Aspirin is one of the wonder drug in the field of cardio-vascular disease. It is the most commonly prescribed drug among heart attack and stroke patients. Aspirin is known as a salicylate and a nonsteroidal anti-inflammatory drug (NSAID). It works by blocking a certain natural substance in body to reduce inflammation. Among heart and stroke patients, it is used as ‘blood thinner’. Since the ancient times of its discovery, Aspirin is commonly used as a pain reliever for minor aches and pains and to reduce fever.
History of Aspirin
The history of aspirin (acetylsalicylic acid) goes back to late 19th century. Its synthesis and manufacture was in 1899. Before that, salicylic acid had been used medicinally since antiquity. Hippocrates referred to their use of salicylic tea to reduce fevers around 400 BC, and were part of the pharmacopoeia of Western medicine in classical antiquity and the Middle Ages. Willow bark extract became recognized for its specific effects on fever, pain and inflammation in the mid-eighteenth century. By the nineteenth century pharmacists were experimenting with and prescribing a variety of chemicals related to salicin, the active component of willow extract. The discovery of aspirin is customarily said to have resulted from Felix Hoffmann's rheumatic father encouraging his son to produce a medicine devoid of the unpleasant effects of sodium salicylate. Hoffmann, a chemist in the pharmaceutical laboratory of the German dye manufacturer Friedrich Bayer & Co in Elberfeld, consulted the chemical literature and came across the synthesis of acetylsalicylic acid and then prepared the first sample of pure acetylsalicylic acid on 10 August 1897. This was marketed in 1899 under the registered trademark of Aspirin. This account of the discovery first appeared in 1934 as a footnote in a history of chemical engineering written by Albrecht Schmidt, a chemist who had recently retired from IG Farbenindustrie—the organisation into which F Bayer & Co had been incorporated in 1925. Aspirin's effects on blood clotting (as an antiplatelet agent) were first noticed in 1950 by Lawrence Craven.
Heart attacks and strokes
Aspirin is an important part of the treatment of those who have had a heart attack or brain attack (stroke). For people who have already had a heart attack or stroke, taking aspirin daily for two years prevented 1 in 50 from having a cardiovascular problem (heart attack, stroke, or death), but also caused non-fatal bleeding problems to occur in 1 of 400 people. In those with no previous history of heart disease, aspirin decreases the risk of a non-fatal myocardial infarction but increases the risk of bleeding and does not change the overall risk of death. Specifically over 5 years it decreased the risk of a cardiovascular event by 1 in 265 and increased the risk of bleeding by 1 in 210. Aspirin appears to offer little benefit to those at lower risk of heart attack or stroke—for instance, those without a history of these events or with pre-existing disease. Some studies recommend aspirin on a case-by-case basis, while others have suggested the risks of other events, such as gastrointestinal bleeding, were enough to outweigh any potential benefit, and recommended against using aspirin for primary prevention entirely. After angioplasty, such as the placement of a coronary artery stent, aspirin to be taken indefinitely. Frequently, aspirin is combined with another blood thinning drug, such as Clopidogrel, Prasugrel, or Ticagrelor to prevent blood clots. This is called dual antiplatelet therapy (DAPT). Especially for those who had a major heart attack, or those who underwent an angioplasty with drug coated stents, to be taken this dual antiplatelet therapy (a combination of two blood thinners, in which one is always Ecospirin) for minimum one year. Of course this combination therapy is high risk for bleeding from any site, the physician will always compare the risk with benefit of such therapy in individual patient. There is no hard and fast rule here!!. If the bleeding risk is high, definitely the doctor will reduce the dose or number of blood thinning drugs. But if the bleeding risk is low, and the risk of blood clotting and subsequent consequences like recurrence of heart attack or blood clot formation in the placed stent is high, the doctor will think in favor of continuing full dose blood thinners. Here is the importance of regular follow-up with your family physician or cardiologist. He can closely watch for any evidence of frank or occult bleed. Following up with serial measurement of Hemoglobin will help your doctor to easily identify any fall in hemoglobin or chronic minor blood loss.
