6.5.2.2 Antidiuretic hormone antagonists

ChoiceDrugDosage
Formulary choice

Demeclocycline capsules 150mg

Prescribe under specialist supervision

Dose:
initially 0.9-1.2g daily in divided doses; maintenance 600-900mg daily

Prescribing Notes

  • Demeclocycline is indicated for chronic syndrome of inappropriate secretion of anti–diuretic hormone (SIADH) only where fluid deprivation alone does not restore sodium concentration or is not tolerable. However, use of demeclocycline is limited by side effects, e.g. photosensitivity, extreme nausea and renal toxicity.
  • Demeclocycline has a variable and unreliable time to onset of action.
  • Patients receiving demeclocycline must be closely monitored.
  • Higher doses of demeclocycline may be associated with a decline in glomerular filtration. Creatinine should be monitored along with plasma sodium.