Adverse Drug Reactions and Pharmacovigilance

First module of the course. It defines what counts as an adverse drug reaction, sets out the Rawlins-Thompson A to F and DoTS classifications, and shows how causality is judged using the WHO-UMC categories and the Naranjo score. It separates severity from seriousness, covers predictable type A reactions with worked UK examples, and explains the Yellow Card scheme, black-triangle drugs, the boundary between ADRs and medication errors, and the professional duties of candour and complaint handling.

1. What Counts as an Adverse Drug Reaction: Definitions, Type A to F and DoTS ClassificationPreview

   An adverse drug reaction is not the same as an adverse event or a medication error, and the difference affects how each is documented and reported. This lesson sets out the WHO and MHRA definitions, then works through the Rawlins-Thompson type A to F scheme and the DoTS framework of dose, time course and susceptibility. Amlodipine-induced peripheral oedema is used to show how predictable, dose-related type A reactions behave, and why they matter most in day-to-day prescribing and monitoring.

   10 min
2. Assessing Causality: WHO-UMC Categories, the Naranjo Score, Dechallenge and Rechallenge

   A structured approach to deciding whether a medicine caused a suspected reaction. The lesson works through the core questions that underpin any causality assessment: was the timing plausible, did the reaction improve on withdrawal (dechallenge), did it return on re-exposure (rechallenge), and are there alternative explanations such as infection, disease progression or an interacting drug. It introduces the WHO-UMC causality categories and the Naranjo score, explains why the two tools can disagree, and shows when clinical judgement must override a numerical score. Worked examples draw on amlodipine oedema, statin myopathy after a dose increase and insulin hypoglycaemia in UK practice.

   10 min
3. Severity, Seriousness, the Yellow Card Scheme and Reporting a Medicines Error

   Severity and regulatory seriousness are not the same thing, and confusing them leads to weak reporting. This lesson sets out the criteria that make a suspected reaction serious, explains how the MHRA Yellow Card scheme works in UK practice, including who may report and what the black triangle means, and then separates reporting an adverse drug reaction from reporting a medication error, which follows a different route. It closes with the duty of candour and practical guidance on answering a relative when a medicines process has failed, including what to acknowledge, what not to speculate about, and how to keep the response honest and specific.

   10 min
4. OSCE station: Disclosure of a medication error: double insulin dose to a 70-year-old inpatient
   11 min
5. OSCE station: De-escalating an angry relative: delayed discharge
   11 min
6. ADR case: Peripheral oedema after six weeks of amlodipine
   15 min
7. ADR case: Statin-induced myopathy after a dose increase in a 66-year-old woman
   15 min
8. ADR case: Recurrent nocturnal hypoglycaemia after basal insulin increase and exercise programme
   15 min
9. Quiz: Recognition, Causality and Reporting
   8 min

Covers the immunological and non-immunological mechanisms of drug hypersensitivity, the named syndromes that present at the bedside, and the practical skills of recognising anaphylaxis, giving intramuscular adrenaline, and assessing, documenting or removing a penicillin allergy label. Written for final-year medical and pharmacy students and foundation doctors working in UK practice with British National Formulary dosing and NICE-style guidance.

1. Gell and Coombs Types Applied to Drugs, and the Immediate Reaction: Recognising Anaphylaxis and Giving Intramuscular Adrenaline

   Adverse drug reactions can be grouped by immune mechanism using the Gell and Coombs classification, and that grouping predicts timing, clinical pattern and what to do first. This lesson works through types I to IV with drug examples and expected onset, then focuses on the immediate generalised reaction. It covers how to distinguish anaphylaxis from vasovagal collapse and from panic, how to position the patient, and how intramuscular adrenaline is given as a teaching example, including the reasoning behind the dose and route. It explains why antihistamines, corticosteroids and intravenous fluids have only a limited place in the acute phase. It closes with mast cell tryptase sampling, the observation period and referral. Doses quoted are teaching examples; always check the current BNF and local protocols, which vary by region and formulary.

