Advantages of Digitalis Therapy in Clinical HF
- Stood test of time (in use 228 years)
- Given orally, once a day
- Easily tolerated
- Side effects infrequent
- Has multiple actions: all mild
- Has multiple beneficial clinical effects ( Table 1)
- Inexpensive
- Reduces costs of treating heart failure
What are the side effects of digitalis?
- Uses. Digoxin is used to treat heart failure, usually along with other medications.
- Side Effects. Nausea, vomiting, headache, dizziness, loss of appetite, and diarrhea may occur.
- Precautions.
- Interactions.
What is digitalis used to treat?
Digoxin helps make the heart beat stronger and with a more regular rhythm. Digoxin is used to treat heart failure. Digoxin is also used to treat atrial fibrillation, a heart rhythm disorder of the atria (the upper chambers of the heart that allow blood to flow into the heart). Warnings
What is the effect of digitalis on heart rate?
Both may mildly strengthen your heart and reduce your heart rate slightly. Digitalis may also decrease oedema (swelling caused by the build-up of fluid). It’s especially useful in people with irregular heart rhythms, notably atrial fibrillation with a rapid heart rate.
What should the heart rate be before giving digoxin?
What is Digitalis Toxicity?
- Nausea, vomiting, fatigue
- Irregularities in heart rate and rhythm
- Decreased BP, pallor
- Neurological changes – confusion, lethargic, visual disturbances, seizures
- Anorexia, diarrhea
What is the effect of digitalis?
Digitalis produces an increase of blood flow, a decrease of vascular resistance, venodilation, and a decrease of central venous pressure and heart rate (Figure 1). The vasodilation is the result of an increase in cardiac output and direct baroreflex-mediated withdrawal of sympathetic vasoconstriction.
Why does digitalis increase heart contractility?
Digoxin induces an increase in intracellular sodium that will drive an influx of calcium in the heart and cause an increase in contractility. Cardiac output increases with a subsequent decrease in ventricular filling pressures. [2] AV Node Inhibition: Digoxin has vagomimetic effects on the AV node.
What is Digitalis purpurea used for?
Foxglove is most commonly used for heart failure and fluid build up in the body (congestive heart failure or CHF) and irregular heartbeat (atrial fibrillation).
Does digitalis lower blood pressure?
Conclusions: Digoxin significantly decreases diastolic blood pressure during overnight sleep in patients with congestive heart failure. This effect is likely to be caused by reduction of sympathetic activity or increase of parasympathetic activity.
Does digitalis decrease heart rate?
This parasympathomimetic action of digitalis reduces sinoatrial firing rate (decreases heart rate; negative chronotropy) and reduces conduction velocity of electrical impulses through the atrioventricular node (negative dromotropy).
What is the pharmacological action of digitalis on Normal heart?
Most textbooks of pharmacology and cardiology state that digitalis reduces the cardiac output of both the normal and the enlarged nonfailing heart (1-9) by as much as 20 to 35% (4).
What type of drug is digitalis?
Belonging to a group of drugs called cardiac glycosides, digitalis is most commonly used to restore adequate circulation in patients with congestive heart failure, particularly as caused by atherosclerosis or hypertension.
Is digitalis a positive Inotrope?
Furthermore, digitalis has a positive inotropic and antiarrhythmogenic effect. Specific binding sites for digitalis glycosides have been observed in erythrocytes, the myocardium and the central nervous system.
When should I take digitalis?
You can take digoxin with or without food, but it's best to take it at the same time each day. Most people take it in the morning after breakfast. You'll usually take it once a day. Swallow the tablets whole with a drink of water.
Is digitalis a diuretic?
Digitalis, when given to the healthy human subject in therapeutic doses and under experimental conditions laid down in this study seems to exert slight, if any, diuretic effect. The diuretic effect of digitalis in cases of cardiac failure with edema is uncertain; such effect may be marked, slight, or absent.
Is digitalis a beta blocker?
Beta-blockers, non-dihydropyridine calcium channel blockers (diltiazem, verapamil) and digitalis are the primary drugs used for ventricular rate control during AF.
How does digoxin affect heart rate?
Digoxin is a type of drug called a cardiac glycoside. Their function is to slow your heart rate down and improve the filling of your ventricles (two of the chambers of the heart) with blood.
What is digitalis used for?
