Adverse Drug Reactions Flashcards
Discuss the medical importance of adverse drug reactions in terms of morbidity and mortality.
Adverse Drug Reactions (ADRs) are significant causes of morbidity and mortality.
Morbidity: ADRs can lead to acute illness, chronic conditions, functional impairments, and psychological distress. They can also result from drug-drug interactions, which worsen side effects, and affect patients’ quality of life.
Mortality: ADRs are a leading cause of drug-related deaths due to life-threatening reactions (e.g., anaphylaxis, organ failure) and complications from chronic conditions. Older adults, especially those on multiple medications, are at higher risk for fatal ADRs.
Healthcare Burden: ADRs contribute to hospital admissions, increased healthcare costs, and rehospitalizations. Managing ADRs often requires prolonged treatment, monitoring, and specialized care, adding economic strain to healthcare systems.
Prevention and Management: Preventing ADRs involves pharmacogenomic testing, regular monitoring, patient education, and medication reviews. These strategies can reduce risks, improve safety, and optimize outcomes.
In conclusion, ADRs significantly impact patient health and healthcare resources, but many can be prevented with proper management and individualized care.
Discuss factors which may predispose a patient adverse drug reactions and illustrate this with medically relevant examples.
Several factors can predispose a patient to Adverse Drug Reactions (ADRs):
Age: Both children and elderly individuals are at higher risk. Children have immature organs, while the elderly often have reduced organ function, increasing drug toxicity.
Genetics: Genetic variations in drug-metabolizing enzymes can alter drug effectiveness or increase the risk of side effects (e.g., clopidogrel efficacy).
Polypharmacy: Taking multiple medications increases the risk of drug-drug interactions, which can cause ADRs (e.g., warfarin with aspirin increases bleeding risk).
Comorbid Conditions: Diseases like renal failure or liver disease can affect drug metabolism and excretion, increasing toxicity (e.g., NSAIDs in kidney disease).
Sex and Hormonal Factors: Men and women may respond differently to medications due to hormonal differences (e.g., women are more prone to blood clots with oral contraceptives).
Diet and Lifestyle: Certain foods (e.g., grapefruit juice) or alcohol can interact with medications, increasing the risk of ADRs (e.g., grapefruit with statins).
Body Weight: Obese or underweight patients may experience altered drug distribution, leading to potential drug accumulation or insufficient effects (e.g., diazepam in obesity).
Medication Formulation: Drug formulations, such as extended-release vs. immediate-release, can affect drug absorption and safety (e.g., morphine).
Patient Adherence: Non-adherence to prescribed regimens can lead to ineffective treatment or ADRs from improper dosing (e.g., insulin non-adherence in diabetics).
Discuss the definition and classification adverse drug reactions.
Rawlins and Thompson Classification:
Type A (Augmented): Dose-dependent, predictable, and common (e.g., hypotension from antihypertensives).
Type B (Bizarre): Dose-independent, unpredictable, and often caused by immune responses or genetic factors (e.g., anaphylaxis from penicillin).
WHO/CIOMS Classification:
Type 1: Dose-related, pharmacological effects (e.g., sedation from benzodiazepines).
Type 2: Non-dose-related, idiosyncratic (e.g., Stevens-Johnson syndrome from anticonvulsants).
Type 3: Dose- and time-related, occurring after prolonged use (e.g., kidney damage from NSAIDs).
Other Classifications:
Minor vs. Major: Minor reactions are mild (e.g., nausea), while major ones are severe and may require medical treatment (e.g., anaphylaxis).
Serious ADRs: Can lead to death, hospitalization, or permanent damage (e.g., liver failure from acetaminophen overdose).
Understanding ADR classifications helps in identifying, preventing, and managing reactions, improving patient safety and treatment outcomes.
Describe surveillance methods for capturing ADR data.
Spontaneous Reporting: Healthcare professionals and patients voluntarily report ADRs to regulatory bodies, though underreporting can be an issue.
Database Analysis: Large-scale healthcare data is analyzed for ADR patterns, enabling detection of rare or long-term reactions, though causality can be hard to confirm.
Clinical Trials (Phase IV): Post-marketing trials monitor ADRs in larger populations, identifying rare events, but they are costly and resource-intensive.
Case-Control and Cohort Studies: These observational studies compare patients with and without ADRs, helping establish associations but may have confounding factors.
Post-Marketing Surveillance: Ongoing monitoring by regulatory agencies helps detect safety signals through a mix of reporting and studies, though it takes time to identify rare ADRs.
Patient and Public Involvement: Encouraging patients to report ADRs directly can improve data collection, though self-reports may lack accuracy.
Signal Detection Algorithms: Advanced statistical and AI tools process large data sets to detect ADR signals, though false positives and data quality can be issues.
Medical Literature Surveillance: Reviews of published studies and case reports identify ADRs but can suffer from publication bias and incomplete data.
