Parodied: Lance drinks entire bottles of Tonic to cure incredibly minor injuries like paper cuts, hangovers, and hangnails.
Zig Zagged: Tonic can bring people back from the brink of death, except it's really just a placebo, but that's because the real stuff is only given to heroes and the watered down stuff is to gather funds.
Enforced: Lance is a videogame character, and the developers want to use resource management rather than give him naturally regenerating health.
Lampshaded: "You know Lance, you'd never have made it this far in your quest without if it wasn't for that swimming pool worth of Tonic you drank."
Invoked: Lance drinks old, quasi mystic brews in the hopes one of them is a Healing Potion.
Exploited: Knowing his enemies also use Tonic, Lance purposely refills an old bottle with poison and reverse pickpockets it into his enemies inventory.
Defied: Lance refuses to drink Tonic because it would make him become sloppy and reckless in his fighting strategies.
Discussed: "Isn't it ironic that this potion grants a new lease on life, yet it promotes a desensitization to violence because it makes its effects easily reversed?"
Conversed: "Wow, this Lance character in the game must singlehandedly keep this entire world's potion brewing industry in the black."
Deconstructed: Lance's use of Tonic has him labeled as a cheater and coward by his enemies, who taunt that You're Nothing Without Your Phlebotinum. Which leads Lance to charge into attack without it and get defeated.
Because Tonic can cure any injury, it is seen by society as dangerous for promoting carelessness and violence, so it becomes a controlled substance. Lance has to constantly fight feelings of inferiority for using it, and may even decide it's Too Awesome to Use.
Alternatively, Lance is a Combat Pragmatist who doesn't give two shits about the personal opinions of his ENEMIES, and he is more than willing to do whatever it takes to pull off a victory. He realizes the edge that Tonic gives him in battle and chooses to take full advantage off it. Sure, it may not be honorable in the eyes of others, but in the end he didn't come here to earn anyone's respect, he came to WIN.
Plotted A Good Waste: The ramifications of Tonic creating a Terminally Dependent Society are explored, and its effects on the player's play style as well (Lance frequently lampshades how he'd be dead, or that he hates the player forcing him to drink yucky Tonic). Halfway through the story, every vial of Tonic becomes so much flavored water as the magic or technology behind it ceases to function. Lance and the world are forced to live a new, fearful existence where their mortality is far more at risk.
Played For Laughs: Tonic can heal you, all right, but it does so by randomly shapeshifting you into a new person/species with a silly outfit.
Played For Drama: Lance is addicted to Tonic, and at the same time it's slowly killing him. And since the only way to cure THAT is to drink more tonic...