For most of the 1800s, digitalis was used to treat a wide variety of diseases and disorders. In 1875, German chemist Oswald Schmiedeberg first isolated pure digitoxin from digitalis, leading others to extract and identify other glycosides from various species of digitalis. In 1957, digoxin was isolated from D. lanata and is now a major cardiac glycoside marketed in tablet form. Digitalis was admitted into the first edition of the Pharmacopeia of the United States (1820) and is currently recognized by all major pharmacopeias. In South America, preparations of the powdered leaves are used to relieve asthma, as sedatives, and as diuretic/cardiotonics. In India, an ointment containing digitalis glycosides is used to treat wounds and burns. Belcastro 2002, Feussner 2010, Morton 1997
What is digitalis glycoside used for?
In India, an ointment containing digitalis glycosides is used to treat wounds and burns. Belcastro 2002, Feussner 2010, Morton 1997.
How much digoxin is in Digitalis leaf?
Traditional dosage starts at 1.5 g of leaf divided into 2 daily doses. Purified digoxin is typically used at daily doses of 0.125 to 0.25 mg.
How much digitalis is toxic?
The incidence of digitalis toxicity has been estimated to range from 5% to 23%. More stringent dosing guidelines and monitoring techniques have dramatically reduced the incidence of therapeutic overdose.
What are the life threatening interactions with digoxin?
Many of the life threatening interactions occur as a result of elevated digoxin serum levels ( eg, amiodarone, cyclosporine, macrolide and tetracycline antibiotics, propafenone, quinidine, verapamil) or electrolyte disturbances (eg, diuretics).
When was digoxin first isolated?
In 1875, German chemist Oswald Schmiedeberg first isolated pure digitoxin from digitalis, leading others to extract and identify other glycosides from various species of digitalis. In 1957, digoxin was isolated from D. lanata and is now a major cardiac glycoside marketed in tablet form.
Where is Digitalis native to?
Many colors of flowers have been bred from digitalis, and they are rarely white. Digitalis is native to the British Isles, western Europe, and parts of Africa, but is found today as an ornamental plant throughout the world.
What is Digitalis genus?
A number of species of Digitalis genus are available, of which D.purpurea (purple foxglove) and D.lanata (Grecian foxglove) are the most common and abundant. Others include- D.thapsi (Spanish foxglove), D.lutea (straw foxglove).This biennial herb of Scrophulariaceae plant family was introduced into British medicine for treatment of dropsy by Botanist William Withering. It is commonly known as foxglove-deriving it name from the flowers which resemble the fingers (digits)of a glove. Other common names like Witch’s glove, Dead Man’s Bells etc signify its toxic nature. You can find this plant in Europe and North America while Holland and Eastern Europe are its commercial producers.
Is Digoxin better than Digitoxin?
Digoxin is more preferable to digitoxin by most of the physicians due to more toxic effects of digitoxin. Prior taking Digitalis preparations you must inform your doctor if you had been taking any other medicines like calcium supplements, diuretics or water pills or other drugs which are effective in the gastro-intestinal system. You should take oral medication of digitalis a couple of hours prior to or later to ingestion of foods which are high in fibers like oats, bran etc.In case of any allergic symptom noticed consult your doctor immediately. Do not use this medication without consultation of doctor. In pregnant and lactating women cardiac adverse effects are documented. Hence avoid digitalis.
Is digitalis a toxic drug?
Digitalis is a drug of low margin of safety which means that its clinically beneficial dose is riskily close to its toxic dose. It has a cumulative effect in body and gets slowly eliminated and therefore overdose during therapy is common. All parts of plant are toxic. Accidental ingestions in high dose have been proved lethal in both humans and animals . Toxicity may arise due to chronic overmedication, low level of potassium in body associated with diuretic use in heart failure, ailments destroying kidney functions etc. The symptoms of digitalis toxicity can be broadly categorized into two –
What is digitalis therapy?
Digitalis Therapy for Patients in Clinical Heart Failure. The most commonly used preparation of digitalis is digoxin, which is obtained from the leaves of Digitalis lanata, a common flowering plant called “foxglove.”. The words digitalis and digoxin in this article are used interchangeably.
How much digoxin toxicity is detected in the DIG trial?
In the DIG trial, “suspected digoxin toxicity” was diagnosed in 11.9% in the digoxin-treated group and 7.9% in the placebo groups. Hospitalization for “suspected digoxin toxicity” in the two groups was 2.0% and 0.9%, respectively. 25
What is the most commonly used preparation of digitalis?
The most commonly used preparation of digitalis is digoxin, which is obtained from the leaves of Digitalis lanata, a common flowering plant called “foxglove.” The words digitalis and digoxin in this article are used interchangeably. An exhaustive review published in 1996 1 cited a large number of references and had detailed data and descriptions of a large number of studies and all early trials. The present article summarizes those data but focuses on and emphasizes data collected since that time.
How long does vasocontriction last with ouabain?
