Switching from Trazodone to Mirtazapine for PTSD-Related Nightmares
No, switching from trazodone to mirtazapine (Remeron) is not recommended for PTSD-related nightmares, as mirtazapine lacks specific evidence for nightmare reduction and is not mentioned in American Academy of Sleep Medicine guidelines for this indication, whereas trazodone has demonstrated 72% efficacy in reducing nightmare frequency. 1, 2
Evidence Against Mirtazapine for Nightmares
- Mirtazapine is FDA-approved only for major depressive disorder, with no established efficacy for PTSD-related nightmares or sleep disturbances specific to trauma 3
- The American Academy of Sleep Medicine position paper on nightmare disorder does not recommend mirtazapine as a treatment option for PTSD-associated nightmares, despite reviewing multiple pharmacological agents 4, 2
- While mirtazapine has been mentioned in narrative reviews as having "evidence of varying quality" for post-traumatic nightmares, no controlled trials support its use for this specific indication 5
Evidence Supporting Continued Trazodone Use
- Trazodone reduced nightmare frequency from 3.3 to 1.3 nights per week (72% response rate) in veterans with PTSD, with an effective dose range of 50-200 mg nightly for 70% of patients 1, 2, 6
- The American Academy of Sleep Medicine specifically lists trazodone as a recommended option for PTSD-associated nightmares, with mean effective doses of 212 mg 2
- 92% of patients reported improved sleep onset and 78% reported improved sleep maintenance with trazodone 6
When to Consider Switching from Trazodone
Switch from trazodone only if the patient experiences intolerable side effects or inadequate response after optimizing the dose to 200-600 mg nightly. 1, 2
Specific reasons to discontinue trazodone:
- Development or worsening of vivid nightmares (occurs in approximately 1.4% of patients) 1
- Priapism (reported in 12% of PTSD patients, higher than expected) 1, 6
- Severe daytime sedation or dizziness (affects 60% but usually tolerable) 1
- Orthostatic hypotension, particularly in elderly patients 1, 3
Recommended Alternative Medications (Not Mirtazapine)
If trazodone fails or is not tolerated, follow this evidence-based algorithm: 7, 2
First-line alternative: Prazosin
- Start 1 mg at bedtime, titrate by 1-2 mg every few days 2
- Effective doses: 3-4 mg/day for civilians, 9.5-15.6 mg/day for military veterans 2
- Most established pharmacological option with strongest evidence 2
Second-line alternative: Clonidine
- Start 0.1 mg twice daily, titrate to 0.2 mg/day average dose 7
- Reduced nightmares in 11/13 patients in case series 2
- Similar mechanism to prazosin (reduces CNS adrenergic activity) 7
Third-line alternative: Risperidone
- Start 0.5-2.0 mg at bedtime 7, 2
- 80% of patients report improvement after first dose 7
- Effective at substantially lower doses than needed for psychotic disorders 7
Critical Pitfalls to Avoid
- Do not use clonazepam or venlafaxine - both have shown no improvement over placebo in controlled trials 7, 2
- Do not use benzodiazepines - may worsen PTSD symptoms and promote dependence 8
- Monitor blood pressure carefully with prazosin, clonidine, and trazodone due to hypotensive effects 2
- Avoid nefazodone as first-line therapy due to hepatotoxicity risk 7
- Screen for substance use interactions given this patient's history of substance use disorder 9
Mirtazapine-Specific Concerns
- Significant weight gain: 49% of patients gain ≥7% body weight (compared to 5.7% with placebo) 3
- Marked somnolence: 54% experience sedation (vs 18% placebo), leading to 10.4% discontinuation rate 3
- Increased appetite in 17% of patients 3
- No evidence base for nightmare reduction in PTSD populations 4, 2, 3