The guidance published by the Royal College of Psychiatrists in the document
'Management of Imminet Violence - Clinical practice guidelines to support
mental health services'- March 1998 suggests the following:

1. Consider carefully the design of the care environment in which
potentially violent individuals are managed in.
2. Consider training staff in methods of de-escalating and coping with
violent behaviour.
3.Either an anti-psychotic alone or a benzodiazepine alone should be used if
medication is to be used; the oral or IV routes are preferred as absorption
from IM route is erratic.
"Lorazepam 2-4mg Po, slow IV or IM is very safe and effective" Quote from
RCPsych. (1997) - The Association between Antipsychotic Drugs and Sudden
Death.
4. That there are risk factors predictive of violent behaviour on which
staff could take preventative action:- personal history, clinical variables
and situational factors.

I use Lorazepam PO or IV generally for chemical restraint. (See also The Maudsley guidelines)

Tony Adams
Peterborough