You do not have to believe in Adam and Eve to recognize the
significance of an apple . the old saying “ an apple a day keeps the doctor
away “ has been changed to “ an aspirin a day keeps the doctor away” .
Hippocrates , 400 BC and Beyond
As early as BC 350 , Hipporcates tried to relieve the pain of his patients by
asking them to chew willow bark , a natural substance which contains salicylic
acid . in 1763 , Reverend stone of chipping Norton , England , showed the
benefit of willow bark for individuals with ague and fever . Today pain can be
relieved by aspirin , which also contains salicylic acid .
For More reading the rest of article please click READ MOREM>> !
Von Gerhardt 1853
The use of salicylic acid ,
however did not become common until 1853 when Von Gerhardt of Bayer developed
aspirin and in 1899 , Felix Hoffman , a Bayer Chemist , used aspirin to treat
his father’s rheumatism .
Lawerence Craven 1953
The firs clinical trial of
aspirin in patients occurred from 1948 to 1956 when a general practitioner ,
Lawrence Craven , treated 1500 relatively healthy ,overweight ,sedentary men
between the ages of40 and 65 . The result of the study reported in the
Mississippi Vallery Journal concluded that one aspirin a day was sufficient ,
because none of Lawrence Crawen’s 1500 patients experienced a heart attack over the
five-years course of treatment . This small study , however , did not influence
physicians to prescribe aspirin to patients for heart problem .
John Vane , 1971
Credit for influencing
physicians to prescribe aspirin for heart problems must be given to John
Vane . He showed that aspirin blocks the action of special substances in the
body called prostaglandins . This action prevents blood platelets from clumping
together to produce a clot .
Thus , aspirin is referred to as an antiplatelet agent that is a
mild blood thinner . A study in the UK by Elwood et al . found aspirin to be of
no significant benefit when taken for a few years following a heart attack .
unfortunately , patients were enlisted at various durations after their heart
attacks ( from 3 to 6 months ) . Aspirin was not administered immediately
following the myocardial infarction. This flaw in methodology and controversies
delayed the use of aspirin for the next 10 years .
Lewis et al. 1983
The timely 1983 study by Lewis et al , in the United States
heralded a new era , and aspirin became widely known as a life-saving drug .
This study showed that one Alka-Seltzer containing 325 mg of acetulsalicylic
acid , given to patients with severe angina ( heart pains , unstable angina ) ,
caused a 49% reduction in nonfatal and fatal heart attacks . A Canadian study
testing aspirin , sulfinpyrazone , or both in unstable angina confirmed Lewis’
observation that aspirin given immediately to patients who presented to the emergency
room with severe chest pain or unstable angina prevented serious event .
ISIS-2 1988
This Landmark study is the first to show the remarkable benefits of
aspirin when given immediately following the onset of chest pain caused by
myocardial infarction .
The second International Study of Infarct Survival (ISIS-2) , a study mounted in
the UK , confirmed a marked increase in survival in a large group of patients
given 160mg of plain aspirin ( non-coated) within 6hours of the onset of chest
pain causing the heart attack. In that study , aspirin greatly improve the lifesaving
effects of streptokinase , a drug used dissolve
clots soon after the occurrence of a heart attack .
Primary Prevention , 1988
Finally in 1988 a trial with 22,071 male U.S. physicians aged 40-84
given 325mg of aspirin on alternate days for five years demonstrated that
aspirin use resulted in a 44% reduction in the risk of non-fatal MI . This
Trial endorsed the use of small-dose coated aspirin preparations in normal individuals
deemed at risk for coronary artery disease and its complications .
Swedish Trial 1992
The Swedish angina pectoris aspirin trial studied 2035 patients
with chronic stable angina without infarction . Aspirin 75mg reduce the
occurrence of infarction and sudden death by 34% in the treated patients versus
placebo .
Life Saving Measures
Based on the proven benefits observed in ISIS-2 , taking aspirin is
a lifesaving measure when taken within a few hours of chest pain or symptoms
resolving from a developing a heart attack .
The dose should be one plain 325 mg tablet of aspirin chewed an swallowed
or preferably, 2-4 chewable aspirins (80mg each, a dose of 160-320mg ) .
It is important for the public at large to recognize that chewable
aspirin taken immediately during the pain of heart attack can either prevent a
heart attack or prevent death in a significant number of individuals . Most
important , the nitroglycerine table or spray use under the tongue commonly
prescribed and used by patients is of no value in preventing a heart attack or
death when the process of MI has begun . After a heart attack has been stabilized
, an enteric coated preparation of aspirin is then continued for several years
and sometimes indefinitely .
Prevention in normal INDIVIDUALS
AT risk
Men over age 45 or women over age 60 with risk factors including :
family history of heart attack before age 60 ; high cholesterol levels greater
than 5.5 mmol/lit or LDL cholesterol greater than 160mg /dl ( 4mmol) ;
hypertension , or diabetes are at risk for the development of atherosclerotic
coronary artery disease and its complications . The dose of one enteric-coatied
80 to 81 mg aspirin daily is recommended
for these patients .
A study reported ( N.Engl.J.Med.April 2005) indicated that in
healthy women age 45-64 with one or no risk factors , low dose aspirin ( 100mg
alternate day ) did not significantly reduce risk of heart attack but prevented
non-fatal stroke risk . I must point out that there is no gender difference in
the efficacy of aspirin as some may believe . In women age 35-55 heart attacks
are rare compare to men . the result of the study is not surprising ,
therefore, because one cannot prevent heart attacks if they do not occur in
that age group . The study was underpowered. the reason why strokes occur in women
45-55 when heart attacks are uncommon at this age has as yet , not been
clarified .
Most important , in the above study aspirin did not prevent fatal
stroke rates . The pathophysiologic mechanism causing fatal stroke and heart
attack is similar . an athermatous plaque undergoes erosion of rupture
liberating a porridge like material that is intensely thrombogenic and the
thrombus cannot be ameliorated by aspirin or other antiplatelet agents that do
not affect the culprit thrombotic factors . in the study transient ischemic attacks
(TIAs) were significantly reduced , however . this finding is not surprising
because TIAs are caused by platelet emboli and platelet thrombi have been shown
in randomized clinical trials to be significantly prevented by antiplatelet
agents such as Plavix or the combination of aspirin and dipyrimadole . A small
stroke represents the continuation process of a transient ischemic attack some
of which can be prevented therefore by aspirin or other antiplatelet agent .
Women ages 45-64 who have more than one cardiovascular risk factor should be benefit
significantly in the prevention of nonfatal strokes and TIAs with the use of small
dose aspirin 75 – 81 mg enteric coated daily . those with two or more risk
factors may benefit from risk of heart attack . the above study use 100mg
alternate day and this may not be an adequate dose to prevent non-fatal heart
attacks .
No comments:
Post a Comment