How do Seroquel (quetiapine) and Ativan (lorazepam) compare in terms of inducing confusion?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: October 15, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Seroquel vs. Ativan: Comparison of Confusion Side Effects

Quetiapine (Seroquel) is more likely to cause confusion than lorazepam (Ativan), particularly in elderly patients and those with respiratory conditions.

Comparison of Confusion Risk

Quetiapine (Seroquel)

  • Quetiapine has been associated with significant confusion and cognitive impairment, particularly in vulnerable populations 1
  • In clinical studies, quetiapine demonstrated a high likelihood of causing confusion, with common side effects including dizziness, somnolence, and cognitive impairment 1
  • A case study reported severe confusion when quetiapine was combined with other medications, indicating its potential for significant cognitive side effects 2
  • Quetiapine has been associated with respiratory dysfunction that can lead to confusion, particularly in patients with sleep apnea syndrome 3

Lorazepam (Ativan)

  • Lorazepam can cause confusion but is generally better tolerated from a cognitive perspective when used appropriately 4
  • When used for alcohol withdrawal, lorazepam should be carefully dosed (0.5-1 mg orally four times daily as needed) to minimize confusion risk 4
  • Paradoxical agitation, which can include confusion, occurs in approximately 10% of patients treated with benzodiazepines like lorazepam 4
  • Lower doses (0.25-0.5 mg) are recommended in older or frail patients to reduce confusion risk 4

Risk Factors for Increased Confusion

Patient-Specific Risk Factors

  • Elderly patients are at significantly higher risk for medication-induced confusion with both medications 5
  • Patients with renal or hepatic dysfunction are at increased risk for confusion with either medication 6
  • Patients with respiratory conditions, particularly sleep apnea, may experience severe confusion with quetiapine 3
  • Patients taking multiple medications are at higher risk for confusion with either medication 5

Drug Interaction Considerations

  • Quetiapine combined with benzodiazepines like lorazepam can significantly increase confusion risk and respiratory depression 3
  • Quetiapine interacts with multiple medications including phenytoin, carbamazepine, and barbiturates, which may alter its effects and confusion potential 1
  • Lorazepam should be used with caution when combined with antipsychotics due to potential for increased confusion and sedation 4

Clinical Management Recommendations

Dosing Considerations

  • For quetiapine, the optimal treatment dose is 300-400 mg/day in divided doses, but lower doses should be considered in patients at risk for confusion 1
  • For lorazepam, use 0.5-1 mg orally four times daily as needed (maximum 4 mg in 24 hours) to minimize confusion risk 4
  • In elderly patients, start with lower doses of either medication and titrate slowly to reduce confusion risk 4, 5

Monitoring

  • Regularly assess cognitive function when initiating either medication, particularly in high-risk patients 5
  • Monitor for respiratory dysfunction, especially when quetiapine is used in obese patients or those with sleep apnea 3
  • Be vigilant for confusion as an adverse effect when either medication is newly prescribed, particularly in elderly patients 5

Special Considerations

Elderly Patients

  • Physiological changes in elderly patients affect medication pharmacodynamics and increase confusion risk with both medications 5
  • Lower starting doses and more careful monitoring are essential in this population 4, 5
  • Quetiapine poses a particularly high risk of confusion in elderly patients compared to lorazepam when appropriately dosed 1, 5

Patients with Respiratory Conditions

  • Quetiapine has been associated with severe respiratory dysfunction and subsequent confusion in patients with sleep apnea 3
  • The combination of quetiapine and lorazepam can lead to respiratory failure and coma in vulnerable patients 3
  • Respiratory function should be carefully monitored when using quetiapine in patients with possible sleep apnea 3

References

Research

Quetiapine: a new atypical antipsychotic.

South Dakota journal of medicine, 1998

Guideline

Management of Lorazepam in Alcohol Withdrawal with Agitation

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.