<unk>  level
Only useful prior to administration of Fab (otherwise becomes falsely elevated)
Chemistry
Urine output
ECG (serial)
PVCs most common arrhythmia
May see "regularized AF" on ECG where junctional escape rhythm takes over secondary to complete AV block
Atach/Aflutter with slow conduction
Only useful prior to administration of Fab (otherwise becomes falsely elevated)
PVCs most common arrhythmia
May see "regularized AF" on ECG where junctional escape rhythm takes over secondary to complete AV block
Atach/Aflutter with slow conduction
Must use H&P and labs in combination; no single element excludes or confirms the diagnosis<unk>  level
Normal = 0.5-2 ng/mL (ideal = 0.7-1.1)
May have toxicity even with "therapeutic" levels (especially with chronic toxicity)
Measure at least 6hr after acute ingestion (if stable); immediately for chronic ingestion
Steady state level (6-8 hours after ingestion) and not peak level is used to guide therapy
If measure before this may be falsely elevated due to incomplete drug distribution
Not practical to wait 6-8 hours for intervention so clinical picture should guide decision making
Potassium level
Acute toxicity: Degree of Hyperkalemia correlates with degree of toxicity
Historical studies show K+ >5.5 mEq/L 100% mortality; K+ < 5 mEq/L 100% Survival 
Chronic toxicity: K+ may be normal/low (concomitant diuretic use), or high (renal failure)
Hypokalemia sensitizes myocardium to<unk>  
Magnesium level
hypomagnesemia can enhance<unk> 's effects
Normal = 0.5-2 ng/mL (ideal = 0.7-1.1)
May have toxicity even with "therapeutic" levels (especially with chronic toxicity)
Measure at least 6hr after acute ingestion (if stable); immediately for chronic ingestion
Steady state level (6-8 hours after ingestion) and not peak level is used to guide therapy
If measure before this may be falsely elevated due to incomplete drug distribution
Not practical to wait 6-8 hours for intervention so clinical picture should guide decision making
May have toxicity even with "therapeutic" levels (especially with chronic toxicity)
Steady state level (6-8 hours after ingestion) and not peak level is used to guide therapy
If measure before this may be falsely elevated due to incomplete drug distribution
Not practical to wait 6-8 hours for intervention so clinical picture should guide decision making
Acute toxicity: Degree of Hyperkalemia correlates with degree of toxicity
Historical studies show K+ >5.5 mEq/L 100% mortality; K+ < 5 mEq/L 100% Survival 
Chronic toxicity: K+ may be normal/low (concomitant diuretic use), or high (renal failure)
Hypokalemia sensitizes myocardium to<unk>  
Historical studies show K+ >5.5 mEq/L 100% mortality; K+ < 5 mEq/L 100% Survival 
Hypokalemia sensitizes myocardium to<unk>  
hypomagnesemia can enhance<unk> 's effects
Digoxin toxicity
Cardiac
Beta-blocker toxicity
Inferior MI 
Amiodarone pulmonary toxicity
Sick sinus syndrome
Clonidine toxicity
Neurocardiogenic/reflex-mediated