There is nothing wrong with you taking these injections during the day for the purpose of medical treatment, and you do not have to make up those fasts. If you can take them at night without that causing you any hardship, that is better.
And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and upon his family and companions.
Standing Committee for Academic Research and Issuing Fatwas, 10/252.
and see question no: ( 1319 )