From the Guidelines
It is not recommended to prescribe tamsulosin and prazosin together for a patient with PTSD nightmares and enlarged prostate due to the potential for additive side effects and increased risk of hypotension, dizziness, and syncope. When considering treatment for a patient with both conditions, it is essential to weigh the benefits and risks of each medication. Prazosin, as noted in the 2018 position paper 1, has been shown to be effective in treating PTSD-related nightmares, with a mean dose of 13 ± 3 mg/day, and has also provided some benefit for urinary symptoms of benign prostatic hyperplasia (BPH). Alternatively, tamsulosin, as discussed in the 2003 AUA guideline 1, is more selective for the prostate and may better control urinary symptoms, but it has less evidence for PTSD nightmares. Some key points to consider when choosing between these medications include:
- The potential for orthostatic hypotension, dizziness, and syncope, particularly with prazosin, as first-dose hypotension can occur
- The need for blood pressure monitoring when initiating either medication
- The possibility of using alternative medication classes, such as a 5-alpha reductase inhibitor (finasteride or dutasteride) for BPH or an alternative psychiatric medication for PTSD, if symptoms of either condition remain inadequately controlled with a single agent. Given the potential risks and benefits, prazosin (starting at 1mg at bedtime and gradually increasing to 3-15mg as tolerated) may be a suitable option for patients with both PTSD nightmares and enlarged prostate, as it has evidence for treating PTSD-related nightmares and some benefit for urinary symptoms of BPH.
From the Research
Tamsulosin and Prazosin for PTSD Nightmares and Enlarged Prostate
- The provided studies do not directly address the use of tamsulosin and prazosin together for PTSD nightmares and enlarged prostate 2, 3, 4, 5, 6.
- Tamsulosin is primarily used to treat benign prostatic hyperplasia (BPH) and has been shown to be effective in improving symptoms and peak urine flow relative to placebo 2, 5, 6.
- Prazosin is an alpha-1 adrenergic receptor antagonist that has been used to treat PTSD nightmares, but its use in combination with tamsulosin for this purpose is not supported by the provided evidence.
- The safety profile of tamsulosin has been evaluated in various studies, and it has been found to be generally well-tolerated, with common adverse events including dizziness, abnormal ejaculation, and orthostatic hypotension 2, 3, 4, 5, 6.
- There is no evidence to suggest that tamsulosin would interact negatively with prazosin, but the combination of these two medications for PTSD nightmares and enlarged prostate is not supported by the provided studies.
Potential Interactions and Safety Considerations
- The coadministration of tamsulosin with other antihypertensive agents has been evaluated, and it has been found to have a favorable safety profile 3.
- However, the use of tamsulosin in combination with prazosin, which is also an alpha-1 adrenergic receptor antagonist, may increase the risk of hypotension and other adverse events.
- Further studies are needed to evaluate the safety and efficacy of combining tamsulosin and prazosin for PTSD nightmares and enlarged prostate.