Psychiatry and Mental Healthmiddle twist
A 45-year-old woman with bipolar I disorder, stable on lithium carbonate 1,000 mg nightly for six years with levels consistently 0.7–0.8 mmol/L, presents with three days of coarse tremor, vomiting, diarrhoea and increasing unsteadiness; today she is confused and slurring her words. Two weeks ago she started taking over-the-counter ibuprofen regularly for back pain, and a week of hot weather has reduced her fluid intake. Her serum lithium is 2.9 mmol/L (therapeutic 0.6–0.8), creatinine 168 µmol/L (previously 74), and an ECG shows sinus bradycardia at 48/min.
Which one of the following is the most appropriate management?