See also: [[Classic tox ECGs]] [Murray Digoxin Acute overdose](x-devonthink-item://C8AE745C-C96E-4AEF-9010-D441840C6DF4?page=245) [Austin Digoxin Acute poisoning](x-devonthink-item://832BDA2B-AA34-49B5-93F6-BD35F9CCBB39) [bear dogixin vs lithium table](bear://x-callback-url/open-note?id=220FA6A3-A8B6-4261-9871-5804062DF44B) > [!Key points] > - **risk_dose::** >10mg in adult or 4mg in child OR >10 times daily dose > > - ECG with "digoxin effect" doesn't mean toxicity: tox ECG would have bradycardia, AV blocks, ectopics > > - **symptoms:** > - GI – nausea, vomiting, abdo pain > - CVS – bradycardia including heart block, slow AF, dysrhythmias including ectopic, bigeminy, SVT, VT, hypotension > - CNS – lethargy, confusion, delirium > - Serum K > 5.5 mmol/L ==predicts 100% mortality without digoxin immune Fab==. > > **Antidote**:: [[Digibind]], insulin/dextrose, atropine > [!Summary] > *Acute digoxin toxicity manifests with early onset of vomiting and [[hyperkalemia]] and can progress to life-threatening cardiac dysrhythmias and cardiovascular collapse. Cardiovascular complications are refractory to conventional resuscitation measures. [[Digibind|Digoxin immune Fab]] is a highly effective antidote.* > > *Consider the diagnosis of **chronic digoxin intoxication** in any patient on digoxin who presents with collapse, hypotension, bradycardia, dysrhythmia, gastrointestinal complaints, altered mental status or general deterioration.* > notes: > Can cause ventricular fibrillation a few hours later if given to someone with WPW AF # Mechanism - Digoxin inhibits the membrane Na+–K+-ATPase pump, leading to a reduced sodium gradient and reduced calcium extrusion from the cell. - This results in increased concentrations of intracellular calcium (**enhanced automaticity**, positive inotropic effect) and extracellular potassium. - Digoxin also **enhances vagal tone**, resulting in decreased sinoatrial and atrioventricular node (AV) conduction velocities. # Clinical Features ## Acute Overdose - nausea and vomiting develop 2-4 hours after ingestion - peak serum levels at 6 hours - death secondary to cardiovascular collapse at 8-12 hours **GI effects** - nausea, vomiting, abdo pain **Cardio** - bradycardias - 1st, 2nd, or 3rd deg heart block - slow AF rate <30 - increased automaticity - ventricular ectopics - SVT with AV block - [[Ventricular Tachycardia]] - hypotension - AF + complete heart block (“regularised atrial fibrillation”) **CNS** - lethargy **bloods** - [[hyperkalemia|hyper-K]] > Perform serum digoxin level 4 hours post-ingestion and then every 2 hours until definitive treatment or toxicity resolving. ## Chronic overdose > It is often difficult to determine whether the unwell patient with an elevated serum digoxin level has digoxin toxicity or another cause for the observed clinical features. > **Serum digoxin level** > The diagnosis of chronic digoxin intoxication is based on a steady-state level 6 or more hours after the last dose. > Serum digoxin levels near the therapeutic range of 0.5–1.0 ng/mL (0.6–1.3 nmol/L), correlate poorly with severity of intoxication **Features** ==Decreased visual acuity== - Aberration of colour vision (chromatopsia) - Yellow haloes (xanthopsia). ![[Pasted image 20230828014200.png]] # Digoxin overdose ECG - SVT - (due to increased automaticity) - **Slow ventricular response** (due to decreased AV conduction - frequent PVCs (the most common abnormality), including ventricular bigeminy and trigeminy - Slow AF - “Regularised” AF: AF with complete heart block and a junctional or ventricular escape rhythm - sinus bradycardia ![[Pasted image 20241113145600.png]] ## digoxin effect ECG (not OD) Presence of digoxin effect is NOT a marker of toxicity! - Downsloping ST depression with a characteristic “reverse tick” or “Salvador Dali sagging” appearance - Flattened, inverted, or biphasic T waves - QT shortening ![[Pasted image 20241113145632.png]] ![[Pasted image 20241113145651.png]] # treatment 1. hyperkalemia tx 1. ==Do NOT give calcium== (probably fine, magnesium better alternative) 2. sodium bicarb 100mEq IV (1mEq/kg in kids) 3. insulin/dextrose (50mL 50% + 10 u (kids: 0.1units/kg insulin and 2mL/kg 10% dextrose) 2. AV block tx 1. 600mcg atropine IV up to 1.8 mg 3. ventricular tachydysrhythmias 1. 1mg/kg lignocaine IV max 100mg over 2 min or magnesium 2. Do NOT cardiovert because it can precipitate ventricular arrhythmias 4. [[Digibind|Digoxin immune Fab]] 1. 20 vials in arrest 2. 10 vials if unstable 3. 5 vials otherwise (or calculate requirements) 5. Perform serum digoxin level 4 hours post-ingestion and then every 2 hours until definitive treatment or toxicity resolving. # indications for digibind - Cardiac arrest - Life threatening cardiac arrhythmias - Ingestion of >10mg in an adult or >4mg in a child - Serum digoxin level >15nmol/mL - Serum K > 5mmol/L ==resuscitate at least 30 min after giving digibind== # Related Questions ## digoxin toxicity - [ ] 6Q: [Abnormal ECG of unwell elderly man](x-devonthink-item://CA0CC973-6102-4C33-AB59-A43A87724DF0?page=16) -- [Answer](x-devonthink-item://9F437E5A-02D4-43FC-B795-5386EDE954F3?page=14) -- [prop](x-devonthink-item://281EC7A9-8E5A-461A-AA34-3FF490AA0EC2?page=3) - [ ] 34Q: [Digoxin toxicity](x-devonthink-item://5DD7C01C-AB9B-4F0E-9CC4-266700BD94E8?page=5) -- [Answer](x-devonthink-item://7CE81625-E4A6-40C1-BAEB-7E44C75B1E60?page=6)