Pfizer is the first big pharmaceutical company to reach an agreement with the Trump administration over most-favored nation drug pricing, a deal that lowers U.S. prices of certain medications and makes them available directly to patients through new online channels. The agreement announced Tuesday also gives Pfizer a grace period before facing potential tariffs on its drugs. With most-favored nation pricing, the prices of a drug in the U.S. will be matched to the lowest price of the same drug in a comparable developed nation.