Antipsychotics



- Phenothiazines
    - Chlorpromazine
    - Thioridazine
    - Mesoridazine
    - Fluphenazine
- Thiothixenes
    - Thiothixene
- Butyrophenones
    - Haloperidol
- Discussion:
    - in low doses they are useful for the management of the agitation and confusion of delirium and dementia;
    - elderly may be more susceptible to effects of given dose of Chlorpromazine, since oral therapy w/ that drug results in higher plasma levels in elderly;
    - relatively more potent agents, esp Haloperidol & Fluphenazine, cause highest incidence of side effects in extrapyramidal system, including pseudo-Parkinsonism, akathisias, and dystonias;
    - because of age-related changes in the central nervous system, elderly are more prone to have extrapyramidal symptoms of pseudo-Parkinsonian type, but they are less likely to have dystonias than younger patients;
    - immediate management of such effects should involve tapering dosage or discontinuing drug if possible & using anticholinergic medication;
         - long-term use of anticholinergic medications in this manner is not recommended, since it may increase risk for tardive dyskinesia & cause other anticholinergic side effects, including delirium;
    - pts w/ early development of other types of extrapyramidal symptoms, such as akathisias or pseudo-Parkinsonism, may also be more likely to acquire tardive dyskinesia;
         - it may be wise to use a neuroleptic w/ lower potency, such as Chlorpromazine or Thioridazine, in pts w/extrapyramidal side effects;
         - Thioridazine has lowest incidence of extrapyramidal symptoms & may cause least dopaminergic blockade in the striatum;
    - least potent antipsychotics (Chlorpromazine & Thioridazine tend to be most sedating and to have most anticholinergic effects;
    - least potent antipsychotics (Chlorpromazine & Thioridazine) tend to be most sedating and to have most anticholinergic effects;
         - use of such drugs in combination w/ antidepressant that also has high anticholinergic activity may cause toxic anticholinergic reactions, including delirium;
         - autonomic side effects are also relatively frequent w/ less potent neuroleptics, & resultant hypotensive episodes may predispose to falls, myocardial infarction, or CVA



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, August 9, 2012 10:19 am