Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net sales	$ 2,493	$ 2,379
Cost of products sold	730	672
Gross profit	1,763	1,707
Operating expenses:
Selling, general and administrative expenses	869	860
Research and development expenses	280	261
Royalty expense	16	18
Amortization expense	160	141
Intangible asset impairment charges	67	1
Contingent consideration expense (benefit)	(28)	5
Restructuring charges (credits)	6	13
Litigation-related net charges (credits)	(148)	0
Operating expenses	1,222	1,300
Operating income (loss)	541	407
Other income (expense):
Interest expense	(109)	(61)
Other, net	25	(23)
Income (loss) before income taxes	457	323
Income tax expense (benefit)	33	26
Net income (loss)	$ 424	$ 298
Net income (loss) per common share — basic	$ 0.31	$ 0.22
Net income (loss) per common share — assuming dilution	$ 0.30	$ 0.21
Weighted-average shares outstanding
Basic	1,387.7	1,376.5
Assuming dilution	1,408.4	1,396.8