Hello there, I have never had the injection as I have normally been medication compliant and anti-psychotics (oral) have worked for me(I have schizoeffective, not schizophrenia) but the name of the drug could possibly be Halidol or Haliporidal(sorry, don't know if right spelling). And yes, they have been using it for years.

I have had friends on the injections and it really helped them......some side-effects, some people react quite severly, some have a better time of it. I think thorazine and rispiredol is also injectable. If you can get the name of the drug, you can get a bit more info. I was on Olanzapine(oral) which is also injectable. Heres some stuff that I found....hope it helps.....

http://www.mentalhealthcare.org.uk/content/?id=81

http://www.rcpsych.ac.uk/mentalhealt...edication.aspx

Good luck to you and your friend......I hope he starts to feel better soon.