Chest Pain in a Young Patient Treated With Prazosin for PTSD

To The Editor: Prazosin is an a-1-adrenergic receptor antagonist that has been found to be effective in treating sleep-related posttraumatic stress disorder (PTSD) symptoms in three small parallel-group placebo-controlled studies (1, 2) . We report the case of a PTSD patient who developed chest pain following treatment with low-dose prazosin. Although not approved by the Food and Drug Administration, prazosin seemed to be a reasonable choice because of the patient’s prominent sleep difficulties.

The three controlled studies of prazosin in the treatment of PTSD patients (N=63) did not report any subjects with chest pain. The mean doses were 10 mg, 13 mg, and 3.1 mg (in a civilian trauma population), respectively. However, Medline Plus (3) lists chest pain as an adverse effect of prazosin. The incidence of patients who experience chest pain while being treated with prazosin could not be determined, although angina pectoris is listed as occurring in <1% of cases. In the present case, the temporal association of chest pain with the use of prazosin and the absence of a personal or family history of cardiac disease suggest a causal role of prazosin. However, the patient’s cardiac examination failed to demonstrate significant vulnerabilities, and thus it appeared that his symptom was a nonspecific chest pain. The pain apparently was not mediated by hypotension, which is a common side effect, especially in older patients with cardiovascular risk. In one review of long-term administration of prazosin (4), 30% of patients complained of dizziness, orthostatic hypotension, and/or palpitations. Hypotension can occur after the first dose, which is why the drug was started at only 1 mg in the three PTSD studies (1, 2) . Clinicians prescribing prazosin for the treatment of PTSD should be aware of the potential side effect of chest pain and its differential diagnosis.