The preparations were included in successive editions of the Danish pharmacopoeia, some of the tinctures already in , i. Isolation of cardiac glycosides from digitalis, strophanthus and squill and determination of their chemical structures initiated biochemical and pharmacological studies.
The scientific advances led to an understanding of cardiac muscle contractility and the Na,K pump as the cellular receptor for the inotropic action of digitalis. Examination of putative endogenous ligands to the receptor revealed some endogenous cardiac glycosides of similar or identical structures as those found in digitalis, strophanthus and squill.
Increased concentrations of these glycosides are found in patients with heart failure. Further investigations are needed to determine whether the secretion of glycosides might be a physiologic response to a diminished cardiac output. Withering found that the ingredient in the tea was foxglove and the active ingredient that had cured the woman was digitalis.
That same year he published, An Account of the Foxglove. This book propelled digitalis to the forefront of treatments for the heart. The English used foxgloves for many medicinal ailments including coughs, epilepsy and swollen glands. One of the curious stories associated with the plant involves Vincent Van Gogh who was believed to have taken the drug for his epilepsy.
Foxgloves are difficult to grow from seed and do not transplant well. It often takes years to establish a healthy grouping of the plants. It is recommended that seed be planted in the fall, but it can also be planted in the early spring.
During the first year, if the seed germinates, it will form a rosette or low mound sometimes 10 inches in diameter. Seed can remain dormant in the ground for years so do not be surprised if little or no germination results from the initial seeding.
Seed needs light to germinate so just press the seed into the moist soil, but do not cover it. Plants should be thinned to inches. Foxgloves love heavy feeding with manure or a tea made from comfrey leaves. Blooms only last for a week to 10 days. The plants bloom in July. Your Email required. Your Message. Search for:.
Digoxin has been around for centuries, but its use has been limited by several factors. Because of its narrow therapeutic window, digoxin requires close monitoring. Also, two major drawbacks of digoxin are its adverse effects AEs and multiple drug interactions. Despite these limitations, digoxin still plays a role in therapy for HF, AF, and several off-label uses.
It is considered adjunctive therapy, rather than first-line therapy, for these indications. It is used mainly as add-on therapy in AF patients whose heart rates are not adequately controlled on beta-blockers alone.
In CHF, contractility is decreased, which in turn reduces cardiac output. Digoxin is effective in patients with CHF because of its positive inotropic properties. Although studies have shown that digoxin reduces hospitalizations and improves symptoms of HF, it has not been proven to decrease mortality.
One double-blind, controlled trial of digoxin for CHF treatment randomized subjects with cardiac dysfunction to digoxin or placebo for 7 weeks. Cardiac function, as measured by ejection fraction EF , was significantly improved in digoxin patients. Digoxin may also be considered in patients with stage C HF structural heart disease with prior or current symptoms of HF or stage D HF HF symptoms at rest and recurrent hospitalizations despite therapy. Although digoxin is prescribed for patients with HF and AF, concomitant beta-blocker therapy is usually more effective at controlling ventricular response, particularly during exercise.
The initial dosage of digoxin is 0. The target serum level of digoxin in HF is 0. Digoxin has been shown effective for decreasing HF symptoms, and its effect on morbidity and mortality has been assessed as well.
The primary outcome was mortality; secondary outcomes were a composite of mortality from cardiovascular causes, death from worsening HF, and hospitalization for other causes digoxin toxicity. In the intent-to-treat analysis, there were 1, deaths in the digoxin group and 1, deaths in the placebo group Fewer digoxin patients than placebo patients were hospitalized and 1,, respectively; risk ratio 0.
Also, the risk associated with the combined outcome of death due to worsening HF or hospitalization was lower in the digoxin group 1, vs. The conclusion was that although digoxin had no effect on overall mortality, it significantly decreased the overall number of hospitalizations attributed to worsening HF.
AF is a common arrhythmia in which irregular electrical impulses are conducted through the heart. These irregular electrical impulses lead to uncoordinated and inefficient heart contractions. As a result, blood pools in the heart, increasing the likelihood of a blood clot, which may lead to serious consequences such as myocardial infarction or stroke. AF can be managed by utilizing either rate or rhythm control agents.
Digoxin exhibits its benefit in AF by controlling the heart rate. One multicenter, randomized, double-blind, crossover trial evaluated the benefit of digoxin versus placebo in 43 patients with paroxysmal AF.
The study endpoint was time to occurrence of one or two AF episodes as documented by patient-activated monitors. The median time to two episodes was The median time to one episode was 3.
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