Table 1.

Included randomised controlled trials – study design

Author, year [study name]	Patient population	Study design	Eligibility criteria	Interventions	Study outcomes	Demeclocycline dose
Alexander et al. 1991 24	Nine psychiatric patients (six male), aged 31–47 years (mean, 38.3 years), with polydipsia‐HN	Randomised, double‐blind, placebo‐controlled cross‐over trial	Chronic psychiatric illness and documented episodic or chronic HN (< 135 mmol/l) associated with polydipsia	Demeclocycline or placebo Stable daily doses of neuroleptics	Body weight; serum sodium levels; number of episodes of sodium levels <125 or < 135 mmol/l	300 mg for 3 weeks (twice daily for 7 days; three times daily for 7 days; four time daily for 7 days)
Horattas et al. 1998 25	Thirty patients (20 male), aged 40–70 years (mean, 61.4 years), undergoing elective coronary artery bypass grafting	Randomised, double‐blind, placebo‐controlled clinical study	Normal electrolytes and renal function Exclusions: renal or hepatic dysfunction; endocrine abnormalities; pregnancy; recent antibiotic use; hypersensitivity to tetracycline	600 mg DMC or placebo twice daily, beginning 5 days pre‐operatively and continuing through postoperative day 2 Pain medication and/or antihypertensives	Serum electrolytes; complete blood counts; prothrombin time; partial thromboplastin time; arterial blood gases; urine electrolytes; osmolality; serum vasopressin	600 mg (twice daily) from day 5 pre‐operation to day 2 post operation

DMC, demeclocycline; HN, hyponatraemia.