Psychiatryniche
A 29-year-old woman is admitted with a first manic episode. She has not slept for four nights, has telephoned strangers at 3 am and has spent her rent money on a car she cannot drive. Lithium carbonate is started and given as a single dose each night. On day six, a serum concentration taken twelve hours after the dose is 0.65 mmol/L; she remains overactive and intrusive on the ward. Her kidney and thyroid function are normal and she has no adverse effects. Which one of the following twelve-hour serum lithium concentrations should be targeted for this episode?