Aspirin (acetylsalicylic acid). What Acetylic Acid Helps for Aspirin or Acetylsalicylic Acid

Emphasis on the presence or absence of contraindications. Both drugs have, which you need to familiarize yourself with before starting. And if regular aspirin is not recommended for a long time due to a negative effect on the stomach, cardio aspirin can be drunk for a long time. It is even possible to take such a drug for life for prophylactic purposes, of course, in compliance with the dosage.

Difference between regular and cardio aspirin

Most often, traditional aspirin is prescribed to relieve a number of symptoms: headache, fever, inflammation. Whereas aspirin cardio is used to prevent and treat cardiovascular disease. It can be taken for migraine, thrombosis in high-risk patients, embolism, unstable angina pectoris.

The acid resistance of cardio aspirin minimizes side effects even with prolonged use of the drug.

The difference is the fact that cardio aspirin has a special shell - enteric. With its help, the medicinal product does not harm the human stomach, it dissolves and is absorbed in the intestine. Therefore, aspirin cardio is also prescribed in the presence of diseases of the gastrointestinal tract.

The antiplatelet effect of acetylsalicylic acid is observed when taking aspirin in small doses - 100 mg, which is why aspirin is recommended to reduce the risk of heart attack and stroke. It is able to thin the blood and cardio, and simple aspirin, it is more important to take into account the dosage of the drugs.

Should I choose cardio or simple aspirin?

If you plan on taking aspirin to keep your heart healthy, you should opt for cardio aspirin as it will not harm your stomach. Simple aspirin will help more in the treatment of colds, fever and pain, and fever.

A special cardiac form of acetylsalicylic acid has been proven to be safe and effective. It should be noted that cardio aspirin comes in two dosage forms - 100 and 300 mg. The first is used for prophylactic purposes, and the second will become an indispensable choice for patients who have suffered a heart attack or stroke in critical situations. And if earlier it was thought that cardiological aspirin is ideal for men, modern research has proven lasting positive results in women.

Cardio aspirin is recommended for patients with diabetes mellitus and arterial hypertension. You need to take only one tablet a day on an empty stomach with water.

Of course, there is also a difference in the price of the two drugs. For ordinary aspirin, it is about 10 rubles, while for its cardiological counterpart - about 100 rubles. and higher.

Both drugs have similar effects on the human body. These medications are interchangeable.

What is the difference and similarity between Acetylsalicylic acid and Aspirin?

There is no difference between the 2 drugs. However, they have a lot in common. These medicines are taken to eliminate fever, inflammation and pain in various diseases. Most often, drugs are prescribed for the flu and colds, as well as discomfort in muscles and joints. These drugs affect platelet aggregation, resulting in a decrease in blood clotting ability. This property allows prescribing drugs in the presence of cardiovascular diseases associated with the formation of blood clots.

As anesthetic and antipyretic drugs, such medicines are used for inflammatory and infectious pathologies of the urinary organs, as well as sore throat and pneumonia. The effectiveness of these funds in heart disease has been proven by their positive effect on patients with high blood viscosity. Medicines are used not only for therapy, but also for the prevention of blood clots.

Anti-inflammatory properties are due to inhibition of the activity of the enzyme arachidonic acid. Topical medications are used to treat acne.

Indications for use:

• hangover;
• increased body temperature;
• pain syndrome.

Both medicines have the same composition. Medicines are not prescribed for pregnant women, as well as during lactation. Additional contraindications:

• ulcerative lesions of the stomach and duodenum due to the high risk of bleeding;
• asthma;
• hypersensitivity to acetylsalicylic acid;
• decreased blood clotting.

Medicines should not be taken by children under 15 years of age. The drugs should be taken only after meals to reduce the risk of inflammatory stomach diseases. Acetylsalicylic acid has a negative effect on the mucous membranes of the gastrointestinal tract. Large doses of these drugs can provoke bleeding and dyspeptic disorders.

Side effects:

• stomach pain;
• nausea;
• heartburn;
• vomiting blood;
• dizziness;
• allergic reaction;
• bleeding from the gastrointestinal tract.

