Antipsychotic drugs antipsychotics side effects

After the introduction of the first neuroleptic drugs, many animal models were developed to screen new compounds for potential antipsychotic activity. These models predict both antipsychotic efficacy and side effect liability in humans (104-106). Other animal models at-... 

I Sedation and Cognition. Sedation must be recognized as an antipsychotic side effect and not as an indication of therapeutic effect. It occurs more frequently with antipsychotics with antihistaminic properties. Chlorpromazine, thioridazine, mesoridazine, clozapine, olanzapine, and quetiapine are most frequently implicated. Administration of most or all of the daily dosage at bedtime (depending on the drug half-life) can decrease daytime sedation and in some patients eliminate the need for hypnotic agents. Sedation occurs early in treatment... 

Figure 1.12 Schematic model of a central cholinergic nerve ending indicating possible sites of drug action. Attempts have been made to increase acetycholine synthesis (CAT= choline acetyltransferase) by increasing availability of choline but this has not been successful (1). ACh is stored in vesicles but there are no clinically effective drugs that act at this site (2). There is some evidence that aminopyridines and phosphatidylserines release ACh and may have limited use in Alzheimer s disease patients (3). Muscarinic antagonists are usedfor Parkinson s disease and antipsychotic-induced extrapyramidal side-effects. Presynaptic muscarinic autoreceptors...

The dihydroindolone molindone, though structurally different from the phenothiazine and butyrophenones, shares most of their antipsychotic properties and side effects. Its clinical effects resemble those of the piperazine phenothiazines. The drug s specific advantages, if any, are not readily apparent. 

B.l Common antipsychotics - approximate relative side effect profiles Appendix C Alcohol and drugs Appendix D Cognitive testing Appendix E Mental health legislation Appendix F Useful contacts Index... 

Chlorpromazine had been shown to produce a tranquil state in animals and since it had a similar effect in humans it became known as a major tranquiliser but the term is rarely used today. Sometimes the drugs used to treat schizophrenia are called anti-psychotics but more commonly neuroleptics. Leptic means to activate (take hold of) and in animals these compounds produce a state of maintained motor tone known as catalepsy. This is an extrapyramidal effect and in schizophrenics the neuroleptics can cause a number of extrapyramidal side-effects (EPSs) including Parkinsonism. The new term neuroleptic is unsatisfactory as a description of clinically useful drugs. It really describes a condition (catalepsy) seen in animals and is more indicative of a compound s ability to produce EPSs than to treat schizophrenia. Antipsychotic is more descriptive but could imply a more general efficacy in psychoses than is the case. It would seem more appropriate to call a drug that is used to treat schizophrenia an antischizophrenic just as we use the terms antidepressant or antiepileptic irrespective of how the drug works. Despite such personal reservations, the term neuroleptic will be used in this text. 

Tardive dyskinesia A chronic disorder of the nervous system characterized by involuntary jerky or writhing movements of the face, tongue, jaws, trunk, and limbs, usually developing as a late side effect of prolonged treatment with antipsychotic drugs. 

Akathisia The motor restlessness often noted as a side effect of long-term administration of typical antipsychotic drugs. 

Extrapyramidal side effects These are caused by antipsychotic drugs. They are characterised by motor and postural disturbances, of which the most serious is late-onset tardive dyskinesia. 

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