Etrafon and Tardive dyskinesia

Phenothiazines may commonly precipitate symptoms of tardive dyskinesia (TD), a syndrome consisting of rhythmic involuntary movements variously involving the tongue, face, mouth, lips, jaw, and/or trunk and extremities, following chronic use of at least several months but often years. Elderly patients, particularly women, are most susceptible. Also, propylpiperazine derivatives like fluphenazine, perphenazine, prochlorperazine, and trifluoperazine may be more likely to induce this syndrome. Both the risk of developing TD and the likelihood that it will become irreversible increase with the duration and total cumulative dose of phenothiazine therapy administered. However, patients may infrequently develop symptoms after relatively brief treatment periods at low dosages. If TD occurs during phenothiazine therapy, prompt withdrawal of the offending agent or at least a lowering of the dosage should be considered. TD symptoms usually become more severe after drug discontinuation or a dosage reduction, but may gradually improve over months to years. In patients with preexisting drug-induced TD, initiating or increasing the dosage of phenothiazine therapy may temporarily mask the symptoms of TD but may eventually worsen the condition. The newer, atypical neuroleptic agents (e.g., risperidone, quetiapine, olanzapine) tend to be associated with a substantially reduced risk of inducing TD and are considered the drugs of choice in patients being treated for psychosis.

Tricyclic and tetracyclic antidepressants (TCAs) have anticholinergic activity, to which elderly patients are particularly sensitive. Tertiary amines such as amitriptyline and trimipramine tend to exhibit greater anticholinergic effects than other agents in the class. As with other drugs that possess anticholinergic activity, TCAs may aggravate tardive dyskinesia or induce previously suppressed symptoms. Patients with tardive dyskinesia requiring therapy with TCAs should be monitored for exacerbation of the condition.