I was just wondering about this.... because today I woke up kind of late and I took my adderall xr 20 mg at 11 am. Then I had a dentist appointment at 130 and I knew I'd be there till like 3. I didn't want to take my second does at 3 because I knew I'd be up all night since it happened before. So I took my second dose about 1:30.

Now here I am 1 in the morning still awake. SO what I"m wondering is, if I take my doses too close together does that make the effects last longer? I normally take one of my doses around 7 am and the next dose around 12 or 1 and I have no problems sleeping.

I also drank a VAULT energy drink (the new energy drink by coca cola) at 330. Would it still be affecting me now?

It kind of sucks because I have a big test in the morning at 8, and have to get up at 6 so I wanted to be rested up for this test! Now if I do bad because I'm too tired or something I'm going to be really mad!!

yeah it does it makes have a stronger feeling.

Well, think about it...You're normally just taking 20mg then as your body processes it, you no longer have that 20mg's in your system and you take another 20mg to keep it constant. When you take both so close together, you're practically taking both doses together making it a 40mg XR instead of a 20mg XR, even though your body had a little time to process it. It probably also depends on if you eat, etc.

I'll tell you what it was...the vault energy drink that you had at 330. I made the same mistake about a month ago!

I started taking a little higher dose, was not hungry at dinner, then at 8ish i was craving starbucks. long story short, i drank 12oz of the new green tea latte and was up until 5 in the morning.

It may have been you taking your doses close together but more than likely it was the energy drink on top of that at such a late time in the day.

Well I did it again I guess....
Took my first pill at 11 in the morning whe I woke up then took my second pill at 230 in the afternoon. Then at 4 I drank a 20 ounce of Mountain Dew to give me some energy at work. Now ever since 8 I've been dragging and I feel sooo tired. I've laid in bed for an hour and still haven't gotten to sleep. Its not like I'm hyper or anything and I want to run around. Its just that I'm laying in bed and can't sleep even though I'm tired.

I've never been caffeine sensitive before... i could drink a bottle of mountain dew and then go right to sleep. So I don't know why this is happening now its really weird.

Was 230 too late in the day to take my second adderall XR 20 mg?? Maybe thats it, I dunno? I'm clueless