I get migraine headaches that are the result of severe muscle spasms in my neck. In total desperation one time I used my prescribed Imitrex injection and injected it directly into the muscle spasm on my neck (all other oral medications had previously made me nausious to the point of vomiting, so I knew no other oral medications would work at that point). Within 10 minutes the muscle spasm in my neck was gone completely, along with the associated excrutiating pain and the subsequent migraine headache.

I have not repeated this process since then (as I have not needed to) and I want to know if this is harmful. (I am aware that the usual injection location is on the thigh, but when I administer the injection in any other place other than directly into the muscle spasm, the medication doesn't work at all.)