Treat the underlying pathology.
If<unk>  distressing, can trial dose of PO antipsychotic
In the case of alcohol withdrawal hallucinosis, no standard therapy has been established, although treatment with neuroleptics (e.g. Haldol) has shown some benefit.  Also continue to treat the alcohol withdrawal.
Hallucinations
Serotonin-Like Agents
Extrapyramidal reaction
Lysergic acid diethylamide 
Ergotism
Psilocybin 
Dysphonia
N,N-Dimethyltryptamine 