Reckitt Benckiser Group’s Nurofen painkiller costs 2.20 pounds ($2.80) for a pack of 16 pills. UK grocer J Sainsbury sells a private-label alternative for a third of the price. That’s the challenge facing Reckitt’s incoming CEO, Laxman Narasimhan. As consumers increasingly seek out cheaper versions of commoditised consumer goods like ibuprofen, job No. 1 will be to fix the company’s consumer health business.