Heart failure digitalis

Digitalis Investigation Group (DIG) (1997) The effect of digoxin on mortality and morbidity in patients with heart failure. N Engl JMed 336 525-533... 

GC Oliver, R Tazman, R Frederickson. Influence of congestive heart failure on digoxin level. In O Storstein, ed. Symposium on Digitalis. Oslo Gyl-dendal Norsk Forlag, 1973, pp. 336-347. 

The outcome of this is to couple ATP hydrolysis with the vectorial transport of Na+ and K+ across the plasma membrane. The inhibition of the (Na+-K+)-ATPase by cardiac glycosides such as digitalis (an extract of foxglove leaves), which blocks the dephosphorylation of the E2-P form of the enzyme, is the basis for a number of steroid drags which are commonly prescribed for the treatment of congestive heart failure. 

Oral verapamil may precipitate heart failure. Control patients with milder ventricular dysfunction with digitalis or diuretics before verapamil, if possible. 

Congestive heart failure (CHF) For the treatment of mild to severe heart failure of ischemic or cardiomyopathic origin, in conjunction with digitalis, diuretics, and ACE inhibitors, to reduce the progression of disease. 

Heart failure - Usual initial dosage is 25 mg 3 times daily. After 50 mg 3 times daily is reached, delay further dosage increases, where possible, for at least 2 weeks to determine if a satisfactory response occurs. Most patients have had a satisfactory clinical improvement at 50 or 100 mg 3 times daily. Do not exceed a daily dose of 450 mg. Captopril should generally be used in conjunction with a diuretic and digitalis. 

Heart failure As adjunctive therapy with diuretics and digitalis, the recommended starting dose is 2.5 mg twice daily. The usual therapeutic dosing range for the treatment of heart failure is 2.5 to 20 mg/day given in 2 divided doses. The maximum daily dose is 40 mg. 

Ahmed A, Rich MW, Fleg JL, Zile MR, Young JB, Kitzman DW et al. Effects of digoxin on morbidity and mortality in diastolic heart failure the ancillary digitalis investigation group trial. Circulation 2006 114(5) 397-403. 

Fluid overload occurs commonly in patients with renal failure, often in the absence of associated heart disease. If salt and water intake is not controlled in the patient who is oliguric or anaemic, plasma volume and symptoms of congestive heart failure ensue. Hypertension and coronary heart disease with increasing age contributes to the congestive heart failure. Diuretics like loop-diuretics or metolazone may be of value. Digitalis should be used with caution in patients on dialysis as cardiac arrhythmias may ensue in patients receiving dialysis in the presence of hypokalemia. 

Digitalis functions to improve congestive heart failure by... 

D. Inhibition of Na-KATPase leads to an elevation of intracellular Na. This results in an increase in intracellular Ca" " and an enhanced myocardial contractibility. There is no definitive evidence that digitalis improves survival of patients in heart failure, but it clearly improves the symptoms of this condition. 

Historically, plant-based natural products have been a source of useful drugs. The analgesic opiates come from the poppy plant. Digitalis for congestive heart failure was first isolated from the foxglove plant. Various antibiotics (penicillin) and anticancer agents (taxol) are derived from natural product sources. There are numerous other examples. 

It is indicated in all grades of essential hypertension and renovascular hypertension where standard therapy is ineffective or inappropriate because of adverse effects and in congestive heart failure. It should be used as an adjunctive therapy with digitalis and/or diuretics. 

Digoxin is indicated in patients with heart failure and atrial fibrillation. It is also most helpful in patients with a dilated heart and third heart sound. It is usually given only when diuretics and ACE inhibitors have failed to control symptoms. Only about 50% of patients with normal sinus rhythm (usually those with documented systolic dysfunction) will have relief of heart failure from digitalis. Better results are obtained in patients with atrial fibrillation. If the decision is made to use a cardiac glycoside, digoxin is the one chosen in most cases (and the only one available in the USA). When symptoms are mild, slow loading (digitalization) with 0.125-0.25 mg per day is safer and just as effective as the rapid method (0.5-0.75 mg every 8 hours for three doses, followed by 0.125-0.25 mg per day). 

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