From the Guidelines
Prazosin is the primary medication recommended for treating nightmares associated with PTSD, despite recent contradictory evidence, due to its established efficacy in reducing nightmare frequency and improving sleep quality in numerous studies, including a 2018 position paper by the American Academy of Sleep Medicine 1.
Medication Dosage and Administration
Typically, patients start with a low dose of 1-2mg at bedtime, gradually increasing to an effective dose of 3-15mg as needed, with the mean dose ranging from 3.1 mg to 15.6 mg in various studies 1. The medication should be taken 1-2 hours before bedtime with a small snack to improve absorption.
Mechanism of Action and Efficacy
Prazosin works by blocking alpha-1 adrenergic receptors, which reduces the norepinephrine activity that contributes to nightmares and hyperarousal symptoms in PTSD. Patients may notice improvement within days to weeks, but consistent use for at least 4-6 weeks is recommended to evaluate full effectiveness, as seen in a 15-week randomized controlled trial where prazosin was significantly superior to placebo for all three primary outcome measures 1.
Common Side Effects and Alternative Medications
Common side effects include dizziness, lightheadedness, and low blood pressure, particularly when standing up quickly. Other medications sometimes used include trazodone (50-200mg at bedtime), clonidine (0.1-0.3mg at bedtime), or certain atypical antipsychotics in resistant cases, as listed in a 2018 position paper by the American Academy of Sleep Medicine 1.
Importance of Trauma-Focused Psychotherapy and Regular Follow-up
These medications should be used alongside trauma-focused psychotherapy for best results, as medication alone may not address all aspects of PTSD. Regular follow-up with a healthcare provider is essential to monitor effectiveness and adjust dosing as needed, considering individual circumstances and accessible treatment options 1.
From the Research
Medications for Nightmares Associated with PTSD
- Prazosin has been shown to be effective in the treatment of PTSD trauma-related nightmares 2, 3, 4
- Other medications that have been studied for the treatment of PTSD nightmares include doxazosin, clonidine, tricyclic antidepressants, trazodone, mirtazapine, atypical antipsychotics (especially risperidone, olanzapine and quetiapine), gabapentin, topiramate, and cyproheptadine 2
- Novel agents such as ramelteon, cannabinoids, ketamine, psychedelic agents, and trihexyphenidyl have shown promising results, but large randomized controlled trials are needed to evaluate their use 2
- Medications that have been found to be ineffective for PTSD nightmares include venlafaxine, β-blockers, benzodiazepines, and sedative hypnotics 2
Dosage and Administration
- Prazosin should be initiated at 1 mg and then titrated upward until absence or desired reduction of nightmares is achieved, with a maximum dosage recommendation of 20 mg at bedtime and 5 mg midmorning 3
Clinical Experience
- A survey of Australian and New Zealand psychiatrists found that prazosin had been prescribed by 86% of respondents for PTSD-associated nightmares, with only 2% reporting it to be ineffective in reducing nightmare frequency and/or intensity 5
- A retrospective chart review found that five medications had 20 or more trials with successful results (partial to full nightmare cessation) in >50% of trials: risperidone, clonidine, quetiapine, mirtazapine, and terazosin 6