The trick is in the patenting of the drugs. This is the payback the R&D folks get, as their company (or the company they sell to) will get a monopoly for a limited time (I think it's around 20 years for drugs).
The health effect on this is that the drug is prohibitively expensive for the first 20 years, then plummets in price as generics are made. It is good, IMO, when it plummets in price and we should never let the BigDrugCo's sell us on the notion that generics are bad. They are, in effect, the return of the system to the free market that would have existed absent the patent.
Of course, if you're poor, this just means you have to figure you can't afford any new drug you need until it's been around for 20 years. By which time your health has certainly been permanently affected. Therein lies the rub.
And, BigDrugCo tossing a few million at this charity or that charity may make BigDrugCo look and feel better, but it really doesn't address this problem.