PV Toolkit
The three calculations that come up constantly in real case work — Naranjo, WHO-UMC, and PRR/ROR — done in your browser. Nothing you enter here leaves your device.
The Naranjo Adverse Drug Reaction Probability Scale — ten questions, each scored, summed into a probability category. Answer what you can; unanswered questions score as "don't know."
1. Are there previous conclusive reports on this reaction?
2. Did the adverse event appear after the suspected drug was given?
3. Did the adverse reaction improve when the drug was discontinued, or a specific antagonist given?
4. Did the adverse reaction reappear when the drug was readministered?
5. Are there alternative causes that could have caused the reaction on their own?
6. Did the reaction reappear when a placebo was given?
7. Was the drug detected in the blood in a concentration known to be toxic?
8. Was the reaction more severe when the dose was increased, or less severe when decreased?
9. Did the patient have a similar reaction to the same or a similar drug in a previous exposure?
10. Was the adverse event confirmed by objective evidence?
0/10 answered
Doubtful
0 / 13
Training and reference use — always defer to your organization's SOPs and the applicable regulatory framework for real case decisions.
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