Olanzapine's Effect on Nightmares

Evidence for Olanzapine's Effect on Nightmares

• The American Academy of Sleep Medicine guidelines indicate that olanzapine has been studied as a treatment for nightmares rather than a cause of them, with a small case series of 5 patients with combat-related PTSD showing rapid improvement of nightmares with no adverse events reported when olanzapine 10-20 mg was added to existing treatment 1
• The American Academy of Sleep Medicine guideline classifies atypical antipsychotics, including olanzapine, as medications that "may be considered for treatment of PTSD-associated nightmares," though the data quality is acknowledged as "low grade and sparse" 1, 2

Important Clinical Context

• Comorbid PTSD or trauma history may manifest as nightmares in patients with schizophrenia or bipolar disorder, and this should be considered when evaluating nightmares in these patients 1, 2
• Other medications, including many psychotropic drugs, can affect sleep architecture and dream content, and should be reviewed when evaluating nightmares in patients taking olanzapine 1, 3

Management Approach if Nightmares Occur

• Adding prazosin 1 mg at bedtime, titrating to 10-16 mg, can reduce nightmare frequency from approximately 4 nights/week to 1-2 nights/week 4
• Trazodone 50-100 mg at bedtime can be added if insomnia coexists with nightmares, reducing nightmare frequency from 3.3 to 1.3 nights/week 4