Medication overdoses and toxicities: Pathology review
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Medication overdoses and toxicities: Pathology review
Medical and surgical emergencies
Cardiology, cardiac surgery and vascular surgery
Advanced cardiac life support (ACLS): Clinical (To be retired)
Supraventricular arrhythmias: Pathology review
Ventricular arrhythmias: Pathology review
Heart blocks: Pathology review
Coronary artery disease: Clinical (To be retired)
Heart failure: Clinical (To be retired)
Syncope: Clinical (To be retired)
Pericardial disease: Clinical (To be retired)
Valvular heart disease: Clinical (To be retired)
Chest trauma: Clinical (To be retired)
Shock: Clinical (To be retired)
Peripheral vascular disease: Clinical (To be retired)
Leg ulcers: Clinical (To be retired)
Aortic aneurysms and dissections: Clinical (To be retired)
Cholinomimetics: Direct agonists
Cholinomimetics: Indirect agonists (anticholinesterases)
Muscarinic antagonists
Sympathomimetics: Direct agonists
Sympatholytics: Alpha-2 agonists
Adrenergic antagonists: Presynaptic
Adrenergic antagonists: Alpha blockers
Adrenergic antagonists: Beta blockers
ACE inhibitors, ARBs and direct renin inhibitors
Loop diuretics
Thiazide and thiazide-like diuretics
Calcium channel blockers
cGMP mediated smooth muscle vasodilators
Class I antiarrhythmics: Sodium channel blockers
Class II antiarrhythmics: Beta blockers
Class III antiarrhythmics: Potassium channel blockers
Class IV antiarrhythmics: Calcium channel blockers and others
Positive inotropic medications
Antiplatelet medications
Dermatology and plastic surgery
Blistering skin disorders: Clinical (To be retired)
Bites and stings: Clinical (To be retired)
Burns: Clinical (To be retired)
Endocrinology and ENT (Otolaryngology)
Diabetes mellitus: Clinical (To be retired)
Hyperthyroidism: Clinical (To be retired)
Hypothyroidism and thyroiditis: Clinical (To be retired)
Parathyroid conditions and calcium imbalance: Clinical (To be retired)
Adrenal insufficiency: Clinical (To be retired)
Neck trauma: Clinical (To be retired)
Insulins
Mineralocorticoids and mineralocorticoid antagonists
Glucocorticoids
Gastroenterology and general surgery
Abdominal pain: Clinical (To be retired)
Appendicitis: Clinical (To be retired)
Gastrointestinal bleeding: Clinical (To be retired)
Peptic ulcers and stomach cancer: Clinical (To be retired)
Inflammatory bowel disease: Clinical (To be retired)
Diverticular disease: Clinical (To be retired)
Gallbladder disorders: Clinical (To be retired)
Pancreatitis: Clinical (To be retired)
Cirrhosis: Clinical (To be retired)
Hernias: Clinical (To be retired)
Bowel obstruction: Clinical (To be retired)
Abdominal trauma: Clinical (To be retired)
Laxatives and cathartics
Antidiarrheals
Acid reducing medications
Hematology and oncology
Blood products and transfusion: Clinical (To be retired)
Venous thromboembolism: Clinical (To be retired)
Anticoagulants: Heparin
Anticoagulants: Warfarin
Anticoagulants: Direct factor inhibitors
Antiplatelet medications
Thrombolytics
Infectious diseases
Fever of unknown origin: Clinical (To be retired)
Infective endocarditis: Clinical (To be retired)
Pneumonia: Clinical (To be retired)
Tuberculosis: Pathology review
Diarrhea: Clinical (To be retired)
Urinary tract infections: Clinical (To be retired)
Meningitis, encephalitis and brain abscesses: Clinical (To be retired)
Bites and stings: Clinical (To be retired)
Skin and soft tissue infections: Clinical (To be retired)
Protein synthesis inhibitors: Aminoglycosides
Antimetabolites: Sulfonamides and trimethoprim
Antituberculosis medications
Miscellaneous cell wall synthesis inhibitors
Protein synthesis inhibitors: Tetracyclines
Cell wall synthesis inhibitors: Penicillins
Miscellaneous protein synthesis inhibitors
Cell wall synthesis inhibitors: Cephalosporins
DNA synthesis inhibitors: Metronidazole
DNA synthesis inhibitors: Fluoroquinolones
Herpesvirus medications
Azoles
Echinocandins
Miscellaneous antifungal medications
Anthelmintic medications
Antimalarials
Anti-mite and louse medications
Nephrology and urology
Hypernatremia: Clinical (To be retired)
Hyponatremia: Clinical (To be retired)
Hyperkalemia: Clinical (To be retired)
Hypokalemia: Clinical (To be retired)
Metabolic and respiratory acidosis: Clinical (To be retired)
Metabolic and respiratory alkalosis: Clinical (To be retired)
Toxidromes: Clinical (To be retired)
Medication overdoses and toxicities: Pathology review
Environmental and chemical toxicities: Pathology review
Acute kidney injury: Clinical (To be retired)
Kidney stones: Clinical (To be retired)
Adrenergic antagonists: Alpha blockers
Neurology and neurosurgery
Stroke: Clinical (To be retired)
Seizures: Clinical (To be retired)
Headaches: Clinical (To be retired)
Traumatic brain injury: Clinical (To be retired)
Neck trauma: Clinical (To be retired)
Lower back pain: Clinical (To be retired)
Spinal cord disorders: Pathology review
Anticonvulsants and anxiolytics: Barbiturates
Anticonvulsants and anxiolytics: Benzodiazepines
