When the government imposes restrictions that artificially raise prices above the competitive market level, economic theory predicts that producers will engage in anti-social rent-seeking behavior to maximize their rents. Drug patents, which raise drug prices by several hundred percent above the competitive market price (sometimes several thousand percent), lead to all sorts of corruption, just as economic theory predicts.
Unfortunately, economists show relatively little interest in this interference with the free market. Fortunately, the NYT shows more interest. It has a good article on doctor run foundations that receive large payments from drug and medical supply companies. These foundations tend to produce research that shows the effectiveness of their donors' products.