Anticholinergic drugs tardive dyskinesia

Acute dystonias occur immediately after neuroleptization and are manifested by motor impairments, particularly in the head, neck, and shoulder region. After several days to months, a parkinsonian syndrome (pseudoparkinsonism) or akathisia (motor restlessness) may develop. All these disturbances can be treated by administration of antiparkin-son drugs of the anticholinergic type, such as biperiden (i.e., in acute dystonia). As a rule, these disturbances disappear after withdrawal of neuroleptic medication. Tardive dyskinesia may become evident after chronic neuroleptization for several years, particularly when the drug is discontinued. It is due to hypersensitivity of the dopamine receptor system and can be exacerbated by administration of anticholinergics. 

Neuroleptic drugs can produce a variety of adverse effects in several organ systems. Extrapyramidal reactions and sedation are common less common are seizures, unwanted behavioral effects, and tardive dyskinesia. Most neuroleptic drugs have anticholinergic effects and commonly produce dry mouth, blurred vision, and constipation. Postural hypotension is common. These effects usually disappear when the drug is stopped or the dosage is reduced. 

In a retrospective study in a psychiatric hospital in Curasao, Netherlands Antilles, 133 Afro-Caribbean inpatients (mean age 52 years), with no organic disorders and a history of current use of neuroleptic drugs for at least 3 months, were assessed for tardive dyskinesia (291). The prevalence was 36%. When the number of interruptions to neuroleptic drug therapy was split into up to two and more than two, the resulting adjusted odds ratio was 3.29 (95% Cl = 1.27, 8.49). Thus, the number of interruptions turned out to be the second risk factor after age. Cumulative dosages of neuroleptic or anticholinergic drugs were not risk factors. 

Gardos G, Cole JO. Tardive dyskinesia and anticholinergic drugs. Am J Psychiatry 1983 140(2) 200-2. 

From the perspective of tolerability, these new atypicals are clearly superior to conventionals. The rates of extrapyramidal symptoms, tardive dyskinesia, and anticholinergic effects are much lower. Flowever, as their use has become more commonplace, these drugs appear to have their own adverse effects, some of which have raised substantial concerns. They include increased rates of extrapyramidal symptoms at higher than usual doses, prolactin elevations, and electrocardiogram changes. 

There Is abundant evidence chat medication with anticholinergic drugs Is contraindicated In human tardive dyskinesia (302-309). Burnett et al. (308) found chat the Improvement In tardive dyskinesia after discontinuance of the anticholinergic drug, when both an anticholinergic compound and a neuroleptic drug had been used to treat schizophrenia, was not due to any change In the patients serum concentration of... 

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