Hi (I wasnt sure where the Add info was I'm new)   I am not a doc but I have been on Adderall for 4 years and there is no way I could take it once a day. I thought at 30 mgs in the begining of your post your were referring to the XR. From my experience the drug is still as potent but your body is getting used to it. If i go a week with out taking it then the next 2 weeks I have to go through the side effects all over again for about 5 days or so. I have to take my 20 mgs 3 times a day to make it through. My doc didnt start me out that way though. I started at 10 2x and then 20 2x and now it has been 20 3x for about 4 years and I drink the energy drinks as well but for the extra boost because I am so used to my meds. My Doc told me the FDA says I am on the highest dosage that she can prescribe but I know people who see a Psychiatrist that are one more. Your doc may already have plans to raise your meds to more than once a day if need be. Call him/her and I would just tell the nurse that you feel you need to have another dose in the afternoon. She can relay the message to the doc (they are probably expecting it if they are familiar with it) and maybe you can save a trip/co-pay and they will add another dose with out an office visit. Call tomorrow!