Caffein


Categories: Uncategorized
Sources: Disturbances Of The Heart

Caffein can irritate the heart and cause irregularity and

tachycardia, especially in certain persons. In fact, some can never

take a single cup of coffee without having an attack of palpitation,

and many times when coffee and tea have been unsuspected by the

patient as the cause of cardiac irritability, their removal from the

diet has stopped the symptoms, and the heart has at once acted

normally.



Caffein is a stimulant and tonic to the heart, increasing its

rapidity and the strength of the contractions. It is also a cerebral

stimulant, one of the most active that we possess among the drugs.

It increases the blood pressure, principally by stimulating the

vasomotor center and by increasing the heart strength. It acts as a

diuretic, not only by increasing the circulatory force and blood

pressure, but also by acting directly on the kidney. This action on

the kidney contraindicates the use of caffein in any form, except in

rare instances, when there is acute or chronic nephritis. The

increased blood pressure caused by caffein also contraindicates its

use when there is hypertension. Caffein first accelerates the heart

and later may slow it and strengthen it; but if the dose is large or

too frequently repeated, the apex of the heart ceases to relax

properly and there is an interference with the contraction of the

ventricles, the heart muscle becomes irritable, and a tachycardia

may develop.



Therefore when a heart has serious lesions, whether of the

myocardium or of the valves, with compensation only sufficient, the

action of caffein in any form is contraindicated. The fact that it

raises the blood pressure, thus increasing the force against which

the heart must act, and that it irritates the heart muscle to more

sturdy or irregular contraction, indicates that a patient with a

heart lesion or with a nervously irritable heart should never drink

tea and coffee or take caffein in any beverage.



Many patients cannot sleep for many hours after they have taken

coffee or tea, as the cerebral stimulation of caffein is projected

for hours after its ingestion. Caffein does not absorb so quickly

and therefore does not act so quickly when taken in the form of tea

and coffee as it does when taken as the drug or as a beverage which

contains the alkaloid. Persons who are nervously irritable, excited

and overstimulated cerebrally, with or without high blood pressure,

should not take this cerebral and nervous excitant. This is true in

early childhood and in youth, and continues true as age advances, in

most persons. It is a crime to present caffein as a soda fountain

beverage to children and young persons when the excitement of the

age is such as already to overstimulate all nervous systems and all

hearts.



A considerable majority of persons over 40 learn that they cannot

drink tea or coffee with their evening meal without finding it

difficult to sleep. Such patients, of course, should omit this

stimulant. Some patients have already recognized this fact and its

cause; others must be told. The majority of adults are probably no

worse and may be distinctly benefited by the morning cup of coffee

and the noon coffee or tea, provided the amount taken is not large.

It seems to be a fact that the drinking of coffee is on the

increase, especially as to frequency. Certainly the five o'clock

tea, with women, is on the increase, and we must deal with one more

cerebral and nervous excitant in our consideration of what we shall

do to slow this rapid age.





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