Cardiovascular effects of chronic phencyclidine (PCP) and ethanol in rats

Phencyclidine (PCP) and ethanol are widely abused either alone or in combination with each other. The present study evaluated the cardiovascular effects of acute and chronic PCP (10 mg/kg, s.c.) and ethanol (25% v/v) in male Sprague-Dawley rats (200-2508) over a six week period. Acute ethanol (25% v/v, ad libitum in drinking water for 24 hr) significantly reduced the presser response to PCP (+25+/-5 vs +9+/-2 mm Hg) without affecting heart rate (HR). Following indirect blood pressure (BP) measurement, neither PCP (108+/-4 vs 115+/-3 mm Hg) nor ethanol (103+/-2 vs 113+/-2 mm Hg) affected (BP) when given alone chronically. The combination of the two drugs significantly increased BP (107+/-6 vs 131+/-9, mmHg) and HR (314+/-10 vs 412+/-8 beat/min). PCP reduced water intake during the second week, whereas ethanol tended to increase water intake for the entire duration of the experimental period. The combination of PCP and ethanol significantly increased water intake during weeks 2 and 4. Urine output was enhanced by PCP at week 2 and suppressed by ethanol. Both PCP and ethanol decreased body weight, respectively. These data suggest that there is and an adverse cardiac ethanol PCP interaction.