Table 4.

Ratings provided by commercial medication knowledge base vendors on the final set of critical DDIs

DDI#	DDI pairs	First DataBank–NDDF Plus	Cerner Multum	Wolters Kluwer (Medi-Span)	Average score
3	Amphetamine and derivatives–MAO inhibitors	7	9	9	8.33
4	Atazanavir–PPIs	7	8	8	7.66
6	Febuxostat–azathioprine/mercaptopurine	7	9	9	8.33
8	SSRIs–MAO inhibitors	8	9	9	8.66
11	Irinotecan–CYP3A4 inhibitors	6	9	7	7.33
12	Linezolid–triptans	6	5	5	5.33
16	Narcotic analgesics–MAO inhibitors	8	9	7	8
20	TCAs–MAO inhibitors	6	9	7	7.33
21	QT prolonging agents–QT prolonging agents	6	9	8	7.66
22	Ramelteon–CYP 1A2 inhibitors	5	9	7	7
23	CYP 3A4 inducers–protease inhibitors	5	9	8	7.33
25	HMG Co-A reductase inhibitors–CYP 3A4 inhibitors	5	9	8	7.33
27	CYP 3A4 inhibitors–ergot alkaloids and derivatives	7	9	8	8
28	Tizanidine–CYP 1A2 inhibitors	8	9	8	8.33
30	Tranylcypromine–procarbazine	7	9	4	6.66
31	Triptans–MAO inhibitors	7	9	7	7.66