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Table 1 Adverse drug reaction probability scale by Naranjo

From: Assessing causality by means of the Naranjo scale in a paediatric patient with life threatening respiratory failure after alemtuzumab administration: a case report

 

Yes

No

Unknown

1. Are there previous conclusive reports on this reaction?

+ 1

0

0

2. Did the adverse event appear after the suspected drug was administered?

+ 2

−1

0

3. Did the adverse event improve when the drug was discontinued or a specific antagonist was administered?

+ 1

0

0

4. Did the adverse reaction reappear when the drug was readministered?

+ 2

−1

0

5. Are there alternative causes (other than the drug) that could on their own have caused the reaction?

−1

+ 2

0

6. Did the reaction reappear when a placebo was given?

−1

+ 1

0

7. Was the drug detected in the blood (or other fluids) in concentrations known to be toxic?

+ 1

0

0

8. Was the reaction more severe when the dose was increased, or less severe when the dose was decreased?

+ 1

0

0

9. Did the patient have a similar reaction to the same or similar drugs in any previous exposure?

+ 1

0

0

10. Was the adverse event confirmed by any objective evidence?

+ 1

0

0