Welcome here. If this is a recent event I consider it urgent you contact your doctor, produce the tablets or script and explain the whole matter. Then ask for advice on the medical side concerning reactions to existing meds and also about ceasing the medication (if that is appropriate) as this often needs to be done under medical supervision.
Further ask your doctor's opinion if the matter is indeed unprofessional and what steps should reasonably be taken. Under normal circumstances it is your doctor who refers you to the psychiatrist and then liaises with him or her on an ongoing basis.
OK, with all that said it seems you have a very taxing time. I hope the cancer has been dealt with and I'm sorry over the death of your mother, something that can be very hard to deal with for most of us. I'm also sorry (if I understand correctly) your family situation is a most unhappy one too.
Would you mind clearing up a matter? Was this your wife, or your ex-wife you are talking abut? I 'm not sure of your circumstances..
Nevertheless I beleive you to be right in all your assumptions. While a psychiatrist is able to issue prescriptions this is done with due regard to the physical and mental welfare and circumstances of the client. It includes an assessment or diagnosis, knowledge of the client's current treatment and medication and other factors.
To blindly issue a prescription to someone who is not a client simply on the basis of another's word seems to me to be a complete failure of duty of care. Leaving it to the judgment of a pharmacist who may or may not be familiar with all your usual medications is not sufficient. In addition the client should have been offered sufficient information to make an informed decision on taking the medication and normally the client's doctor informed.
I do beleive the fact it was an anti-psychotic is a side issue, it is the circumstances under which it was given and its possible effects that is of great concern.
It my be possible to issue a complaint, I'd not know. In my state there is a Medical Ombudsman who can be approached about such matters, I'm unsure elswhere.
The most likely professional body, the Royal Australian and New Zealand College of Psychiatrists offers the following procedural advice for complaints against its members:
I'd like you to know you are not alone and we would very much like to know how you get on