Renal pharmacodynamics of lithium and amiloride in healthy volunteers

INTERVENTION: From day 2, volunteers will receive either oral tablets of lithium 250mg or 500mg/day for 8 weeks. In addition, during weeks 5‐6, they will also receive oral tablets of amiloride 5mg/day, and during weeks 7‐8, they will receive amiloride 10mg/day. The volunteers will be seen weekly to assess adherence by tablet count. CONDITION: Bipolar affective disorder PRIMARY OUTCOME: Change in urinary concentrating ability, as assessed over 6 hours after administration of 40mcg desmopressin intranasally after overnight fluid deprivation. This will be determined based on plasma and urine osmolality measurements. SECONDARY OUTCOME: Resting EEG ‐ 10 minutes recording Safety and tolerability, as assessed by safety laboratory tests, vital signs and reported adverse events INCLUSION CRITERIA: 1. Capable of understanding and signing an informed consent. 2. Aged >18 years on the day of consent. 3. Good general health. 4. Suitable venous access.