Use of Aspirin other than for heart attack and stroke
Nowadays one could do without aspirin as an analgesic and an anti-inflammatory since good alternatives are available. Aspirin is similarly efficient as paracetamol on trivial acute pain (e.g. headaches, dental pain, or colds). However, it is also used for chronic states of pain, e.g. for cancer patients and (in high doses) for rheumatic fever. For other rheumatic diseases (chronic polyarthritis, osteoarthritis, etc.) and for dysmenorrhea aspirin is not as efficient or not as well tolerated as other prostaglandin synthesis inhibitors such as ibuprofen. Rheumatic arthritis is the only arthritis, in which Aspirin is preferred over other drugs for treatment. In gynaecology practice, it is commonly used in pregnancy induced hypertension and recurrent pregnancy loss. In such cases it is used to prevent placental insufficiency. Basically here also, the antiplatelet action is utilized and Aspirin will prevent blood clot formation in small vessels of placenta. Similarly children with Kawasaki's disease initially receive high and later low aspirin doses. Kawasaki disease is a rare type of fever syndrome which is characterized by abnormally dilated coronary arteries. Other important use of this drug is in field of peripheral vascular disease (Occlusion of blood vessels of limbs). Antiplatelet action of Aspirin is utilized in the treatment of limb ischemia. The drug is hitherto unequalled as a platelet inhibitor and the number of significant indications in its favor has continuously grown in the last years.
Aspirin- How it works in the body?
Aspirin is quickly absorbed from our stomach and reaches a peak blood level in 30 minutes. Once it reaches liver it is actively metabolized to the molecule called salicylate. Salicylate level peak attain in 1 to 2 hours. The drug is almost always eliminated from the body by kidneys.
How to use Aspirin Tablet
If you are taking this medication for self-treatment, follow all directions on the product package. If you are uncertain about any of the information, consult your doctor or pharmacist. If your doctor has directed you to take this medication, take it exactly as prescribed. Take this medication by mouth. Drink a full glass of water (8 ounces/240 milliliters) with it unless your doctor tells you otherwise. Do not lie down for at least 10 minutes after you have taken this drug. If stomach upset occurs while you are taking this medication, you may take it with food or milk. Swallow enteric-coated tablets whole. Do not crush or chew enteric-coated tablets. Doing so can increase gastritis related side effects.. Do not crush or chew extended-release tablets or capsules. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split extended-release tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing. The dosage and length of treatment are based on your medical condition and response to treatment.
Aspirin: Adverse Reactions
When used as an analgesic aspirin often causes stomach pain, nausea, vomiting, and occult gastrointestinal blood loss. Dangerous gastrointestinal complications (bleeding, perforated ulcers) are relatively rare. The uncommon, so-called aspirin intolerance with potentially life-threatening bronchospasms occurs more frequently in persons with asthma, nasal polyps, or urticaria. Aspirin rarely causes hepatitis (if so then especially in persons with lupus erythematosus). The role of the salicylate in analgesic nephropathy (combination of analgesics!) is not clear. High doses cause ringing in the ear (tinnitus) and hearing loss. Doses of less than 100 mg/day very rarely cause complications.
Contraindications
Aspirin should not be taken by people who are allergic, and caution should be exercised in those with asthma or NSAID-precipitated bronchospasm. Owing to its effect on the stomach lining, people with peptic ulcers, or gastritis to be closely monitored for any bleed in stool or blood loss (anemia). Even if none of these conditions is present, the risk of stomach bleeding is still increased when aspirin is taken with alcohol or warfarin. People with hemophilia or other bleeding tendencies should not take aspirin or other salicylates. Use of aspirin during dengue fever is not recommended owing to increased bleeding tendency.
Gastrointestinal
Aspirin use has been shown to increase the risk of gastrointestinal bleeding. Although some enteric-coated formulations of aspirin are advertised as being "gentle to the stomach", enteric coating did not seem to reduce this risk. Combining aspirin with other NSAIDs has also been shown to further increase this risk. Using aspirin in combination with clopidogrel or warfarin also increases the risk of upper gastrointestinal bleeding.
Dr. Suneesh Kalliath
MD DNB DM DNB
Consultant Cardiologist
Kozhikode District Co-operative Hospital, Kozhikode