I would imagine it is possible in an "at home setting" as ativan is at least somewhat water soluble. All benzos can be injected, at least the majority of them, in a clinical setting as water solubility doesnt matter as much when you have the resources of say a pharmaceutical producer. There are plenty of ways to get the compound into a solution and into the blood stream through IV that would not be practiced at home due to how unsafe they are just by nature of trying to get a compound into a solution other then water and into the body safely.
I have never done it, have never really looked into it either. IV benzos are often given for amphetamine psychosis and other issues where it is in the patients interest to be sedated or to have their heart rate slow down
