Two consecutive, randomized, double-blind trials were performed to test the analgesic properties of a synthetic nitrogen analog of tetrahydrocannabinol (NIB). In the first trial, the test preparation was superior to placebo and approximately equivalent to 50 mg of codeine phosphate. In the second study, the tetrahydrocannabinol analog was superior to placebo and to 50 mg secobarbital. NIB is not useful clinically because of the frequency of side effects.