An overdose of NSAIDs is dangerous, therefore, with an increase in the dose and the occurrence of confusion, tinnitus and dizziness, it is imperative to call an ambulance.

In every family, a medicine such as acetylsalicylic acid is necessarily present in the first aid kit. But every second person is interested in the following question: "Acetylsalicylic acid is" Aspirin "or not?" This is what will be discussed in our article, and we will also talk about the properties and use of this drug.

A bit of history

Acetylsalicylic acid was first discovered at the end of the 19th century by the young chemist Felix Hoffman, who at that time worked for Bayer. He really wanted to develop a remedy that would help his father relieve joint pain. The idea of \u200b\u200bwhere to look for the required composition was suggested to him by his father's doctor. He prescribed sodium salicylate to his patient, but the patient could not take it, as it greatly irritated the gastric mucosa.

Two years later, a drug such as Aspirin was patented in Berlin, so acetylsalicylic acid is Aspirin. This is an abbreviated name: the prefix "a" is an acetyl group that was attached to salicylic acid, the root "spir" indicates spireic acid (this type of acid is present in the form of an ester in plants, one of them is spirea), and the ending "in" in those days, they were often used in the names of medicines.

"Aspirin": chemical composition

It turns out that acetylsalicylic acid is "Aspirin", and its molecule contains two active acids: salicylic and acetic. If you store the drug at room temperature, then at high humidity it quickly decomposes into two acidic compounds.

That is why acetic and salicylic acids are always present in the composition of "Aspirin"; after a short period of time, the main component becomes much less. The shelf life of the drug depends on this.

Taking a pill

After "Aspirin" enters the stomach, and then into the duodenum, the juice from the stomach does not act on it, since the acid dissolves best in an alkaline medium. After the duodenum, it is absorbed into the bloodstream, and only there it is reincarnated, salicylic acid is released. While the substance reaches the liver, the amount of acids decreases, but their water-soluble derivatives become much more.

And already passing through the vessels of the body, they reach the kidneys, from where they are excreted along with urine. At the exit from "Aspirin" there remains a scanty dose - 0.5%, and the remaining amount is metabolites. It is they who are that medicinal composition. I would also like to say that the drug has 4 therapeutic effects:

• Prevention of blood clots.
• Anti-inflammatory properties.
• Antipyretic action.
• Relieves pain syndrome.

Acetylsalicylic acid has a large area of \u200b\u200bapplication, the instruction contains detailed recommendations for use. It is imperative to read it or consult a doctor.

"Aspirin": application

We found out how acetylsalicylic acid works. From what she helps, let's figure it out further.

1. Used for pain.
2. At high temperatures.
3. With all sorts of inflammatory processes.
4. In the treatment and prevention of rheumatism.
5. For the prevention of thrombosis.
6. Prevention of stroke and heart attack.

An excellent drug is acetylsalicylic acid, the price for it will also delight everyone, because it is low and ranges from 4-100 rubles, depending on the manufacturer and dosage.

Aspirin: the fight against blood clots

Blood clots form in places of the blood vessel where there is any damage to the walls. In these places, the fibers are exposed, which hold the cells together. Blood platelets are retained on them, which secrete a substance that helps to enhance adhesion, and in such places the vessel narrows.

Most often, in a healthy body, thromboxane is opposed by another substance - prostacyclin, it does not allow platelets to stick together and, conversely, dilates blood vessels. At the time when the vessel is damaged, the balance between these two substances shifts, and prostacyclin simply stops being produced. Thromboxane is produced in excess and the platelet clump grows. Thus, the blood flows through the vessel every day more and more slowly. In the future, this can lead to a stroke or heart attack. If acetylsalicylic acid is constantly taken (the price of the drug, as already noted, is more than affordable), then everything changes dramatically.

The acids included in Aspirin prevent the rapid growth of thromboxane and help remove it from the body. Thus, the drug protects blood vessels from blood clots, but it costs at least 10 days to take the medicine, since only after this time the platelets restore their ability to stick together.

Acetylsalicylic acid as an antipyretic agent

Due to the fact that this drug has the ability to expand blood vessels, the heat released by the human body is removed much better - the temperature drops. Acetylsalicylic acid from temperature is considered the best drug. In addition, this drug also acts on the thermoregulatory centers of the brain, giving it a signal to lower the temperature.

