Can Quetiapine (Seroquel) cause hallucinations and confusion?

Quetiapine (Seroquel) and Its Relationship to Hallucinations and Confusion

Quetiapine (Seroquel) can cause hallucinations and confusion as adverse effects, particularly in elderly patients or those with pre-existing cognitive impairment, and these symptoms are recognized clinical features of drug-induced delirium. 1

Mechanism and Clinical Presentation

Quetiapine is an atypical antipsychotic commonly used to treat schizophrenia, bipolar disorder, and other psychiatric conditions. While it's designed to treat psychotic symptoms, it can paradoxically cause or worsen cognitive disturbances in certain populations:

• Delirium features: Quetiapine-induced cognitive disturbances may present with:

  • Perceptual disturbances including hallucinations (usually visual or tactile)
  • Confusion and disorientation
  • Impaired attention and awareness
  • Disorganized thought processes
  • Language disturbances
  • Sleep-wake cycle disturbances 1

• Presentation patterns: Symptoms may follow:

  • Rapid development (hours to days)
  • Fluctuating severity throughout the day (often worse in evening/night)
  • Varying psychomotor patterns (hyperactive, hypoactive, or mixed) 1

Risk Factors

Several factors increase the risk of quetiapine-induced hallucinations and confusion:

• Age: Elderly patients are particularly vulnerable due to age-related changes in brain neurochemistry and drug metabolism 2
• Polypharmacy: Concurrent use of multiple medications with anticholinergic properties
• Dosing issues: Rapid dose escalation or excessive dosing
• Medical comorbidities: Especially electrolyte disturbances, infections, or brain metastases 1
• Pre-existing cognitive impairment: Patients with dementia or other neurological disorders

Management Approach

When hallucinations and confusion occur with quetiapine:

1. Recognize the symptoms: Use standardized assessment tools like the Confusion Assessment Method (CAM-ICU) to identify delirium 1

2. Address reversible causes:

   • Consider drug-induced delirium as a potential cause
   • Evaluate for other contributing factors (electrolyte disturbances, infections, etc.) 1

3. Medication management:

   • Reduce or discontinue quetiapine if it's suspected as the cause
   • Consider dose reduction rather than complete discontinuation if quetiapine is essential for treatment
   • Avoid abrupt discontinuation to prevent withdrawal symptoms 3

4. Alternative management:

   • If antipsychotic treatment is still needed, consider switching to a different agent with lower risk of cognitive side effects
   • For severe agitation with hallucinations, haloperidol may be considered at 0.5-1 mg initially (maximum 5 mg/day) 3

Prevention Strategies

To minimize the risk of quetiapine-induced hallucinations and confusion:

• Start low, go slow: Begin with low doses (especially in elderly) and titrate gradually
• Regular monitoring: Assess for early signs of cognitive changes
• Medication review: Minimize polypharmacy, especially anticholinergic burden
• Patient education: Inform patients and caregivers about potential symptoms to report

Important Considerations

• While quetiapine is often considered to have a relatively benign side effect profile compared to conventional antipsychotics 4, cognitive disturbances remain a significant concern, particularly in vulnerable populations
• Paradoxically, quetiapine is sometimes used to treat delirium, yet it can itself cause delirium-like symptoms
• The risk of cognitive side effects must be balanced against the benefits in treating the underlying psychiatric condition
• Symptoms typically resolve with dose reduction or discontinuation, but may persist longer in elderly patients 1

By recognizing the potential for quetiapine to cause hallucinations and confusion, clinicians can monitor patients appropriately and intervene promptly when these adverse effects occur.