What Causes Patch Of Hair Above Forehead?

Hi, I m male 38 yrs ,i have lost a patch of hair above fore head, when consult a skin specialist he gave me wysolone for 30 days, now, 10 days have past but somebody told me about the heavy side effects of this drug, so , i want to know whether shuld i carry for the rest of the doses or leave it for some other medicine ?