Life-threatening hyponatraemia and intramuscular olanzapine: the world's longest therapeutic trial.

This case report provides a different perspective on the management of a patient with a psychotic illness. The detained patient, a man aged 50, had specific delusional beliefs about toxins affecting his kidneys, such that he needed to drink water to 'detoxify' himself. This resulted in him developing life-threatening hyponatraemia. It became clear that he was very resistant to taking oral medication and was reluctant to engage with any psychological treatment. A novel approach was considered, involving the 'off licence' use of short acting intramuscular olanzapine for the successful treatment of the psychotic illness. The case demonstrates the safe use of intramuscular olanzapine for 155 days, which is the longest reported case for the use of intramuscular olanzapine for the treatment of a psychotic illness. The individual was later discharged on oral olanzapine.