Naranjo algorithm
The Naranjo algorithm is a questionnaire designed by Naranjo et al[1] for determining the likelihood of whether an ADR (drug-related side effects and adverse reactions) is actually due to the medication rather than the result of other factors. Probability is assigned via a score termed definite, probable, possible or doubtful.
An alternative, simpler scale has been proposed by the World Health Organization (WHO).[2][3]
Questionnaire
1. Are there previous conclusive reports on this reaction?
Yes (+1) No (0) Do not know or not done (0)
2. Did the adverse event appear after the suspected drug was given?
Yes (+2) No (-1) Do not know or not done (0)
3. Did the adverse reaction improve when the drug was discontinued or a specific antagonist was given?
Yes (+1) No (0) Do not know or not done (0)
4. Did the adverse reaction appear when the drug was readministered?
Yes (+2) No (-1) Do not know or not done (0)
5. Are there alternative causes that could have caused the reaction?
Yes (-1) No (+2) Do not know or not done (0)
6. Did the reaction reappear when a placebo was given?
Yes (-1) No (+1) Do not know or not done (0)
7. Was the drug detected in any body fluid in toxic concentrations?
Yes (+1) No (0) Do not know or not done (0)
8. Was the reaction more severe when the dose was increased, or less severe when the dose was decreased?
Yes (+1) No (0) Do not know or not done (0)
9. Did the patient have a similar reaction to the same or similar drugs in any previous exposure?
Yes (+1) No (0) Do not know or not done (0)
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 drug-related side effects and adverse reactionss". Clin. Pharmacol. Ther. 30 (2): 239-45. PMID 7249508. [e]
- ↑ Edwards IR, Aronson JK (2000). "Drug-related side effects and adverse reactionss: definitions, diagnosis, and management". Lancet 356 (9237): 1255–9. DOI:10.1016/S0140-6736(00)02799-9. PMID 11072960. Research Blogging.
- ↑ Nebeker JR, Barach P, Samore MH (2004). "Clarifying adverse drug events: a clinician's guide to terminology, documentation, and reporting". Ann. Intern. Med. 140 (10): 795–801. PMID 15148066. [e] (See table 2)