My 34 year old daughter is diagnosed with schizophrenia .
Thanks for using Healthcaremagic.
I read your query and understand your concerns.
Haldol (Haloperidol decanoate) is not known to cause low backache which increases with time. It is possible that backache is result of muscle spasm due to haldol (which is rare) but there are no known mechanisms which can worsen it in future.
There is good possibility that Haldol have no direct connection with recent onset low backache and there is need for more evaluation in respect to low backache provided it persists longer. Since there is no direct connection it is unlikely to progress with further Haldol shots.
I hope this helps you.
Feel free to write back to me if you have more questions.
Thanks and regards.