Review of Pharmacology - 9E (2015)

Central Nervous System
According to their potential to cause adverse metabolic side effects, anti-psychotics can
be classified as:
High Potential:
Intermediate potential:
Low Potential:
Least potential:
Clozapine, Olanzapine
Quetiapine
Risperidone, Paliperidone
Ziprasidone, Aripiprazole, Iloperidone,Asenapine
• Retinal degeneration with thioridazine.
• Agranulocytosis with clozapine.
• Cataract formation with quetiapine.
• Cholestatic jaundice with chlorpromazine.
• Dry mouth, blurred vision, constipation, urinary retention (due to anticholinergic
effects; maximum with thioridazine).
• Hyperprolactinemia, amenorrhoea and galactorrhoea (due to D 2
blockade in
pituitary).
• Extrapyramidal symptoms (due to D 2
blockade in limbic system) are closely related
to antipsychotic potency of typical antipsychotic drugs
Other Uses
v Acute muscular dystonia: It is the earliest appearing symptom (within hours)
and may manifest as torticollis, locked jaw, oculogyric crisis or spasm of other
muscles. Central anticholinergics are useful in the treatment.
v Parkinsonism: It appears between 1-4 weeks of therapy. Central anticholinergics
like benzhexol are drug of choice for drug induced Parkinsonism
v Akathisia: It is an irresistible desire to move about in the absence of anxiety.
It is the most common extrapyramidal symptom. Cigarette smoking is
associated with increased risk of akathisia. Propanolol is the preferred drug
for this condition; however central anticholinergics are also useful in the
treatment.
v Malignant neuroleptic syndrome: It presents as hyperthermia, extreme
generalized rigidity, autonomic instability and altered mental status. It can be
treated by i.v. dantrolene (DOC) or bromocriptine.
v Tardive dyskinesia: It occurs late in therapy and is characterized by
purposeless involuntary movements like chewing or puffing of cheeks. There
is no satisfactory treatment for this condition; however, central anticholinergics
are contraindicated.
tahir99 - UnitedVRG
• These agents can be used as an alternative to ECT in severe depression with psychotic
features.
• Alcoholic hallucinosis.
• Gilles de la Tourette’s syndrome and Huntington’s disease (Haloperidol is drug of
choice).
Use of antipsychotics
Anti-emetics
Psychosis
Chorea
TIC disorders
(Gille de la
Torrette
anti psy cho tic syndrome)
General Central Nervous Pharmacology System
Note:
1. Haloperidol and fluphenazine are most potent typical antipsychotic drugs whereas risperidone
is most potent atypical antipsychotic agent.
2. Risk of extrapyramidal adverse effects is negligible with clozapine, quetiapine and aripiprazole.
3. Chlorpromazine, thioridazine and clozapine possess strongest anticholinergic activity.
4. Fluphenazine (enanthate and decanoate) and haloperidol (decanoate) are long-acting injectable
(s.c. or i.m) forms of typical antipsychotics. Risperidone is the first atypical antipsychotic
available in long-acting injectable form.
5. Most commonly used antipsychotic by intravenous route is haloperidol
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