Table 1.

Naranjo's criteria for adverse drug reactions.

Criteria	Yes	No	Don't know	Score
Previous conclusive reports on this reaction	1	0	0
Adverse reaction appeared after the drug was administered	2	−1	0
Adverse reaction improved when drug discontinued or specific antagonist administered	1	0	0
Adverse reaction reappeared when the drug was readministered	2	−1	0
Alternative causes (other than the drug) caused the reaction	0	2	0
Adverse reaction reappeared with placebo	−1	1	0
Toxic drug concentrations measured (systemic or local)	1	0	0
Adverse reaction was dose-dependent	1	0	0
Same adverse reaction to drugs in the same class	1	0	0
Adverse event confirmed by any objective evidence	1	0	0
				9–13 – Definite
				5–8 – Probable
				1–4 – Possible
				0 – Doubtful