Take-home points

Acute onset of mental status changes within hours is often drug-induced or a medical delirium

Confusion and a waxing of consciousness is usually not associated with other major psychiatric disorders

Consultation and liaison between multiple providers is often needed to successfully diagnose and treat the medical and psychiatric components of delirium

Performance in practice: confessions of a psychopharmacologist

What could have been done better here?

• – Not sure; this case was fairly successful

  • Every now and then, clinicians do things correctly the first time

Possible action items for improvement in practice

• – Research the diagnosis and treatment of delirium in guidelines, review articles, or textbooks

• – Even psychiatrists and psychopharmacologists who do not typically specialize in the interface of psychiatry and internal medicine, called “consultation-liaison psychiatry,” may be asked to consult on behalf of their outpatients in similar fashion

  • This type of information is covered on psychiatric board recertification examinations for all psychiatrists!

• – Research typical dosing strategies for both typical and atypical antipsychotics when treating delirium, as dosing is often with lower doses and for shorter durations

• – Become aware of psychotropics that are prone to intoxication effects or withdrawal effects that can mimic delirium

• – Realize that medically or surgically admitted patients may have their psychotropics discontinued, setting them up for withdrawal delirium

Tips and pearls

Haloperidol (Haldol) is considered the gold standard antipsychotic for use in behavioral management of delirium

It is a clean drug in that it has very little pharmacodynamic properties outside D2 receptor antagonism

• – There is little to no antihistamine sedation to cloud the mental state further

• – There is little to no anticholinergic potential as far as worsening memory or increasing delirious psychotic features

It can be given orally or with an IM injection

It should not be given directly via IV push, as it is known to prolong QTc intervals and place patients at risk for ventricular arrythymia. A slow IV drip may be used with appropriate cardiac monitoring in rare cases

Guidelines suggest obtaining pre- and post-antipsychotic initiation EKGs, as many typical and atypical antipsychotics prolong QTc intervals in these already compromised medical patients

Atypical antipsychotics may be used as they have lower EPS rates, but have less of an evidence base regarding dosing

• – Risperidone (Risperdal) likely has the most supporting data

• – The high-potency typical antipsychotic haloperidol (Haldol) may cause akathisia, which may appear as delirium agitation worsening and lead to a reflexive increase in haloperidol to treat the agitation, further causing more EPS

  • The atypical antipsychotics have less likelihood of akathisia and may be favored for this reason

• – However, the atypical antipsychotics are not as selective in that they often have marked pharmacodynamic properties outside D2 receptor antagonism, which may cloud or alter the mental state further

  • For example, olanzapine (Zyprexa) has anticholinergic properties

  • Quetiapine has antihistamine properties

The risk of TD is minimal as delirium is often treated for a few days to a few weeks at most, using doses lower than that used to treat schizophrenia

Two-minute tutorial