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)


Mineralocorticoids and mineralocorticoid antagonists


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


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


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



Miscellaneous antifungal medications

Anthelmintic medications


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


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


Opioid agonists, mixed agonist-antagonists and partial agonists

Antigout medications


Medication overdoses and toxicities: Pathology review

USMLE® Step 1 questions

0 / 9 complete


USMLE® Step 1 style questions USMLE

of complete

A 57-year-old man comes to his primary care physician for evaluation of new onset blood in his urine. The patient first noticed the blood early this morning. He does not have dysuria or abdominal or suprapubic pain. He had a mitral valve replacement last year, and he is currently taking warfarin. Vital signs are within normal limits. The patient’s INR is 3.5. Further history is most likely to reveal administration of which of the following medications?


Content Reviewers

Antonella Melani, MD


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.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Katzung & Trevor's Pharmacology Examination and Board Review,10th Edition" McGraw Hill Professional (2012)
  4. "Anticholinesterases and anticholinergic drugs" Continuing Education in Anaesthesia Critical Care & Pain (2004)
  5. "Paracetamol and fever management" Journal of the Royal Society for the Promotion of Health (2008)
  6. "Chemical and Mechanical Alternatives to Leech Therapy: A Systematic Review and Critical Appraisal" Journal of Reconstructive Microsurgery (2011)
  7. "Clinical Laboratory Medicine" Lippincott Williams & Wilkins (2002)

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