With the Affordable Care Act and political scrutiny over prescription drug prices shaking up the health care sector, it’s no mean feat to simultaneously steer a massive health insurance acquisition and a tie-up among retail pharmacies through antitrust review.

That’s what Jones Day’s Phillip Proger faces as antitrust counsel for Aetna Inc. in its proposed $37 billion acquisition of Humana Inc., and for Rite Aid Corp. as its rival, Walgreens Boots Alliance Inc., attempts a $17.2 billion buy.