What is an adverse drug reaction? Classify (with drug examples) the different types.
This question was very poorly answered. Textbooks give different classifications so some largesse was allowed, but both immunologic and physicochemical (kinetic and dynamic) were expected. Marks were allocated for both type and an example - some candidates failed to provide examples or listed a drug side effect without explanation. Some candidates were ‘creative’ with classification systems but where appropriate examples were given marks were awarded. No marks were gained for detailed descriptions of LD50 and therapeutic ratios.
It is pleasing to see the examiners being generous with their marking ina question about a definition which nobody can agree upon. Truly, each author on this topic gives a different definition. Here's a couple by the WHO:
- An adverse drug event is “any untoward medical occurrence that may present during treatment with a pharmaceutical product but which does not necessarily have a causal relationship with this treatment” (WHO definition, 2005)
- An adverse drug reaction is “a response to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis, diagnosis, or therapy of disease or for the modification of physiologic function.” (WHO definition, 2005)
A common classification system which is not "creative" is the alphabetic A-B-C-D-E-F system originally proposed by Edwards et al (2000).
|A: Dose-related reactions||
|B: Non-dose-related reactions||
|C: Dose and time-related reactions||
|D: Time related reactions||
|E: Withdrawal reactions||
|F: Unexpected failure of therapy||
Edwards, I. Ralph, and Jeffrey K. Aronson. "Adverse drug reactions: definitions, diagnosis, and management." The Lancet 356.9237 (2000): 1255-1259.
Schatz, S., and R. Weber. "Adverse drug reactions." Pharmacy Practice 1 (2015): 1.
Kaufman, Gerri. "Adverse drug reactions: classification, susceptibility and reporting." Nursing Standard (2014+) 30.50 (2016): 53.
Rawlins MD, Thompson JW. "Pathogenesis of adverse drug reactions." In; Davies DM, ed. Textbook of adverse drug reactions. Oxford: Oxford University Press, 1977: 10
Rawlins, Michael D. "Clinical pharmacology. Adverse reactions to drugs." British medical journal (Clinical research ed.)282.6268 (1981): 974.
Vervloet, Daniel, and Stephen Durham. "Adverse reactions to drugs." BMJ 316.7143 (1998): 1511-1514.