Is it a HIPAA violation for a pharmacy to change information in my prescription profile without my knowledge or consent?

I'm no Texas attorney, no health care attorney and no HIPAA attorney, but I can't imagine that it violates HIPAA for them to change their own internal records.  You don't mention the nature of the information they changed or the basis for the change. I certainly hope that the change didn't result in any harm to you. If not, just talk with them about it and/or take your business elsewhere. If so, then by all means, talk to a Texas health care attorney as you have problems larger than a HIPAA violation.