2.4. Randomization
Electronic selection by computer was used to divide patients into blocks with a total of 5 groups with around 25 patients in each one. Group 1 received Vit C, group 2 Vit E, group 3 NAC and group 4 MT; group 5 patients remained without treatment (Tx) and formed the control group. Personnel unrelated to the study participated in the blinding and placed the indicated therapy in identical opaque envelopes numbered from 1 to 125 and these were applied consecutively. The randomized process is shown in 