PO.(Oxford Handbook of Clinical Medicine).
In context of Parkinson's disease,<unk> s are often the result of chronic levodopa (L-dopa) therapy. These motor fluctuations occur in more than half of PD patients after 5 to 10 years of levodopa therapy, with the percentage of affected patients increasing over time.<unk> s most commonly occur at the time of peak L-dopa plasma concentrations and are thus referred to as peak-dose<unk> s. As patients advance, they may evidence diphasic<unk> s, which occur when the drug concentration rises or falls.
The use of MDMA has been shown to enhance the effects of L-Dopa while reducing the associated<unk>  in primates with simulated Parkinson's disease.
Tardive dyskinesia
Akinetic-rigid syndromes
Pseudoathetosis
Akathisia
Biliary dyskinesia
Episodic ataxia
Chorea
Choreoathetosis