The analgesic properties of delta-9-tetrahydrocannabinol and codeine.

The administration of single oral doses of delta-9-tetrahydrocannabinol (THC) to patients with cancer pain demonstrated a mild analgesic effect. At a dose of 20 mg, however, THC induced side effects that would prohibit its therapeutic use including somnolence, dizziness, ataxia, and blurred vision. Alarming adverse reactions were also observed at this dose. THC, 10 mg, was well tolerated and, despite its sedative effect, may analgesic potential.