What are some common treatments for delirium?

It varies a lot. Frequent redirection and orientation. Ensureing adequate hydration. Reducing overstimulation. Special sense evaluation such as making sure patients have their teeth, hearing aids. Avoiding drugs known to be associated with delirium. Appropriate drug therapy with antipsychotics as first line, especially haloperidol.
Underlying cause. Delirium is general a temporary state of altered behaviour the treatment is the underlying condition- infections, dehydration , pain etc many people with alzheimers will develop a change inbehaviour or even psychotic symptoms from their baseline due to delirium.