Skip to main content

Table 1 Naranjo adverse drug reaction probability score

From: A serious adverse drug reaction probably induced by clonazepam: a case report of myotoxicity

No. Item Yes No Do not know Score
1 Are there previous conclusive reports of this reaction? + 1 0 0 + 1
2 Did the adverse reaction event appear after the suspected drug was administered? + 2 −1 0 + 2
3 Did the adverse reaction improve when the drug was discontinued or a specific antagonist was administered? + 1 0 0 + 1
4 Did the adverse reaction reappear when the drug was readministered? + 2 −1 0 + 2
5 Are there alternative cause (other than the drug) that could on their own have caused the reaction? −1 + 2 0 −1
6 Did the reaction reappear when a placebo was given? −1 + 1 0 0
7 Was the drug detected in the blood (or other fluids) in concentrations knows to be toxic? + 1 0 0 0
8 Was the reaction more severe when the dose was increased or less severe when the dose was decreased? + 1 0 0 0
9 Did the patient have a similar reaction to the same or similar drugs at any previous exposure? + 1 0 0 0
10 Was the adverse event confimed by any objective evidence? + 1 0 0 + 1
     Total 6
  1. Definite:≥9; Probable: 5–8; Possible: 1–4; Doubtful: ≤0
\