Thanks for your question.
You probably know bipolar disorder
is a mixture of mania and depression and the treatment of it is mood stabilizer
group of drug and lithium is a mood stabilizer but in severe cases only mood stabilizer alone is not helpful so we use anti psychotic drugs for augmentation so doctor prescribe oleanz or olanzapine
but our always target is to stop the mood stabilizer gradually as the patient get stable and your husband the same thing was done.
But oleanz is a very good sleep promoting agent so as he now stopped it he have sleep problem and dizziness.Nothing to be worried consult with your psychiatrist
he will either start oleanz again in low doses like 2.5-5 mg daily or add some benzodiazepine
for sleep promotion.
Dr Sourav Ganguly