When I worked as a registered nurse, when giving parenteral benzodiazpine preparations, they all had to be given IV as Diazepam for instance, the 2nd most common of the 2 benzos we used to administer in this manner, was unsuitable for IM injection as even dissolved it was a less effective ROA than oral due to it's erratic and unpredictable absorption from the muscle into the bloodstream. As I worked with patients who suffered from severe and enduring psychotic illnesses we often would have to enforce treatment on them using the legislation covering the care of such patients at the time. Unfortunately, most of these cases would involve the use of neuroleptics and benzodiazepines in order to rapidly sedate patients who were behaving in a dangerous manner to themselves and others.
The treatment in such instances would usually involve administering an extremely powerful version of the neuroleptic zuclopenthixol known as Clopixol Acuphase which would heavily sedate the patient for 18 - 30 hours while reducing the positive symptoms of their psychosis. However, the Acuphase would take up to 120 minutes to start working, so we would co - administer 2mg of Lorazepam for quick sedation while waiting for the antipsychotic to work.
Sadly, in a lot of these cases we had to restrain the patients (which would involve a team of 5 other nurses as we are not allowed to use mechanical restraints in acute mental health settings in the UK such as straitjackets and the like) so even once we had the patient safe and immobile, we could not prevent them from struggling or hold them completely still. This meant that the only option for parenteral administration of the above mentioned medicines would be to give them IM in one of the large muscles in their bum or on their upper legs, as due to the patients movement any attempt at safely administering a drug IV was impossible.
However, the lorazepam, as well as having a good effect profile for this purpose was also the only benzodiazepine that we could give IM as it did not have the absorption problems that other injectable benzodiazepines had. Even so, when preparing the drug we had to dilute it with the same amount of water before admin (all of our injectable lorazepam came in the form of 2mg per 2ml 'Ativan' ampoules for injection so if the full dose was to be given 2mls of water would have to be added beforehand)
So, even the pharm grade injectable preparations of the benzodiazepines we used were not, by advice of general academia and the National Institute for Clinical Excellence (NICE), very efficient to use in most cases and it was always best practise to administer oral benzo preps wherever possible.
So, as most benzos are usually only injected in the case of emergencies within medical practise, patients who take them regularly always used tablets or elixirs so no body was ever given them by injection on a regular basis. So, while I cannot answer your question Keif, the discouragement of regular injections of these drugs does suggest that they probably don't do any favours to the quality of you wiring in one way or another.
thanks for all the help though it is greatly appreciated!
