I don't know if you could stay up 72 hours on it or not, but it seems reasonable.
I take two 100mg tablets in the morning and it lasts through the day. Taking additional tablets later simply extends the effect. With Ritalin, you do feel when it starts having effect, and you can feel when it is wearing off (the Ritalin works typically 4 hours at a time.) With the Provigil you don't really feel it per se, you just don't feel sleepy. A colleague at work contacted our pharmacy while on speakerphone to ask how it works - it apparently works on dopamine receptor sites blocking reuptake, and on "alpha"(?) (I didn't make out all of the second part, though :-( It has yet to make the PDR, but is documented on the pharmacy formulary info subscriptions. Your local pharmacist could get you more detailed info on the actions, contraindications, possible side effects etc.
The listed potential side effects included euphoria, headaches, irritability, difficulty sleeping (duh!). It is quite expensive though. Without a health plan a months supply was about $250. Unlike Ritalin and the amphetamines it is not Schedule II, so those limitations don't apply (schedule II require you to fill the prescription within 72 hours, must be issued in duplicate, cannot include refills, must reference the diagnosis, must include a street address, can only be a 30 day supply.)
James D. Wilson
"non sunt multiplicanda entia praeter necessitatem" William of Ockham (1285-1347/49)
[mailto:firstname.lastname@example.org]On Behalf Of Brian Atkins Sent: Friday, May 21, 1999 10:19 PM
Subject: Re: New Drug for Narcoleptics
What happens if you take it more often than once in the morning.. is it really possible to stay usefully awake anywhere near 72 hrs?