Gasser J C, Kaufman R D, Bellville J W
Clin Pharmacol Ther. 1975 Aug;18(2):170-4. doi: 10.1002/cpt1975182170.
The respiratory effects of a new benzodiazepine, lorazepam, were compared to those of pentobarbital and pentazocine. Pentobarbital, 50 and 150 mg, produced respiratory depression, as did pentazocine, 30 mg intramuscularly. Lorazepam at 1.33 and 4 mg intramuscularly produced none.