comes in dosages of 12mg/ml and can be give a daily dosage of maximum 12mg/day. I think if you are becoming resistant to triptans generally switching to injectable forms might also lead to resistance. What you should do is meet your doctor so he can prescribe another anti-migraine
such as ergotamine
. That can be taken for a while before you can start taking triptans once more as they have known to have few side effects as compared to use of ergotamine.
Hope this helps