TRICYCLIC ANTIDEPRESSANT-INDUCED EXTRAPYRAMIDAL SIDE-EFFECTS

Two cases of tricyclic antidepressant-related extrapyramidal side effe cts are reported and, the authors review the literature describing the se effects. Despite clear case reports, these side effects are not wel l known. Given the wide prescription of tricyclic antidepressants (TCA ) and the low number of case reports, the prevalence of these side eff ects is indeed low, but clinical implications exist. The extrapyramida l symptoms induced by TCA alone are acute or tardive dyskinesia, akath isia, myoclonus, rabbit syndrome and dystonia. These symptoms seem to be non age-related, but often dose-related, and were responders to ant iparkinsonian agents or propranolol. The factors that predispose an in dividual to the development of these side effects are not completely u nderstood. Some risk factors such as prior exposure to neuroleptics an d/or lithium or estrogens could facilitate the development of these si de effects. In some cases, they can disappear even though the same dos e of TCA is continued, and they do not seem to be a drug class reactio n. The susceptibility of each individual patient to the development of these disorders may be limited to only one or a few of these agents. (C) 1997 Elsevier Science B.V.