Hi...I Am Being Treated For ADHD With Aderall IR 30mg

Hi...I am being treated for ADHD with Aderall IR 30mg 2-3 times per day for approximately a year 1/2 now and my dr is changing the dosage to 40mg twice a day....I took my precription in to be filled but they don't carry 40mg IR tabs....Do they exist?? I couldn't get a straight answer from this pharmacy. ( not the usual place I go to). My doctor is away till Monday and I really need to know.