The No-Effect Level of Sodium Bromide in Healthy Volunteers

Abstract

1 A total of 0, 4 and 9 mg kg^-1 body weight sodium bromide was administered orally to 45 healthy female volunteers.

2 The experiment lasted for six menstrual cycles: only during the first three cycles was bromide administered;

3 At the start, at the end of the administration period and at the end of the experiment a physical examination and haematological and routine clinical chemistry tests were performed. Except for nausea in relation to the intake of bromide, no adverse effects were observed.

4 The bromide concentration in plasma rose to 3.22 ± 0.93 mmol kg^-1 in the 4 mg kg^-1 group and to 7.99 ± 1.89 in the 9 mg kg^-1 group by the end of the administration period.

5 Before and at the end of the experiment the thyroid hormones (T₄, FT₄, TBG, T3 and TSH) were analysed. No significant differences were observed between the groups.

6 Before, after three menstrual cycles and at the end of the experiment an EEG with a Visual Evoked Response was recorded. At the 4 and 9 mg kg^-1 dose level in the α₁-band and the β-bands significant changes were found (P < 0.1 and P < 0.05, respectively). The Visual Evoked Response showed no significant differences between the three groups.

7 From this experiment and previous experiments a no-effect level in humans for sodium bromide of 4 mg kg^-1 body weight is proposed.