   10 min
2. Reactions That Are Not Classic Allergy: ACE Inhibitor Angioedema, Aspirin-Exacerbated Respiratory Disease, Amoxicillin Rash in Glandular Fever, and Drug Phototoxicity

   Four drug reactions mimic allergy but arise through different mechanisms, so they need different management and different documentation. This lesson covers bradykinin-mediated angioedema with ACE inhibitors, where antihistamines and intramuscular adrenaline may be ineffective; aspirin-exacerbated respiratory disease, a non-immunological reaction seen in asthma with nasal polyps; the transient maculopapular rash caused by amoxicillin in glandular fever; and tetracycline phototoxicity. It focuses on mechanism, bedside recognition, safe prescribing and how to record these events without creating a false allergy label that restricts future treatment. Written for final-year medical students, pharmacy students and foundation doctors working to UK practice; doses quoted are teaching examples and local formularies and protocols always take precedence.

   10 min
3. Severe Cutaneous Adverse Reactions and Penicillin Allergy: Recognition, HLA Risk, Cross-Reactivity, Documentation and De-labelling

   This lesson covers two high-stakes areas of drug hypersensitivity. First, severe cutaneous adverse reactions: how to recognise Stevens-Johnson syndrome and toxic epidermal necrolysis, the culprit drugs such as aromatic anticonvulsants, sulfonamides and allopurinol, the role of HLA-B*15:02 and lamotrigine titration, and the immediate priorities of stopping the drug and providing supportive care. Second, penicillin allergy: taking a structured allergy history, when skin testing and oral challenge are appropriate, cephalosporin cross-reactivity, accurate documentation, and de-labelling. Written for final-year medical students preparing for finals and the Prescribing Safety Assessment, final-year pharmacy students and foundation doctors working in UK practice.

   10 min
4. Prescribing: Anaphylaxis to Intravenous Co-amoxiclav
   15 min
5. OSCE station: Inpatient Prescribing in a Patient with Penicillin Allergy
   11 min
6. ADR case: Acute anaphylaxis after a new antibiotic infusion
   15 min
7. ADR case: Lip and tongue swelling in a 60-year-old man
   15 min
8. ADR case: A 32-year-old woman with a rash and mucosal erosions
   15 min
9. ADR case: Maculopapular Rash in a 19-Year-Old on Antibiotics for Sore Throat
   15 min
10. ADR case: Acute wheeze after aspirin in a woman with asthma and nasal polyps
    15 min
11. ADR case: Painful sunburn-like rash after beach holiday in a young woman on acne treatment
    15 min
12. Quiz: Drug Allergy and Hypersensitivity: Mechanisms, Clinical Syndromes and De-labelling
    9 min

How commonly prescribed drugs injure the kidney and disturb electrolytes and metabolism, and how that harm is prevented. Covers NSAID and triple whammy acute kidney injury in dehydration, contrast-associated injury and which drugs to hold around contrast, SSRI and thiazide hyponatraemia in older people, metformin-associated lactic acidosis, and prolonged sulfonylurea hypoglycaemia as renal function falls, ending with practical sick-day prescribing guidance for UK practice.

1. Drug-induced acute kidney injury: haemodynamic mechanisms, NSAIDs, the triple whammy and contrast-associated injury

   This lesson explains how medicines cause acute kidney injury through two overlapping mechanisms: reduced renal perfusion and direct tubular or interstitial damage. It focuses on NSAIDs and the loss of prostaglandin-dependent autoregulation, then shows why an NSAID added to a renin-angiotensin system blocker and a diuretic is particularly hazardous during a dehydrating illness such as gastroenteritis. The lesson also covers risk assessment before iodinated contrast, which medicines are commonly withheld before and after contrast, when they are restarted, and where UK practice, local protocols and the supporting evidence vary. Teaching examples use British National Formulary style dosing, but deciding whether a prescription is safe is a matter for local protocols and clinical judgment, not for this lesson.

   10 min
2. Drug-induced hyponatraemia, lactic acidosis and hypoglycaemia: electrolyte and metabolic harm in older people

   This lesson covers the mechanisms, presentation and monitoring of hyponatraemia caused by SSRIs and thiazides in older people, metformin-associated lactic acidosis, and prolonged sulfonylurea hypoglycaemia when renal function falls. It focuses on the renal function and electrolyte results that should prompt dose review, avoidance or stopping, using BNF dosing and NICE-style guidance. Written for final-year medical students preparing for finals and the Prescribing Safety Assessment (PSA), final-year pharmacy students and foundation doctors. Doses and cases are teaching examples only; the platform's deterministic rules decide whether a prescription is safe.