3 The vasoconstriction is obviated by administering digoxin slowly over a period of 15 to 20 minutes 1; moreover, the vasoconstriction lasts up to 30 minutes. The seminal study of Mason and Braunwald 3 showed that in HF, the effects are different. Digitalis produces an increase of blood flow, a decrease of vascular resistance, venodilation, and a decrease of central venous pressure and heart rate ( Figure 1 ). The vasodilation is the result of an increase in cardiac output and direct baroreflex-mediated withdrawal of sympathetic vasoconstriction. The reduction of systemic vascular resistance in patients in HF has been repeatedly confirmed. 1
What is the effect of Digitalis on blood flow?
Digitalis produces an increase of blood flow, a decrease of vascular resistance, venodilation, and a decrease of central venous pressure and heart rate ( Figure 1 ). The vasodilation is the result of an increase in cardiac output and direct baroreflex-mediated withdrawal of sympathetic vasoconstriction.
Does digoxin slow down heart rate?
In patients with heart failure (HF), digoxin slows the ventricular rate (1) in sinus rhythm because of an improvement in HF and withdrawal of sympathetic stimulation and (2) in atrial fibrillation by increasing parasympathetic tone. The combination of digoxin and carvedilol is superior to digoxin or carvedilol alone. 2
Where does inotropic action occur?
The inotropic action occurs in both ventricles and in both atria. In the normal heart and in those with coronary artery disease and normal left ventricular (LV) systolic function, with digitalis the LV function curve is moved upward and to the left. 1 As a result, LV end-diastolic pressure and LV end-diastolic and end-systolic volumes are reduced, and there is an increase of LV ejection fraction (LVEF). 1
Clinical Overview
- Use
Digitalis has long been used as a treatment for heart failure in addition to a range of other traditional uses. The plant is cultivated as an ornamental. - Dosing
Digitalis leaf has a narrow therapeutic index, requiring close medical supervision for safe use. Traditional dosage starts at 1.5 g of leaf divided into 2 daily doses. Purified digoxin is typically used at daily doses of 0.125 to 0.25 mg.
Botany
- Digitalis is typically a biennial plant but may be annual or perennial depending on the species. It is characterized by a thick, cylindrical, downy stem that reaches a height of up to 2 m. Leaves form a thick rosette during the first year of growth. The leaves, which are woolly, veined, and covered with white hairs on the underside, have a very bitter taste. Flowers grow in the first or second year, de…
History
- Digitalis was one of the many herbal remedies used by the ancient Romans. Although its use for the treatment of heart failure has been traced back to 10th century Europe, digitalis was not widely used for this indication until its scientific investigation by British physician William Withering in the late 1700s. For most of the 1800s, digitalis was used to treat a wide variety of di…
Chemistry
- Ornamental strains of D. purpurea typically have low concentrations of active compounds. Leaves of wild varieties that have been used for medicinal purposes contain at least 30 different glycosides in total quantities ranging from 0.1% to 0.6%; these consist primarily of purpurea glycoside A (yielding digitoxin) and glycoside B, the precursor of gitoxin. Upon hydrolysis, digitox…
Uses and Pharmacology
- Cardiovascular effects
Cardiac glycosides possess positive inotropic effects due to inhibition of sodium-potassium adenosine triphosphatase, which allows calcium to accumulate in myocytes leading to enhanced cardiac contractility. These drugs also possess some antiarrhythmic activity, but will induce arrh…
Dosing
- Digitalis leaf has a narrow therapeutic index, requiring close medical supervision for safe use. Traditional dosage starts at 1.5 g of leaf divided into 2 daily doses. Purified digoxin is typically used at daily doses of 0.125 to 0.25 mg.Ebaid 2006, Hood 2004
Interactions
- There are numerous interactions with digoxin and digitalis glycosides, ranging from relatively minor (eg, cimetidine, triamterene) to life threatening. Many of the life threatening interactions occur as a result of elevated digoxin serum levels (eg, amiodarone, cyclosporine, macrolide and tetracycline antibiotics, propafenone, quinidine, verapamil) or electrolyte disturbances (eg, diuret…
Toxicology
- All parts of the plant are toxic. Animal toxicity occurs during grazing. Children have become ill by sucking the flowers or ingesting seeds or parts of the leaves. Deaths have been reported among people who drank tea made from digitalis mistakenly identified as comfrey, although the bitter taste often deters ingestion, and its emetic properties can induce vomiting, thereby limiting syst…
Index Terms
- Digitalis ambigua
- Digitalis ferriginea
- Digitalis grandiflora
- Digitalis lutea
Disclaimer
- This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this pro…