Page 37 - Community pharmcy practice E-book 2025
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31/10/2025, 23:40 Community Pharmacy Practice - Course Materials
Classification of ADRs
the DoTS method based on :
the Dose at which they occur relative to the beneficial dose
the Time-course of the reaction,
and individual Susceptibility factors
Other classification of ADRs
Type A (Augmented)
Type B (Bizarre)
Type C (Chemical)
Type D (Delayed)
Type E (Exit/End of treatment)
Type F (familial/failure)
Type G (genotoxic)
Type H (hypersensitivity)
Type U (unclassified)
Type A (Augmented ) reactions
Predictable, common and related to Pharmacological action of the drug
About 80% of all adverse drug reactions are type A and for most prescription this type of
reaction is described in handbooks such as the physician's desk reference
Dose dependent, can be alleviated by a dose reduction
E.g. Bleeding with anticoagulants, bradycardia with beta blockers, headache with nitrates,
postural hypotension with prazosin
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