I Am Working With A 45 Y.o. Person Post Head

I am working with a 45 y.o. person post head trauma with symptoms of feeling cold since the injury. An article by Jonathan Silver MD (J Neuoropsychiaty Clin Nuerosci 11:2 p248-252, 1999) shows that DDAVP intranasal twice daily for a month can reset the hypothalamus and relieve this troubling symptom
Do you have any further info on this.
In any case, how does a physician obtain the nasal spray medication. How much would it cost for one month's treatment.
Thank you
Richard S. Epstein M.D.