Propranolol Antagonizes Phencyclidine-Induced Hyperactivity and Stereotypy in Rats

The single and combined effects of acute phencyclidine (PCP) and propranolol, each given intraperitoneally, were studied on rat behavior. PCP (5, 10, 25, 50, and 100 mg/kg) produced dose-related stereotypy and increases in (photocell) hyperactivity over 4 h observation. Propranolol (10 and 25 mg/kg) neither caused any stereotypy nor had any effect on activity relative to vehicle control. Additionally, propranolol (10 and 25 mg/kg), given 30 min after PCP (10, 25 and 50 mg/kg), reduced or completely blocked the stereotypy and hyperactivity caused by PCP. These data provide the first experimental verification of a clinical observation that propranolol may be an effective antagonist of the behavioral toxicity produced by PCP.