A patient is brought to the casualty in the state of altered sensorium. He was on lithium treatment for effective fits. On examination, he has tremors, increased TR's and incontinence of urine. He has also undergone an episode of severe gastroenteritis 2 days ago. The serum lithium was found to be 1.95 meq/Lit. The probable cause for his present state is :

Toxic symptoms of lithium toxicity are frequent at serum level of lithium exceeds 1.5 meq/L and regularly seen at plasma concentration above 2 meq/L. The most common symptoms of acute lithium intoxication are neurological, i.e., tremor (being the most common), increased tendon reflexes, seizures, drowsiness, delirium, muscle twitching/weakness and coma. Gastrointestinal toxicity may also occur, e.g. Nausea, vomiting, diarrhea, abdominal pain, and metallic taste. Chronic intoxication can cause hypothyroidism and nephrotoxicity (diabetes insipidus, polyuria, polydipsia, nephrotic syndrome).