According to the Rawlins and Thompson classification, which type of adverse drug reaction is dose-dependent, predictable, and occurs in normal individuals at higher than recommended doses?

Explanation

## Rawlins and Thompson Classification of Adverse Drug Reactions The Rawlins and Thompson system divides ADRs into two main categories based on their relationship to drug dose and predictability. ### Type A Reactions (Augmented) **Key Point:** Type A reactions are dose-dependent, predictable, and occur in normal individuals when drug doses exceed the recommended range. - Represent 80% of all ADRs - Caused by exaggeration of the drug's known pharmacological action - Examples: hypoglycemia with insulin overdose, bleeding with warfarin overdose, hypotension with antihypertensives - Reversible upon dose reduction or drug withdrawal - Low mortality rate ### Type B Reactions (Bizarre) - Dose-independent and unpredictable - Occur in susceptible individuals even at therapeutic doses - Not related to the drug's primary pharmacological action - Examples: anaphylaxis, Stevens-Johnson syndrome, drug-induced lupus - Often immune-mediated or genetically determined - Higher mortality rate ### Type C Reactions (Chronic) - Dose and time-dependent - Occur after prolonged drug exposure - Examples: pulmonary fibrosis with bleomycin, osteoporosis with corticosteroids ### Type D Reactions (Delayed) - Occur after a long latent period following drug exposure - Examples: carcinogenesis, teratogenesis **High-Yield:** Type A reactions are the most common (80%) and most important to recognize clinically because they are preventable by dose adjustment. **Mnemonic:** **ABCD of ADRs** - **A**ugmented = dose-dependent, predictable - **B**izarre = dose-independent, unpredictable - **C**hronic = time and dose-dependent - **D**elayed = long latent period ### Comparison Table | Feature | Type A | Type B | Type C | Type D | |---------|--------|--------|--------|--------| | Dose-dependent | Yes | No | Yes | No | | Predictable | Yes | No | Yes | No | | Reversible | Yes | Variable | No | No | | Frequency | 80% | 15% | Rare | Rare | | Mechanism | Exaggerated pharmacology | Immune/genetic | Cumulative toxicity | Genetic/carcinogenic | | Example | Warfarin bleeding | Anaphylaxis | Corticosteroid osteoporosis | Drug-induced cancer | [cite:KD Tripathi 8e Ch 6]