Digoxin with amiodarone

Of 26 fetuses with hydrops fetalis and supraventricular tachycardias, 25 received transplacental drug therapy prenatal conversion occurred in 15 (82). Nine fetuses were converted to sinus rhythm using either flecainide (n = 7) or amiodarone (n = 2) as first-line therapy, while digoxin either alone or in association with sotalol failed to restore sinus rhythm in all cases. After first-line therapy, supraventricular tachycardia persisted in 10 fetuses, nine of whom received amiodarone alone or in association with digoxin as second-line therapy, and five of whom converted to sinus rhythm. Of 11 neonates who received amiodarone in utero, two developed raised thyroid stimulating hormone concentrations on postnatal days 3-4 they received thyroid hormone and had normal outcomes. 

JP is a 35-year-old woman who presents with an uncomplicated UTI. She has a history of cardiac arrhythmias for which she takes amiodarone and digoxin. Her allergies include anaphylaxis to sulfa medications. Which of the following medications would be the best choice to treat her UTI ... 

A 56-year-old man with hypertension suffered a 62% total body surface area burn (day 0) and on day 4 developed atrial fibrillation with a rapid ventricular rate, which was treated with amiodarone and digoxin. After pyloroplasty for a bleeding ulcer on day 20, he developed a postoperative ileus and was given metoclopramide 20 mg intravenously every 6 hours. Beginning on day 54, he started to have episodes of bradycardia and asystole. Some episodes required atropine and others resolved spontaneously. Some converted initially to a junctional rhythm, but all ultimately reverted to sinus tachycardia. Digoxin and metoclopramide were withdrawn and several hours later the bradydysrhythmias stopped. 

Neurodevelopment delay has been attributed to long-term amiodarone exposure in a child with fetal junctional reciprocating tachycardia and normal thyroid function [39" ]. A refractory persistent tachycardia was treated in utero with digoxin 0.5 mg/day until delivery and amiodarone 100 mg/day from 26 to 35 weeks of gestation. The baby was delivered at 38 weeks, weighed 3550 g, and had normal acid-base balance. 

Amiodarone increases the hypoprothrombinemic response to warfarin (an oral anticoagulant) by reducing its metabolism. Patients receiving digoxin may undergo an increase in serum digoxin concentrations when amiodarone is added to the treatment regimen. Amiodarone interferes with hepatic and renal elimination of flecainide, phenytoin, and quinidine. 

Quinidine inhibits the tubular secretion of digoxin which consequently raises the plasma digoxin concentration, which may be associated with toxicity. Certain other drugs also increase the digoxin concentration like verapamil, amiodarone, spironolactone etc. 

Medications such as P-blockers, calcium channel blockers, digoxin, and amiodarone can be used to control cardiac conduction abnormalities (arrhythmias), and a pacemaker may be inserted to combat heart failure. The general supportive care measures used in acute stroke syndromes also should be followed. Death in patients with MELAS is usually the result of cardiac failure, pulmonary embolus, or renal failure. 

Caution with haloperidol, amiodarone, digoxin, octreotide Increased risk of hypotension, bradycardia, and cardiac conduction abnormalities... 

Amiodarone inhibits the renal tubular secretion of digoxin (SEDA-22, 201) and it has also been suggested that it increases its absorption (SEDA-10, 144) (SEDA-12,150). This interaction has also been reported with acetyldigoxin (SEDA-18,198) (221). 

When salbutamol is used to arrest premature labor, effective doses are likely to produce mild fetal tachycardia (for example an increase of 20/minute) (23). In one case, supraventricular tachycardia occurred in the fetus in the 34th week of pregnancy after the mother had been treated with salbutamol digoxin with and without propranolol was ineffective, but amiodarone controlled the tachycardia (24). 

B Because this patient has asthma and is wheezing, calcium channel blockers are the drug class of choice. Unlike beta-blockers and adenosine, they do not cause bronchospasm. Beta-blockers and adenosine should be used cautiously in patients with obstructive lung disease, and use should be avoided in patients with asthma. Digoxin is not contraindicated, but it is not the drug of choice due to its slow onset. Amiodarone is indicated for ventricular arrhythmias, but not PSVT. 

Serious ingestions require cardiac monitoring in an intensive-care setting. Hypotension may be resistant to dopamine and dobutamine. Norepinephrine can also be used. Bradycardia can be treated with atropine and a temporary pacemaker as needed. Digoxin-specific FAB antibody fragments have been used with some success for cardiac conduction abnormalities after a yew exposure. If no contraindication, lido-caine, amiodarone, or procainamide may be used for ventricular dysrhythmias. 

Clinically important, potentially hazardous interactions with aminophylline, amiodarone, digoxin, prednisolone... 

Clinically important, potentially hazardous interactions with alcohol, amiodarone, beta-blockers, cimetidine, donidine, digoxin, diltiazem, disopyramide, ephedrine, epinephrine, ergot alkaloids, guanethidine, halothane, isoprenaline, lidocaine, noradrenaline, NSAIDs, phenylephrine, quinidine, reserpine, verapamil... 

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