Water is not an issue, although grapefruit juice would be on the list of drinks to avoid. The issue with eating and Tasigna is not so much about direct food/drug interactions. It is a response from Novartis (lawyers?) to the heart QT elongation issue since there is a possibility that some foods can cause the drug to stay in the bloodstream longer, as grapefruit apparently can. So theoretically, a 300mg dose could act more like roughly 350mg (just guessing on the increase -- no one knows for sure) when consumed with some foods. But in a study of 846 patients taking Tasigna the QT interval issue was monitored. The study concludes that:
"No patients in the study had prolongation of QT interval >500 milliseconds. No sudden deaths occurred in any of the treatment arms"
Novartis says: "You may lower your chances for having QT prolongation with TASIGNA if you take TASIGNA on an empty stomach."
The heart QT cycle issue most directly relates to those who had an elongated heart QT cycle before starting Tasigna. If a person has a normal QT cycle while taking Tasigna, one could ask whether the 2 hour eating restriction was really necessary. I am no one to question the Novartis statement, but if it were me, and my QT was normal while taking Tasigna, I doubt I personally would be so worried about the 2 hour warning. But get permission from your doc if you want to ignore the eating restriction. Note that this Novartis statement is fairly wimpy and does not sound like a dire warning, just an "oh by the way" kind of statement. But they put it in their dosing instructions for everyone to account for a 2% issue. Not trying to tell people what to do, just trying to put the 2 hour eating restriction issue into perspective.
Here is the complete Novartis info sheet for Tasigna: