Digitalis /Dig·i·tal·is/ (dij″ĭ-tal´is) a genus of herbs. D. lana´ta yields digoxin and lanatoside, and the leaves of D. purpu´rea, the purple foxglove, furnish digitalis.
digitalis /dig·i·tal·is/ (dij″ĭ-tal´is)
Digitalis
digitalis
Digitalis [dij″ĭ-tal´is]
digitalis [dij″ĭ-tal´is]
digitalis
digitalis /dig·i·tal·is/ (dij″ĭ-tal´is)
1. the dried leaf of Digitalis purpurea; used as a cardiotonic agent.
2. the digitalis glycosides or cardiac glycosides, collectively.
dig·i·tal·is (d j -t l s)n. 1. A plant of the genus Digitalis, which includes the foxgloves, several species of which are a source of cardioactive steroid glycosides used in the treatment of certain heart diseases. 2. A pharmaceutical prepared from the seeds and dried leaves of the purple foxglove, Digitalis purpurea, and prescribed as a cardiac stimulant in the treatment of congestive heart failure and other disorders of the heart. |
Digitalis
A naturally occuring compound used in the preparation of the medication, digoxin, prescribed to increase the heart rate and strengthen the force of the heart's contractions.
digitalis
[dij′ital′is]
Etymology: L, digitus, finger or toe
a general term for cardiac glycoside. See also digitoxin, digoxin.
indications It is prescribed in the treatment of congestive heart failure and certain cardiac arrhythmias.
contraindications Ventricular fibrillation, ventricular tachycardia, or known hypersensitivity to this drug prohibits its use.
adverse effects The most serious reactions are cardiac arrhythmias that are more common with concomitant diuretics, disorientation, and visual distubances.
Digitalis [dij″ĭ-tal´is]
a genus of herbs. D. lana´ta yields digoxin and lanatoside and D. purpu´rea, the purple foxglove, has leaves that are a source of digitalis.
digitalis [dij″ĭ-tal´is]
dried leaf of Digitalis purpurea; a cardiac glycoside. All drugs prepared from this digitalis leaf are members of the same group and principles of administration are the same, although they vary according to speed of action and potency. Digitalis in its many forms is one of the most frequently prescribed drugs in the United States. It can be very effective in treatment of cardiac conditions, but its therapeutic range is narrow; a therapeutic dose is only about one third less than the dose that will induce toxicity. Moreover, physiologic changes due to age, electrolyte disturbances, renal impairment, metabolic disorders, and certain heart conditions can predispose a patient to digitalis toxicity. Other drugs can also alter the effects of digitalis and lead to toxicity.
Signs of Toxicity. Traditionally, nurses have been taught to count the patient's pulse or monitor the apical heartbeat for rate and rhythm before administering a digitalis preparation. A decreased pulse rate of 60 per minute or less is an indication that the drug should be temporarily discontinued. While this is the most typical sign of digitalis intoxication, there frequently are earlier symptoms that deserve attention. Some of the more common complaints expressed by patients who are in the early stages of toxicity are nausea, blurred vision, mental depression, disorientation, and malaise. Objective signs include vomiting, diarrhea, and confusion.
Drug Interactions. Unfortunately, most patients who take digitalis also have other drugs prescribed for the management of their illness. The risk of drug interactions and digitalis toxicity increases in proportion to the number of drugs being taken concurrently. One of the most common interactions is with a thiazide diuretic, which can enhance the effect of digitalis and can also lower potassium levels in the blood. Potassium decreases the likelihood of digitalis toxicity and so it is essential that hypokalemia be avoided. Since many patients who take digitalis are on restricted caloric and fluid intake, they cannot adequately replace lost potassium by eating enough potassium-rich foods and need a potassium supplement.
Patient Education. There is a danger of complacency about this drug because it is so familiar and so frequently prescribed for self-medication. Without unduly alarming the patient, it is imperative that the action of the drug and its potential for harm if it is not taken as prescribed and with caution are explained. The patient must be informed about the interactions of digitalis with over-the-counter drugs such as antacids and cold remedies that contain ephedrine. The patient should know the signs and symptoms of digitalis toxicity and appreciate the importance of notifying the primary health care provider should any of these signs appear. If the patient does not know how to check the pulse for rate and rhythm, he or she will need to learn how and to learn why it is important to stop taking the drug and notify the physician should the pulse rate fall outside the normal range. There is so much that needs to be known in order to avoid the problems of toxicity inherent in the particular digitalis preparation that it is probably unrealistic to expect patients to remember all that they are told about taking the medication safely. Therefore it is best to give the patient the information in written form and go over the instructions with the patient and a member of the family in order to be sure that the instructions are understood.
Digitalis
a genus of herbs in the family Scrophulariaceae; contains digitalis-related (cardenolide) cardiac glycosides, e.g. digoxin, lanatoside. Includes D. lanata (woolly foxglove), D. purpurea (purple foxglove). Sources of commercial digitalis.
digitalis
dried leaf of Digitalis purpurea; used as a cardiotonic agent. All drugs prepared from this digitalis leaf are members of the same group and principles of administration are the same. The drugs vary according to speed of action and potency. Digitalis can be very effective in the treatment of various cardiac conditions, but its therapeutic range is very narrow; a therapeutic dose is only about one-third less than the dose that will induce toxicity. Toxicity is manifested by vomiting, diarrhea, cardiac irregularity and heart failure.
digitalis glycosides
digitoxin, digoxin.
digitalis
Cardiology A cardiac glycoside first found in foxglove, Digitalis purpurea, now of historic interest; the synthetic derivatives, digoxin and digitoxin are the most popular of the cardiac glycosides
Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content.
| ?Page tools | ||
|---|---|---|
|