Endocrine Abstracts

Background: Demeclocycline is a well-known treatment for syndrome of inappropriate ADH secretion (SIADH). We studied the use of demeclocycline for treatment of SIADH in our hospital to assess its efficacy and safety.

Materials and methods: A search was performed for all discharge summaries containing demeclocycline over period of 1 year. 40 results obtained of which five were excluded as demeclocycline was mentioned but not actually used. 35 admission episodes involving 27 unique patients were identified. 18 episodes excluded as they were on demeclocycline prior to admission. Data analysed for 17 episodes where demeclocycline was started in the current admission.

Results: Of the 17 episodes, prescription data was not available for two episodes and in one episode the use was transient (<5 days). The results showed that the mean rise in sodium level at day 5 was >3.1 mmol/l (data from seven patients) and the peak rise in sodium was at day 7 of >6 mmol/l (data from five patients). Two patients failed to show any significant response despite prolonged demeclocycline (>14 days). Three patients had to discontinue demeclocycline due to significant renal impairment.

Conclusions: Demeclocycline, though effective in the management of SIADH has a variable effect on sodium level, no significant change is observed in the first 72 h. In patients who respond, significant rise in Na is usually seen in 5–7 days. It is safe to initiate in an outpatient setting but serum Na should be monitored at 1, 2 and 4 weeks following initiation. It should be discontinued if significant renal impairment and/or hypernatremia develops.