Perioperative vasopressin secretion treated by demeclocycline

The purpose of this study was to evaluate the perioperative effects of demeclocycline on vasopressin (VP) in patients undergoing surgery, specifically coronary artery bypass grafting (CABG). This was a prospective, double-blind placebo-controlled clinical study using human subjects in a 575- bed tertiary care teaching community hospital. Thirty patients (20 males and 10 females) undergoing elective CABG over a 6-month period were randomized preoperatively to receive either demeclocycline or a placebo. Each patient received either a total of 1200 mg daily of demeclocycline or a placebo beginning 5 days preoperatively and continuing through postoperative day 2. Urine and serum osmolality, electrolytes, and VP levels were measured daily. Perioperative VP levels were significantly higher (P = 0.05) in the demeclocycline group despite decreased VP activity. The postoperative serum sodium and osmolality remained normal in the demeclocycline group and significantly decreased in the placebo group (P < 0.01). The urine osmolality increased significantly in the placebo group (P = 0.04) on postoperative day 1. We conclude that perioperative administration of demeclocycline reliably inhibits the effects of increased VP secretion commonly seen in patients undergoing CABG procedures. Applying these findings to surgical patients who are at increased risk of complicated fluid and electrolyte problems requires further study.