Antipsychotics
(Neuroleptics)
Dr.Balan Stephen
D2 receptor antagonists.
All neuroleptics share a dopamine receptor antagonism.
Of the many receptors identified, D2 effects are most important.
Indications
Psychotic reactions or illness
Non-alcoholic delirium
Behavioural problems in mental retardation and personality disorders
Low doses to treat bipolar depression with psychotic features
Tic disorders.
Classification of anti -psychotic drugs:
A). Typical or first generation antipsychotics.
Haloperidol, chlorpromazine, trifluperazine,
B). Atypical or second generation drugs
Rispiridon, olanzapine, amisulpiride,aripiprazole, quitiapine, clozapine,
Which drug to be chosen?
The anti-psychotic effects of different drugs are equal.it is important to avoid any side effects that may worsen the somatic disorder or increase the risk of complication.
Administration and dosage
Oral administration is the commonly used.in elderly and infirm patients; half the usual starting dose should be used. Most neuroleptics are metabolized by liver and excreted by kidney. Accordingly in patients with liver or kidney failure, dose reduction is required
Side-effects.
Neurologic side-effects
Akinetic syndrome
Parkinsonism
Akathisia
Acute dystonia
Tardive dystonia
Tardive dyskinesia
Vegetative and cardiovascular side-effects.
Anticholinergic syndrome
Dry mouth
Orthostatic hypotension
Prolonged qt interval
Endocrine and metabolic side effects
Weight gain
Lipid changes
Diabetes
Menstrual irregularities
Sexual side effects
Skin pigmentation-chlorpromazine
Blooddyscrasiasis-clozapine
Neuroleptic malignant syndrome
Antipsychotic in pregnancy
Trifluperazine, chlorpromazine, rispiridon, aripiprazole
In lactation
Amisulpiride
Parenteral antipsychotics
Haloperidol and olanzapine
Long acting depot injections
Fluphenazinedeconate, olanzapine available for patients with poor drug compliance.
Therapeutic Dosage
Haloperidol--- 5 to 20mg
chlorpromazine---- 100 to 400 mg
trifluperazine --- 5 to 20 mg
rispiridon 2 to 8 mg
olanzapine - 5 to 20 mg
amisulpiride ---- 50 to 8000 mg
clozapine --- 50 to 400 mg
aripiprazole --- 5 to 30 mg
qutiapine --- 50 to 400 mg
