Lethality of pentazocine and tripelennamine combinations in mice housed individually and in groups.

Lethality of 80 mg/kg pentazocine alone; 40 mg/kg tripelennamine alone; 20 mg/kg tripelennamine in combination with 40, 60, and 80 mg/kg pentazocine; and 40 mg/kg tripelennamine in combination with 10, 20, and 40 mg/kg pentazocine was determined in mice housed individually and in groups. Results indicate that the lethality of pentazocine and tripelennamine combinations in mice is (1) dose-dependent, (2) potentiated relative to either drug alone, and (3) greater in group-housed than in individually-housed animals.