The present invention provides a method for treating multiple sclerosis (MS), and for reducing flu-like symptoms associated with administration of an interferon to a patient with MS. The method involves intramuscularly administering the interferon to the MS patient according to an escalating dosing regimen in weeks 1 to 3, and a full therapeutically effective dose of interferon in week 4. In one embodiment of the invention, the escalating dosing regimen comprises administering one quarter of the therapeutically effective dose in week 1, half of the therapeutically effective dose in week 2, and three-quarters of the therapeutically effective dose in week 3. Also provided are titration packages for enabling compliance with a regimen of changing dosage of an interferon over a period of time.