Evidencias Medicas : Adverse Drugs Reactions: The Naranjo algorithmMedicina General y Familiar

04 junio, 2013

Adverse Drugs Reactions: The Naranjo algorithm

7. Is your patient experiencing an unexpected side effect or new symptoms? Ask your patient where they got their prescription filled. (Photo credit: SafeMedicines)

The Naranjo algorithm, Naranjo Scale, or Naranjo Nomogram is a questionnaire designed by Naranjo et al. for determining the likelihood of whether an ADR (adverse drug reaction) is actually due to the drug rather than the result of other factors. Probability is assigned via a score termed definite, probable, possible or doubtful. Values obtained from this algorithm are sometimes used in peer reviews to verify the validity of author's conclusions regarding adverse drug reactions. It is also called the Naranjo Scale or Naranjo Score.

Questionnaire

1. Are there previous conclusive reports on this reaction?

2. Did the adverse events appear after the suspected 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 appear when the drug was readministered?

5. Are there alternative causes that could have caused the reaction?

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

7. Was the drug detected in any body fluid in toxic concentrations?

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

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

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

Scoring

> 9 = definite ADR
5-8 = probable ADR
1-4 = possible ADR
0 = doubtful ADR

References

Naranjo CA, Busto U, Sellers EM et al. (1981). "A method for estimating the probability of adverse drug reactions". Clin. Pharmacol. Ther. 30 (2): 239–45. doi:10.1038/clpt.1981.154. PMID 7249508.