Reddit reviews Jet-Alert Double Strength, 90 caplets

For future reference you only would need half of one of these and they're like 6c a pill.
https://www.amazon.com/dp/B001QVCSZC/ref=cm_sw_r_cp_api_4deRyb5T7WGAS

As far as staying awake in lecture your only option is to just take notes as hard as you can. try to write down every word your professor says.

I cut out energy drink using these -- same active ingredient but without all the crap.

Also, as I said in another response, mineral water makes a great chaser for quality booze. Also, if you blow out across your tongue after taking a shot it evaporates the alcohol and reduces the urge to wash it down with something.

If you haven't slept enough but need to drive, keep some caffeine pills in your car. You can also pull over and get coffee. I'd prefer to skip spending extra for crappy coffee to just get caffeine. Each pill is about 1.5 cups of coffee. If it's a shorter drive, take half. Doesn't make me jittery or anything but I also drink a fair amount of coffee.