The term digitalis is used for drug preparations which contain cardiac glycosides, that are extracted from the dried leaves of the foxglove plant (scientifical name – Digitalis purpurea) and used to strengthen contractions of the heart muscle.
Although the parts of the Foxglove plant can be used for medicine, it is unsafe for self-medication, plus, all parts of the plant are poisonous.
Foxglove was brought to the US by European migrants a few centuries ago. It reaches to about 5 feet tall, with many large, thick, hairy leaves at the base and tube-shaped, spotted, purple flowers. The variety grown in gardens varies in color from white to a deep rose.
The medicinal effects of the Foxglove extract on the heart were first observed by William Withering, an English geologist, botanist, chemist, and physician, in the late 18th century. He experimented with the extract in humans and fowls.
In a treatise entitled – “The Foxglove and an Account of its Medical Properties, with Practical Remarks on Dropsy, ” he reported his results. Withering predicted that Foxglove could be converted in some type of medicine for the heart.
This medication works directly on the heart muscle to regulate and strengthen the heartbeat. Also, it is used to treat certain heart conditions, such as – heart rhythm problems (atrial arrhythmias) and congestive heart failure (CHF). In addition, it can reduce swelling in the ankles and hands as well as it can increase blood flow throughout the human body.
Moreover, it may be used to convert paroxysmal supraventricular tachycardia to sinus rhythm. Also, this medicine should be used for slowing a rapid ventricular rate in atrial flutter and atrial fibrillation (an irregular rapid heart rate) unassociated with the preexcitation syndrome.
Common side effects include:
- swelling of the feet and lower legs;
- fatigue and muscle weakness;
- fainting, drowsiness, or dizziness;
- loss of appetite;
- bloody vomit;
- pounding heartbeat;
- severe stomach pain;
- slow heartbeat.
Very rare side effects may include:
- blood in the stools or urine;
- tarry stools;
- shortness of breath;
- unusual tiredness;
- bleeding gums;
- troubled breathing;
- chest pain;
- unusual bleeding;
- small raised lesions on the skin;
- pinpoint red spots on the skin.
People with heart failure who use this type of medicine are frequently given medicines (better known as diuretics) which remove excess fluid from the body.
The problem is that most of these medicines can cause potassium loss, and a deficiency of potassium in the body can considerably increase the risk of the above side effects. Also, these side effects may occur in people who have a low level of magnesium.
Drug interactions with this heart medicine can occur with drugs, like – propranolol as well as cholestyramine and colestipol.
This drug is extracted from the leaves of Foxglove plant. Trade names for this medicine include Digitek, Lanoxin, and Lanoxicaps. Also, it can be found as a generic medication.
It increases the force of contraction of the muscle of the heart by inhibiting the activity of an enzyme which controls the movement of sodium, calcium, and potassium into the heart muscle. This increases your heart strength, affects the heart rhythm, and removes excess water from the human body.
Moreover, this drug is used to treat a heart rhythm disorder of the atria (atrial fibrillation) and heart failure.
This medicine can be administered as a gelatin capsule, tablet, intravenous injection, or elixir (mainly for children). As a tablet, it is given by mouth and it reaches a peak concentration in about three hours at a level of 80 percent of the same dose given intravenously.
It is 60 to 75 percent absorbed from tablets, and it has a dominant half-life of 34 hours. This drug is usually excreted via urine.
Common side effects may include:
- ventricular extrasystoles;
- bradycardia (slow heart rate);
- upset stomach;
- lightheadedness or dizziness;
- vision changes;
- loss of appetite;
- unusual weight gain;
- swelling of the feet;
- upset stomach;
Occasionally, high levels of this medicine can cause abnormal heart rhythms which could make the patient experience blackouts or palpitations as well as neuropsychiatric complications (such as – sleep disturbances and confusion), eosinophilia (an unusual increase in peripheral blood eosinophilic leukocytes), gynecomastia, and exanthema.
You should not use this medication if you have ventricular fibrillation (a heart rhythm disorder of the lower chambers of the heart or ventricles, which occurs when the heart beats with rapid electrical impulses).
This medicine can also be prescribed for a child to treat heart problems. However, it may have the following side effects:
- a slower-than-normal heart rate;
This drug should be avoided by pregnant women because the unborn child absorbs it in utero.
Digitalis vs Digoxin – Differences
Digitalis drugs are available only with a doctor’s prescription. They are usually sold in capsule, tablet, injectable, and liquid forms. Commonly used digitalis drugs include – digoxin (Lanoxin) and digitoxin (Crystodigin). All have many benefits for the cardiovascular system, but also side effects, especially for people with potassium and magnesium deficiency.