Here's a nice review and it's free full text.
Nonpharmacologic modalities are preferred by far over drugs though the latter are popular and sometimes necessary when the delirium is agitated. Data to support the use of drugs are sparse. Antipsychotics tend to be preferred over benzos except for alcohol withdrawal delirium, in which benzo therapy is the treatment of choice and antipsychotics are avoided. There is little to recommend second generation over older (e.g. haldol) agents. Dexmedetomidine has promise and is popular, but evidence in favor of its use is weak.