Cycloserine could show similar effects for PTSD, said Michael Davis, Ph.D., professor of psychiatry and behavioral sciences at Emory University, Atlanta. “I–m not sure how good propranolol will be in the long run,” he said. “If you're trying to get rid of really traumatic fear memories, you need something to block not only the active recollection [of the event], but also the associated fear.
Small Studies of Propranolol Set Scene
Dr. Pitman's initial study of propranolol is one of two small pilot studies that looked at use of the drug shortly after a traumatic event.
Forty-one patients were randomized in the emergency department at Massachusetts General Hospital to begin—within 6 hours of a traumatic event—a 10-day course of propranolol (40 mg four times daily) or placebo. Eighteen of the 41 received propranolol.
Patients in the double-blind study were instructed to return 1 and 3 months later for assessment with the Clinician-Administered PTSD Scale (CAPS). At the 3-month follow-up, investigators also measured patients' physiologic responses during script-driven imagery of the traumatic event.
At 1 month, the PTSD rate was 30% in the placebo group (6 of 20 patients who returned for follow-up) and 18% (2 of 11 who returned) in the propranolol group. At 3 months, the CAPS scores did not differ. However, the psychophysiologic testing results suggested that propranolol had an impact. None of the 8 propranolol patients who participated, but 6 of the 14 participating placebo patients, were physiologic responders, reported Dr. Pitman and his associates (Biol. Psychiatry 2002;51:189–92).
In a second, nonrandomized study of patients treated in the emergency departments of two hospitals in France, 11 patients received propranolol for 7 days (40 mg three times daily), with the first dose administered 2–20 hours after the trauma and with a taper period of 8–12 days; they were compared with 8 patients who refused propranolol but agreed to participate.
PTSD rates, as well as PTSD symptom scores, were higher in the patients who refused the drug (3 of 8) than in patients who took it (1 of 11), reported Guillaume Vaiva, M.D., of the University of Lille (France), and his associates (Biol. Psychiatry 2003;54:947–9).
“The French study showed a significant reduction of PTSD symptoms—we only found a significant trend,” Dr. Pitman said.