No. Marketing is an issue but it's not the main driver.
Everybody else uses price controls to keep prices "reasonable"--the drug companies tolerate this so long as selling to the country exceeds their marginal cost of production. They count on the US market to recoup the $1B R&D costs.
Simply mandate that a drug company can't charge more in the US than they do in any other first world country. Major earthquake in drug costs.
The "discount card" bit is basically a reduction in revenue, it's neither marketing nor administration.