Yes, it is appropriate to address someone with a PhD as "Doctor."
Anybody who is a doctor.
The proper way to address a Doctor of Osteopathic Medicine (DO) (not Doctor of Osteopathy) is Doctor (Dr.) since they are medical physicians.
if they have a doctorate then that's how to address them
Address on envelope to a doctor: Dr. John Doe is the general form.
I am pretty sure you just address it normally until the person is actually a doctor
i need to address a doctor this second
Yes, it is appropriate to address someone with a doctorate as "doctor" as a sign of respect for their academic achievement.
"Doctor"
The web address of the Arkansas Country Doctor Museum is: http://www.drmuseum.net
He does not really have an address: He is nomadic.
The way to write a letter to a doctor asking for help is to address it professionally to the doctor. Next, be specific about the reason help is needed and explain in details. Add contact information including phone numbers, address, and an email address so that the doctor can answer the help request.