The US Food and Drug Administration has approved dexmedetomidine sublingual film for the acute treatment of agitation related to schizophrenia or bipolar I or II disorder in adults. 

This is the first FDA-approved, orally dissolving, self -administered sublingual treatment for agitation. It is recommended to assess vital signs including orthostatic measurements before administering the drug. In mild to moderate cases, 120 mcg SL or buccal initially is recommended. However, if agitation persists, dosage may be increased up to 60 mcg for up to 2 doses at least at a gap of 2 hours; not to exceed 240 mcg/day. In severe cases, the initial dose recommended is 180 mcg SL or BUC. In case the agitation persists, 90 mcg for up to 2 doses at least 2 hours apart may be given: to a maximum daily dose of 360 mcg/day. 

Dexmedetomidine has been continually infused in mechanically ventilated patients before, during, and after extubation. It is not necessary to discontinue dexmedetomidine before extubation. (FDA Okays First Sublingual Med for Agitation in Schizophrenia, BD (medscape.com))