Nonbenzodiazepine anticonvulsants
Migraine medications
Osmotic diuretics
Antiplatelet medications
Thrombolytics
Opioid agonists, mixed agonist-antagonists and partial agonists
Opioid antagonists
Pulmonology and thoracic surgery
Asthma: Clinical (To be retired)
Chronic obstructive pulmonary disease (COPD): Clinical (To be retired)
Venous thromboembolism: Clinical (To be retired)
Acute respiratory distress syndrome: Clinical (To be retired)
Pleural effusion: Clinical (To be retired)
Pneumothorax: Clinical (To be retired)
Chest trauma: Clinical (To be retired)
Bronchodilators: Beta 2-agonists and muscarinic antagonists
Pulmonary corticosteroids and mast cell inhibitors
Rheumatology and orthopedic surgery
Joint pain: Clinical (To be retired)
Anatomy clinical correlates: Clavicle and shoulder
Anatomy clinical correlates: Axilla
Anatomy clinical correlates: Arm, elbow and forearm
Anatomy clinical correlates: Wrist and hand
Anatomy clinical correlates: Median, ulnar and radial nerves
Anatomy clinical correlates: Bones, joints and muscles of the back
Anatomy clinical correlates: Hip, gluteal region and thigh
Anatomy clinical correlates: Knee
Anatomy clinical correlates: Leg and ankle
Anatomy clinical correlates: Foot
Acetaminophen (Paracetamol)
Non-steroidal anti-inflammatory drugs
Glucocorticoids
Opioid agonists, mixed agonist-antagonists and partial agonists
Antigout medications
Assessments
Medication overdoses and toxicities: Pathology review
USMLE® Step 1 questions
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Transcript
Content Reviewers
Antonella Melani, MDContributors
Sam Gillespie, BSc
Evan Debevec-McKenney
Filip Vasiljević, MD
A 19 year old young man named Cameron is brought to the emergency room by his father, who found Cameron vomiting next to a half-empty bottle of aspirin. Cameron tells you that he has a headache and is hearing a weird ringing noise. You decide to perform a blood test, which reveals that Cameron has metabolic acidosis.
Later that day, 32 year old Adaline presents in the emergency room due to nausea, vomiting, and slurred speech. Adaline reports that she has the flu and has been taking ibuprofen for the last couple of days. You notice that Adaline is very thirsty, and she also keeps going to the restroom to urinate. Her history reveals that she was diagnosed with bipolar disorder a few years ago, and is currently under treatment with lithium.
Based on their history and presentation, both Cameron and Adaline seem to have some type of medication overdose or toxicity. An overdose refers to taking too much of a substance, and can result in toxicity, which refers to how harmful that substance can be to the body.
Now, let’s go over some pharmacology basics. The therapeutic index, or TI for short, is a quantitative measurement of a drug’s dosing and its safety. For your exams, you should know that the TI is calculated as the ratio of the median toxic dose or TD50, which is the dose that causes a toxic response in 50% of the population, over the median effective dose or ED50, which is the dose that causes a therapeutic effect in 50% of the population.
Now, if the test question gives you a median lethal dose or LD50 for short instead of TD50, don’t panic! These two can be used interchangeably in the formula, but keep in mind that TD50 refers to human clinical trials, while LD50 refers to animal studies, and is defined as the dose that causes death in 50% of tested animals.
The important thing to note here is that medications with a wide therapeutic index are safer, since their toxic dose is much higher than their effective dose. On the flip side, medications with a narrow therapeutic index are more dangerous, since they have close toxic and effective doses.
Now, in contrast to the therapeutic index, there is the therapeutic window, which is defined as the range of blood concentrations at which a medication can give therapeutic effects while avoiding toxicity. The therapeutic window refers to any blood concentration of a given drug that’s between two parameters. The first one is minimum effective concentration or MEC, which refers to the minimum concentration that has therapeutic effects. The other one is minimum toxic concentration or MTC, which refers to the minimum concentration that has toxic effects. Everything between these two concentrations represents the therapeutic window.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Katzung & Trevor's Pharmacology Examination and Board Review,10th Edition" McGraw Hill Professional (2012)
- "Anticholinesterases and anticholinergic drugs" Continuing Education in Anaesthesia Critical Care & Pain (2004)
- "Paracetamol and fever management" Journal of the Royal Society for the Promotion of Health (2008)
- "Chemical and Mechanical Alternatives to Leech Therapy: A Systematic Review and Critical Appraisal" Journal of Reconstructive Microsurgery (2011)
- "Clinical Laboratory Medicine" Lippincott Williams & Wilkins (2002)
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