It is undesirable to give this medicine as an antipyretic to children because of its strong irritant effect on the stomach.

Aspirin as an anti-inflammatory and pain reliever

This drug also interferes with the inflammatory processes of the body, it prevents the release of blood to the sites of inflammation, as well as those substances that cause pain. It has the ability to enhance the production of the hormone histamine, which dilates blood vessels and increases blood flow to the site of the inflammatory process. It also helps to strengthen the walls of small blood vessels. All this creates an anti-inflammatory and analgesic effect.

As we found out, acetylsalicylic acid is effective from temperature. However, this is not its only advantage. It is effective for all types of inflammation and pain in the human body. That is why this drug is most often found in home medicine kits.

"Aspirin" for children

Acetylsalicylic acid is prescribed for children at elevated temperatures, infectious and inflammatory diseases and with severe pain. It should be taken with caution by children under the age of 14. But for those who have reached the age of 14, you can take half a tablet (250 mg) in the morning and evening.

"Aspirin" is taken only after meals, and children should definitely grind the tablet well and drink plenty of water.

Contraindications

Acetylsalicylic acid (this is "Aspirin" as most people call it) can not only benefit the body, but also harm. It is considered a very aggressive agent.

The first thing you don't need to do is use an expired drug, as Aspirin can irritate the stomach lining, which will eventually lead to an ulcer. In addition, for those who have gastrointestinal diseases, the drug should be taken only as directed by the doctor and it is best to drink the medicine with milk. People with kidney and liver diseases should also take it with extreme caution.

It is not recommended for women to take the drug during pregnancy, as there is evidence that it can adversely affect the development of the fetus. Yes, and before childbirth, you should not use it, as this will lead to a weakening of contractions or may cause prolonged bleeding.

If you think that acetylsalicylic acid is completely harmless, the instructions say something completely different. She has a lot of contraindications and side effects. Before applying, you must weigh all the pros and cons.

Conclusion

So, let's summarize. What does acetylsalicylic acid help from? This drug helps against fever, blood clots, it is an excellent anti-inflammatory and pain reliever.

Even despite the fact that the drug has serious contraindications for use, it is promised a bright future. Currently, most scientists are looking for such supplements that could reduce the detrimental effect of the drug on individual organs. There is also an opinion that other drugs will not be able to displace Aspirin, but, on the contrary, it will have new areas of application.

Aspirin (acetylsalicylic acid) is one of the most famous remedies for fever. But the use of this medication is more extensive - it even helps against thrombosis and other cardiovascular diseases.

Acetylsalicylic acid - description

Acetyl (acetylsalicylic) acid - a substance of the NSAID group, salicylic ester of acetic acid. The drug is included in the list of vital, long-known, well-studied. It has a number of positive effects on the body, the most important of which are antiaggregate, antipyretic, and analgesic. The drug was first patented by Bayer under the brand name Aspirin.

The acid was isolated in 1838 from white willow bark - a famous folk remedy for fever, headache. It was originally used to treat rheumatism, then gout. Since 1904, the drug has been sold in the form of tablets (initially it existed in the form of a powder). Tablets of 0.1, 0.25, 0.5 g have a round shape, in the middle - with a horizontal stripe.

Additional components:

• lemon acid;
• potato starch.

The drug is produced by almost all well-known pharmaceutical companies, for example, "Dalkhimpharm", "Tatkhimfarmpreparaty", "Novasil".

Action on the body

This drug works as follows - inhibits the synthesis of prostaglandins and inhibits the production of thromboxanes. The substance acts by inhibiting cyclooxygenase, and this enzyme takes part in the creation prostaglandins (inflammatory mediators) and thromboxanes... Acetylsalicylic acid affects the inflammatory process that occurs in the tissues. Also the medicine:

• reduces capillary permeability;
• reduces the activity of hyaluronidase;
• limits the formation of ATP, preventing the provision of inflammatory phenomena with energy.

The drug, when taken internally, reduces fever - normalizes the temperature, which is associated with its effect on the thermoregulation centers of the hypothalamus.

