Fluid Retention Produced by Guanethidine; Changes in Body Exchangeable Sodium, Blood Volume, and Creatinine Clearance.

IN a previous paper,1 the clinical features of fluid retention complicating the use of guanethidine were discussed. Of 134 patients treated continuously for over a year, 44 (32.8 per cent) were observed to retain fluid and yet, comparing these with the 90 who apparently avoided the complication, no significant differences could be found in respect to age, previous renal disease, change in the frequency of micturition, or abnormality of the electrocardiogram. Although women preponderated among those developing fluid retention and there was a significant proportion of patients who had previously experienced edema in the fluid-retaining group, neither of these factors could account completely for the incidence of fluid retention. It seemed likely that either the distinguishing factor between the two groups had been overlooked or no such factor existed and retention of fluid was a potential hazard for all patients treated with guanethidine. In order to test the hypothesis that fluid retention is a potential risk in all patients treated, 12 patients given guanethidine and three treated with reserpine were selected for study during the first 12 months of their hypotensive treatment.