Psychopharmacology in psychiatric emergencies.

Pharmacotherapy is crucial to the emergency psychiatric treatment of patients who are out of control in a variety of psychiatric and medical disorders. The time required for the more definitive pharmacological treatment of the major psychiatric syndromes is such that they can best be only started in the emergency setting. The emergency treatment of patients who are severely agitated, violent, or psychotic is based on IM administration of antipsychotic medications, such as haloperidol. In conjunction with psychological support this can provide effective, safe, and humane treatment. Sedative-hypnotics, such as diazepam, can be helpful for less severe anxiety states. This article focused on clinical and pharmacokinetic principles of the use of these medications, the understanding of which can help maximize their effective use in emergencies. Topics which are emphasized include sedative, antipsychotic and disinhibiting effects, side effects, absorption after oral and IM administration, and the concepts of steady-state kinetics and the "loading dose."