THE EFFECT OF CYPROHEPTADINE AND/OR BROMOCRIPTINE ON PLASMA ACTH LEVELS IN PATIENTS CURED OF CUSHING'S DISEASE BY BILATERAL ADRENALECTOMY

Cyproheptadine and bromocriptine have been reported to be therapeutic in suppressing ACTH levels in Cushing's disease and Nelson's syndrome. However, there have been only scattered reports of their effect in suppressing raised ACTH levels found in patients cured of Cushing's disease by bilateral adrenalectomy. In order to assess whether these agents could prove beneficial in such patients we studied 12 patients previously treated with bilateral adrenalectomy alone for Cushing's disease before and after 3 weeks of cyproheptadine and/or bromocroptine therapy. All had raised plasma ACTH values but no patient had evidence of a pituitary macroadenoma. Plasma ACTH and cortisol were sampled 2‐hourly for 24 h. Neither drug regime led to any change in plasma levels of cortisol for 24 h after a 20 mg dose of oral hydrocortisone. Plasma ACTH (mean±SEM) showed a small but significant overall reduction (523±45 vs 392±34 ng/1; P < 0.05) while on bromocriptine alone (5 mg given at 0800 and 1800 h, n=5). When each time point was analysed individually this reduction was significant at only five out of 13 time points. At 0400 h plasma ACTH (mean±SEM) was 7584±298.1 vs 380.2±166.6; 0600 h, 795±288.7 vs 477.8±191.7; 1200 h, 266.8±106.2 vs 187.0±80.3; 1400 h, 470.0±239.0 vs 302.0±135.9; 1600 h, 548.6±262.5 vs 394.2±178.5 ng/1 (P < 0.05). There was no significant change in plasma ACTH during treatment with the combination of bromocriptine and cyproheptadine. These results do not support the routine use of these agents for patients with raised ACTH levels after bilateral adrenalectomy for Cushing's disease.