1. Are there previous conclusive reports of this reaction?
2. Did the adverse event appear after the drug was given?
3. Did the adverse reaction, improve when the drug was discontinued or a specific antagonist was given?
4. Did the adverse reaction reappear upon readministering the drug?
5. Were there other possible causes for the reaction?
6. Did the adverse reaction reappear upon administration of placebo?
7. Was the drug detected in the blood or other fluids in toxic concentrations?
8. Was the reaction worsened upon increasing the dose? Or, was the reaction lessened upon decreasing the dose?
9. Did the patient have a similar reaction to the drug or a related agent in the past?
10. Was the adverse event confirmed by any other objective evidence?
To download the Naranjo Adverse Drug Reaction Probability Scale Worksheet