Over a 31-day treatment period, patients received 5-, 7.5-, 10-, 15-, and 20-mg/kg/day doses of CBD. They received the highest dose on days 17–31. Patients had clinic visits at screening, baseline, and after the 31-day treatment period. Of the 13 patients enrolled, one failed the screening visit, another patient did not start the study drug, and another patient was on the study drug for two days. The 10 remaining patients were included in the adverse events analysis. Adverse events were mostly mild to moderate and included fatigue, diarrhea, somnolence, elevated liver enzymes, and dizziness. Three of the 10 patients dropped out of the study due to intolerance. One of the three patients had an allergic reaction and two had abdominal pain. There were no serious adverse events.
Among the seven patients who completed the treatment period and were included in the efficacy analysis, mean total UPDRS score significantly decreased from 45.9 at baseline to 36.4 at the final visit. UPDRS motor score significantly decreased from 27.3 to 20.3. Mean rigidity subscore significantly decreased from 9.14 to 6.29. In addition, data hinted that CBD treatment might have reduced pain and irritability, the researchers said.