   10 min
3. Sick-day guidance: deciding which medicines to pause during a dehydrating illness

   This lesson shows how to construct, explain and review sick-day guidance for patients at risk of drug-induced harm during a dehydrating illness such as gastroenteritis or a febrile illness with poor oral intake. It covers which drug classes to pause, including ACE inhibitors, angiotensin receptor blockers, diuretics, NSAIDs, metformin, SGLT2 inhibitors, sulfonylureas and lithium, and why each is paused. It covers how long to pause them, when the patient or carer should seek urgent help, and which medicines must never be stopped. It also covers documenting the plan in the record, communicating it in plain language, and reviewing it after recovery, with attention to the limits of the evidence and variation between local formularies and protocols.

   10 min
4. ADR case: Acute kidney injury in a 78-year-old woman with recent gastroenteritis and new NSAID use
   15 min
5. ADR case: Acute kidney injury in a diabetic man after contrast CT
   15 min
6. ADR case: Confusion and Severe Hyponatraemia in an 82-Year-Old Woman on Multiple Medications
   15 min
7. ADR case: Severe Lactic Acidosis and Acute Kidney Injury in a 74-Year-Old Woman
   15 min
8. ADR case: Prolonged hypoglycaemia in an 84-year-old man with chronic kidney disease
   15 min
9. Quiz: Drug-induced kidney, electrolyte and metabolic harm: prevention in everyday prescribing
   9 min

This module covers acute dystonia, akathisia and other extrapyramidal reactions to dopamine antagonists and their treatment, including procyclidine. It teaches recognition and differentiation of neuroleptic malignant syndrome from serotonin syndrome and malignant hyperthermia, then clozapine-induced neutropenia and agranulocytosis with the UK mandatory blood monitoring scheme and other drug-induced neutropenias such as carbimazole and co-trimoxazole.

1. Acute dystonia, akathisia and other extrapyramidal reactions to dopamine antagonists: recognition and treatment with procyclidine

   Extrapyramidal reactions are among the most common and most reversible harms caused by antipsychotics, antiemetics such as metoclopramide and prochlorperazine, and other dopamine antagonists. This lesson covers how to recognise acute dystonia, oculogyric crisis, akathisia and drug-induced parkinsonism, and how their timing and risk factors differ. It then works through immediate management, including procyclidine by mouth, intramuscular or intravenous injection, alternatives such as benztropine, trihexyphenidyl and diphenhydramine, when to reduce the dose or switch drug, and when the offending drug must be stopped. Regional and formulary differences in anticholinergic availability are flagged. Doses quoted are teaching examples only; always check the current British National Formulary and local protocols.

   10 min
2. Neuroleptic malignant syndrome: distinguishing it from serotonin syndrome and malignant hyperthermia

   Three drug-induced hyperthermic syndromes share fever, rigidity and autonomic instability, so they are easily confused at the bedside. This lesson sets out the trigger drugs, typical onset and clinical signature of each: neuroleptic malignant syndrome after dopamine antagonists, serotonin syndrome after serotonergic drugs, and malignant hyperthermia after volatile anaesthetics or suxamethonium. It focuses on the signs that separate them, especially lead-pipe rigidity with bradyreflexia in neuroleptic malignant syndrome against clonus and hyperreflexia in serotonin syndrome. Immediate actions are covered: stopping the trigger, active cooling, benzodiazepines, and the roles of dantrolene, bromocriptine and cyproheptadine, with escalation to critical care and monitoring for rhabdomyolysis and renal failure. Doses quoted are teaching examples only and must be checked against current national guidance and local protocols.

   10 min
3. Clozapine-induced neutropenia and agranulocytosis: mandatory monitoring, red flags and other drug-induced neutropenias

   This lesson covers the blood dyscrasias that make clozapine a high-risk drug, and the monitoring system that exists to catch them early. It explains how the UK clozapine blood monitoring scheme works in practice, how neutropenia and agranulocytosis are defined and recognised, and why sore throat, fever and mouth ulcers are red flags that demand an urgent full blood count. It then sets out when to stop clozapine, carbimazole, co-trimoxazole and other causative drugs, when to seek urgent specialist review, and the role of granulocyte colony-stimulating factor and antibiotics in managing established agranulocytosis.

   10 min
4. ADR case: Acute dystonia in a 22-year-old man after haloperidol
   15 min
5. ADR case: Fever, rigidity and confusion in a 28-year-old man
   15 min
6. ADR case: Sore throat, fever and neutropenia in a patient on clozapine
   15 min
7. Quiz: Serious idiosyncratic neuropsychiatric and blood reactions: extrapyramidal effects, NMS and drug-induced neutropenia
   9 min