A Textbook of Clinical Pharmacology and Therapeutics

114 SCHIZOPHRENIA AND BEHAVIOURAL EMERGENCIES

that atypical antipsychotics should be considered in newly
diagnosed schizophrenic patients and in those who have
unacceptable effects from, or inadequate response to, conven-
tional antipsychotic drugs. Risperidoneblocks D 2 , D 4 and in
particular 5HT 2 receptors. Careful dose titration reduces the
risk of adverse effects, but extrapyramidal side effects are com-
mon at high doses. It is available as an intramuscular injection
for acute control of agitation and disturbed behaviour. Weight
gain and, more worryingly, an increased incidence of stroke in
elderly patients with dementia have been reported wih both
risperidoneandolanzapine.Aripiprazoleis a long-acting
atypical antipsychotic which is a partial agonist at D 2 recep-
tors, as well as blocking 5HT 2. It is not associated with
extrapyramidal effects, prolactin secretion or weight gain.

treatment. The control of hypomanic and manic episodes with

chlorpromazineis often dramatic.

ACUTE PSYCHOTIC EPISODES

Patients with organic disorders may experience fluctuating

confusion, hallucinations and transient paranoid delusions.

Violent incidents sometimes complicate schizophrenic illness.

Key points

Pharmacological treatment

• Receptor blockade:
  –D 2 , D 4 , 5HT 2.


• Although there may be a rapid behavioural benefit, a
  delay (usually of the order of weeks) in reduction of
  many symptoms implies secondary effects (e.g. receptor
  up/downregulation).


• Conventional antipsychotics (e.g. chlorpromazine,
  haloperidol, fluphenazine), act predominantly by D 2
  blockade.


• Atypical antipsychotics (e.g. clozapine, risperidone,
  olanzapine) are less likely to cause extrapyramidal side
  effects.

Key points

Adverse effects of antipsychotic drugs

• Extrapyramidal motor disturbances, related to
  dopamine blockade.


• Endocrine distributions (e.g. gynaecomastia), related to
  prolactin release secondary to dopamine blockade.


• Autonomic effects, dry mouth, blurred vision,
  constipation due to antimuscarinic action and postural
  hypotension due to α-blockade.


• Cardiac dysrhythmias, which may be related to
  prolonged QT, e.g. sertindole (an atypical antipsychotic),
  pimozide.


• Sedation.


• Impaired temperature homeostasis.


• Weight gain.


• Idiosyncratic reactions;
  
  
  • jaundice (e.g. chlorpromazine);
  
  
  • leukopenia and agranulocytosis (e.g. clozapine);
  
  
  • skin reactions;
  
  
  • neuroleptic malignant syndrome.
  
  
  
  

BEHAVIOURAL EMERGENCIES

MANIA

Acute attacks are managed with antipsychotics, but lithium
is a common and well-established long-term prophylactic

MANAGEMENT

Antipsychotics and benzodiazepines, either separately or

together, are effective in the treatment of patients with violent

and disturbed behaviour. Lorazepamby mouth or parenteral

injection is most frequently used to treat severely disturbed

behaviour as an in-patient.

Haloperidol can rapidly terminate violent and psychotic

behaviour, but hypotension, although uncommon, can be

severe, particularly in patients who are already critically ill.

Doses should be reduced in the elderly.

Intramuscularolanzapineor liquid risperidoneare grad-

ually supplanting more conventional antipsychotics in the

acute management of psychosis.

When treating violent patients, large doses of anti-

psychotics may be sometimes needed. Consequently, extrapyra-

midal toxicity, in particular acute dystonias, develops in up to

one-third of patients. Prophylactic anti-parkinsonian drugs,

such as procyclidine, may be given, especially in patients who

are particularly prone to movement disorders.

The combination of lorazepam and haloperidol has

been successful in treating otherwise resistant delirious

behaviour.

Case history

A 60-year-old man with schizophrenia who has been

treated for 30 years with chlorpromazine develops involun-

tary (choreo-athetoid) movements of the face and tongue.

Question 1

What drug-induced movement disorder has developed?

Question 2

Will an anticholinergic drug improve the symptoms?

Question 3

Name three other drug-induced movement disorders

associated with antipsychotic drugs.

Answer 1

Tardive dyskinesia.

Answer 2

No. Anticholinergic drugs may unmask or worsen tardive

dyskinesia.

Answer 3

1.Akathisia.

2.Acute dystonias.

3.Chronic dystonias.

4.Pseudo-parkinsonism.