Extrapyramidal effects, of antipsychotics

Aggravation of the extrapyramidal effects of antipsychotic agents have been described and it has been reported that the use of lithium in combination with haloperidol may result in irreversible neurological toxicity. Lithium can increase the hypothyroid effects of antithyroid agents or iodides. 

EXTRAPYRAMIDAL EFFECTS OF ANTIPSYCHOTICS The acute adverse clinical effects of antipsychotic agents are best mimicked in animals by assessing catalepsy in rats (immobility that allows an animal to be placed in abnormal postures that persist) or dystonia in monkeys. Late dyskinetic effects of antipsychotics are represented by the development of vacuous chewing... 

The side effects of conventional antipsychotics are of even greater concern when treating chronic psychosis in a patient with dementia. With sustained administration of a typical antipsychotic, these patients will be highly vulnerable to the extrapyramidal effects of the medication, which can increase the risk for falls. Thus, atypical antipsychotics have also been rapidly accepted as first-line agents when treating... 

Extrapyramidal symptoms may occur as a side-effect of antipsychotic drugs. 

Tertiary-amine muscarinic receptor antagonists gain access to the central nervous system and are therefore the anticholinergic drugs used to treat parkinsonism and the extrapyramidal side effects of antipsychotic drugs. Specific agents used primarily for these conditions include benztropine mesylate (Cogentin) and trihexyphenidyl hydrochloride (Artane, others). 

Ossowska K, Pietraszek M, Wardas J, Wolfarth S. 2004. Potential antipsychotic and extrapyramidal effects of (R,S)-3,4-dicarboxyphenylglycine [(R,S)-3,4-DCPG], a mixed AMPA antagonist/mGluR8 agonist. Pol j pharmacol 56 ... 

Tandon R, Jibson MD. Extrapyramidal side effects of antipsychotic drug treatment scope of problem and impact and outcome. Ann Clin Psychiatry 2002 14 123-129. 

C) Prevents extrapyramidal adverse effects of antipsychotic drugs... 

Miller DD, Caroff SN, Davis SM, Rosenheck RA, McEvoy JP, Saltz BL, Riggio S, Chakos MH, Swartz MS, Keefe RS, Stroup TS, Lieberman JA. Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) Investigators. Extrapyramidal side-effects of antipsychotics in a randomised trial. Br J Psychiatry 2008 193(4) 279 8. 

Among the most significant adverse reactions associated with the antipsychotic dm are the extrapyramidal effects. The term extrapyramidal effects refers to a group of adverse reactions occurring on the extrapyramidal portion of the nervous system as a result of antipsychotic drains. This part of the nervous system affects body posture and promotes smooth and uninterrupted movement of various muscle groups. Antipsychotics disturb the function of the extrapyramidal portion of the nervous system, causing abnormal muscle movement. Extrapyramidal effects include Parkinson-like symptoms (see Chap. 29), akathisia, and dystonia (see Display 32-1). 

Extrapyramidal effects usually diminish with a reduction in the dosage of the antipsychotic drug. The primary health care provider may also prescribe an antiparkinsonism drug, such as benztropine (see Chap. 29) to reduce the incidence of Parkinson-like symptoms. 

When administering the antipsychotic drugs, the nurse observes the patient for extrapyramidal effects , which include muscular spasms of the face and neck, the inability to steep or s t still, tremors rigidity, or involuntary rhythmic movements The nurse notifiesthe primary health care provider of the occurrence of these symptoms because they may indicate a need for dosage adjustment. 

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. 

Extrapyramidal symptoms (EPS) Adverse effects of medications such as antipsychotics. EPS include dystonia (involuntary muscle contractions), tardive dyskinesia (repetitive, involuntary movements), parkinsonian symptoms (akinesia and tremors), and akathisia (motor restlessness or anxiety). 

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