Digitalis is a genus of herbaceous plants known as foxglove. This word is also used to describe a drug preparation made up of dried foxglove leaves, which contain substances said to help stimulate the heart. These substances work by blocking certain proteins and altering nervous system signaling to increase the force of heartbeats and regulate abnormal rhythms.
This preparation is thought to work in two ways. First, digitalis works to slow the heart muscle by blocking an enzyme that serves to control the flow of potassium and sodium in and out of the cells of the heart. When this occurs, calcium is allowed to build within the cells, which tells the heart to contract.
The second way that digitalis works is through the nervous system. When this medication enters the body, it signals the nervous system to lower the heart rate and slow down the speed in which electrical signals are transmitted through the heart. Thus, the heart may then be given ample time to fill up with blood.
Although these actions are considered two of the most vital, digitalis may help the heart in other ways. For instance, this medication continues working with the nervous system to help stop the production of kidney hormones. When this occurs, blood vessels are allowed to relax, which can help to take stress off the heart.
Primarily used to treat patients with congestive heart failure and cardiac arrhythmia, digitalis contains substances known as glycosides. Glycosides are organic substances that contain non-sugar and sugar components; in this case, the sugar component is glucose. In most digitalis preparations, the main glycoside is known as digoxin.
When taken in small doses, digoxin is thought to help increase the activity of most muscle tissues, but is especially helpful to the heart and arterioles. One of its main beneficial effects is on blood circulation. When this substance enters the body, it is said to help contract the arteries and heart, raising blood pressure and forcing blood to circulate through the body. It may also help lower pulse rate, which will usually result in regulating an irregular pulse.
These preparations are usually started in small doses to help prevent toxicity. The process can take 12 or more hours to become effective. Additionally, some patients may not notice a drastic change in symptoms for several weeks after starting this medication.