2. Foxglove (digitalis purpurea) Flashcards
1500-1700 what was the main cause of death
- tuberculosis and other infectious diseases was dropsy, (an accumulation of bodily fluids (edema) in the body cavity and limbs that results in grotesque swelling
- these symptoms are indicative of a damaged, weakened heart; blood returns to the heart at very low pressure, resulting in fluids leaking from capillaries into surrounding tissues
- the problem is exacerbated by compromised kidney efficiency brought about by a weakened heart.
- the result is painful swelling of the body, increased stress on the heart, and (if left untreated) congestive heart failure
a traditional decoction containing foxglove and other plants was used in European folk medicine to treat the symptoms of …
dropsy
(for many centuries)
(this was spread by word of mouth)
european written herbals of the time recognized foxglove only as ..
a poisonous, not a medicinal, plant
william withering (1741-1799)
- studied medicine at edinburg, he was interested in surgery and anatomy.
- not initially fond of botany.
- wrote first complete english-language book on plants of the British isles (botanical arrangement of all the vegetables naturally growing in great Britain,1776) and became a famous medical botanist
- worked many years examining the effect of foxglove extracts on the heart, and was the first physician to develop a systematic regimen of experimental medical treatment
- administered standardized, controlled doses of dried foxglove leaves to 163 patients
a female herbalist in Stropshire, England cured a patient suffering from ..
dropsy using a herbal decoction containing foxglove leaves.
-the decoction included extracts from a number of plant species, but somehow withering realized that the active principle was from foxglove
withering published his findings in 1785
an account of the foxglove and some of its medical uses
- is research is an early example of a systematic experimental approach to elucidating the virtues and chemical properties of medicinal plant products
- withering also pioneered the formal development of a medical remedy through careful observation of its pharmacological effect on patients
the cardiotonic activity of foxglove is attributable to a group of closely related cardiac glycosides, particularly…
digoxin and digitoxin
digoxin and digitoxin
complex secondary products that even today are obtained from plant material
natural sourced cardiac glycosides remain critically important in modern western medicine for treating …
heart and circulatory system, which are among the leading causes of death in contemporary society
cardiac glycosides from foxglove are used to treat…
congestive heart failure brought on by hypertension and arteriosclerosis, and to restore and maintain normal heart rhythm.
-they exert their effect by increasing the contractibility and improving the tone of heart muscle, reducing but strengthening the heartbeat, slowing wildly beating ventricles to normal levels, and generally improving heart action (which in turn increases renal secretion, thereby reducing edema)
Digoxin
-remains the most widely prescribed cardiotonic drug in north american and Europe; it is used by over three million patients in the US alone
a number of other digitalis drugs ( including semi-synthetics) are also prescribed, included …
digitoxin, lanatoside C, acetyldigitoxin, and deslanoside
Recent research indicates that whole leaf extracts …
which include more than thirty related compounds
-may be more effective than any single isolated cardiac glycoside.
digitalis drug
- dosage varies among patients and must be determined and administered carefully, since the prescribed effective does may be as high as 70% of a lethal dose.
- digitalis drugs are extremely effective, but provide only temporary relief and must be taken regularly over a lifetime.
there are a number of serious and adverse side effects associated with regular use of digitalis drugs,
including nausea, excessive salivation, headache and fatigue
