Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Elevated serum level of digoxin Gastrointestinal symptoms with altered color vision Cardiac arrhythmias, especially premature ventricular beats and heart block +++ GENERAL CONSIDERATIONS ++ May occur in up to 10% of patients hospitalized for heart failure Common clinical features: – Nausea and vomiting – Anorexia – Malaise – Drowsiness – Headache – Insomnia – Altered color vision – Arrhythmia Almost all known cardiac arrhythmias may be caused by digoxin toxicity Toxicity is facilitated by hypokalemia – Severe digoxin toxicity causes hyperkalemia secondary to paralysis of Na+/K+ exchange pump Diuretics cause hypokalemia and thus facilitate digitalis toxicity Other drugs, such as amiodarone and verapamil, increase digitalis serum levels +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Nausea, vomiting, diarrhea, anorexia Drowsiness, malaise, headache, altered color vision Palpitation +++ PHYSICAL EXAM FINDINGS ++ Bradycardia is common Tachycardia can occur +++ DIFFERENTIAL DIAGNOSIS ++ Arrhythmias secondary to underlying heart disease Gastrointestinal disorders Central nervous system disorders Ingestion of digoxin-like compounds, such as bufadienolides found in some Chinese aphrodisiacs, and digitalis compounds found in plants, such as foxglove and oleander +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ Low potassium (common) Reduced renal function—may contribute Creatinine level: elevated Digoxin level: outside therapeutic range +++ ELECTROCARDIOGRAPHY ++ Characteristic downward scooped ST segment Premature ventricular contractions First-, second-, and third-degree heart block Atrial tachycardia with 2:1 block Alternating ventricular tachycardia Junctional tachycardia, often with atrial fibrillation +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Suspected digoxin toxicity Serious ventricular arrhythmias Symptomatic bradycardia +++ HOSPITALIZATION CRITERIA ++ Serious ventricular arrhythmias Second- or third-degree heart block Need for digoxin antibody therapy +++ MEDICATIONS ++ Reversal of symptoms or cessation of arrhythmia occurs after withdrawal of digoxin for 48 hours Ventricular arrhythmia may require lidocaine 100 mg IV Antidigoxin immunotherapy may be used, particularly if hyperkalemia is present +++ MONITORING ++ ECG monitoring in hospital +++ ONGOING MANAGEMENT +++ HOSPITAL DISCHARGE CRITERIA ++ Resolution of problem Digoxin level in therapeutic range +++ FOLLOW-UP ++ Serum digoxin level and ECG 10–14 days after new dosage +++ COMPLICATIONS ++ Cardiac arrest Syncope +++ PROGNOSIS ++ Excellent with appropriate treatment +++ PREVENTION ++ Reduce digoxin dose if renal function decreases Reduce digoxin dose when starting drugs that interact with it and recheck digoxin levels in 2 weeks ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.