Table 1. Percent of Medication Classes Used by US Adults Aged ≥ 20 Years in 1999 - 2000 and 2011 - 2012 During the Prior 30 Days.

Drug category	1999 - 2000	2011 - 2012
SRI antidepressants	4.3	8.5
Levothyroxine	4.6	6.0
PPIs	3.9	7.8
Opioid analgesics	3.8	5.7
≥ 5 co-prescribed drugs	8.2	15

Modified from Kantor et al 2015 JAMA. SRI: serotonin reuptake inhibitors; PPI: proton pump inhibitors.