The Pills are an item used in Trilby's Notes. Trilby receives the pills by finding the envelope Agent Lenkmann leaves in the dark hotel's bathroom. Taking the pills will help calm Trilby down, allowing him to return to the normal hotel.
Halfway through the game, the pills lose their effect. When Trilby goes to the basement of the dark hotel, and notices water that rejuvenates the hand of a corpse. Drinking the water causes an effect similar to the pills' effect. Combining the pills with the water restores the calming effect they once had.
At the end of the game, Trilby gives his pills to Sibohann, saying that he knows enough now and will no longer need them.