Drug Therapy

Drug therapy in the management of delirium should be avoided, if possible. Sedation may be required in the following situations [2]:

  • To carry out essential investigations or treatment
  • To prevent the patients endangering themselves or others
  • To relieve distress in a highly agitated or hallucinating patient


If drug treatment is necessary

If drug treatment is necessary, haloperidol is the current initial medication of choice. An appropriate starting dose would be 0.5-1 mg, administered orally or IM, with regular reassessment and titration up to a maximum of 5mg. It is best to avoid haloperidol in reduced GCS or clinical significant cardiac conditions.

There is no evidence to support the use of newer antipsychotic medications (e.g. olanzapine, risperidone) in the management of delirium [12].

Side effects

Side effects include extrapyramidal symptoms, which patients experience from dopamine-receptor blocking agents such as the first-generation antipsychotics haloperidol and phenothiazine neuroleptics [13]. For this reason, haloperidol should be avoided in patients with Parkinson’s or Lewy body dementia.

The symptoms of extrapyramidal side effects are debilitating and affect mobility, communication and day-to-day activities [13].

Regular electrocardiography (ECG) monitoring should be performed to ensure that the QT interval does not become prolonged.

For delirium due to alcohol withdrawal, or those not suitable for haloperidol, a benzodiazepine would be suitable. Lorazepam, at an initial dose of 2 mg (IM/IV), with regular reassessment and titration to effect, is preferred.