Also, acid has an analgesic effect by reducing the production of bradycardin and affecting pain centers.

The most important ability of Aspirin is that it thins the blood - therefore, the drug is widely used against the formation of blood clots.

All these mechanisms of action provide the drug with analgesic, antipyretic, anti-inflammatory, anti-febrile, anti-rheumatic action. The acid also reduces intracranial pressure and headaches.

Indications for use

You can drink medicine for completely different pathologies related to different areas of medicine. The best known treatment with Aspirin in acute conditions accompanied by pain, fever, inflammation:

Also, acetylic acid helps with pericarditis - inflammation in the serous membrane of the heart, with dressler's syndrome (when pericarditis develops in combination with pneumonia, pleurisy). For blood thinning, Aspirin is indicated for many people over 55 who have a risk of heart attack, stroke. It should also be taken for long courses with ischemic heart disease, an already occurred stroke, heart attack.

Other possible indications for which Aspirin should be given:

• prevention of thromboembolism;
• heart defects;
• atrial fibrillation;
• acute thrombophlebitis;
• lung infarction;
• TELA.

With the help of small doses of the drug, they form a tolerance to NSAIDs in the presence of the "aspirin triad" (nasal polyposis, bronchial asthma, allergy to acetyl acid).

Instructions for use

According to the instructions, acetylic acid must be taken orally, at the very beginning of a meal, or at the end of a meal. This will help prevent a common side effect - the appearance of erosions, irritations on the wall of the stomach, small intestine.

Experts advise drinking Aspirin with milk or alkaline mineral water without gas - this will reduce the irritating effect of the acid on the digestive system.

The dosage is different, it depends on the age, type of disease. Drinking is usually enough 0.5 g 2-4 times / day (the number is for adults). Course duration up to 12 days, more often - 3-5 days.

Features of therapy in some cases are as follows:

1. For the prevention of heart problems, blood vessels, dangerous thrombosis. They drink half a pill in the morning (once a day). The course is up to 2 months without interruption. At the same time, blood clotting and platelet count tests are done every 2 weeks.
2. With rheumatism. Aspirin is taken at 5-8 g / day for adults, for children, 100 mg for each kg of weight / day. The specified dose is divided into 5 doses. After a week of such pulse therapy, the dosage is reduced on an individual basis, the total duration is 6 weeks. Cancellation is done gradually.
3. For headaches. You can drink 2 tablets for an adult, for a child - 10 mg / kg of body weight per dose.
4. Children from 5 years old are usually given 0.25 g of Aspirin, from 2 years old - 0.1 g each, from a year - 0.05 g each.

The drug is widely used in cosmetology. For example, there is such a recipe for an acne face mask. You need to grind 6 tablets, add lemon juice or honey to the state of gruel. Apply only to inflamed skin areas, leave for 15 minutes, rinse.

Side effects and prohibitions

It is strictly forbidden to give acetylic acid to children if they develop a viral infection. In this case, the risk of Reye's syndrome is high, since the drug acts on the structures of the liver, brain, which are attacked by the virus. There are other contraindications to therapy:

In many cases, long-term therapy causes a number of "side effects". These are nosebleeds, uterine, intestinal, diarrhea, dyspepsia, nausea, vomiting, poor appetite, weakness, dizziness. Short-term visual impairment is possible. The amount of hemoglobin and platelets in the blood can change. With a tendency to kidney disease, some people develop renal failure. From allergic reactions, bronchospasm, asthma, rash, anaphylaxis are possible.

During pregnancy, it is strictly forbidden to drink the drug in 1.3 trimesters, in the 2nd trimester, in agreement with the doctor, a one-time admission is allowed. In the initial stages of lactation, the drug increases the risk of developing fetal anomalies, heart defects, cleft palate. In the last stages there is a danger of closing the fetal aortic duct ahead of time. If in the 2nd trimester the expectant mother is forced to take the drug for a long time, she should be regularly tested.

Systematic (IUPAC) name: 2-acetoxybenzoic acid
Legal status: dispensed by pharmacist only (S2) (Australia); allowed for free sale (UK); available over the counter (USA).
In Australia, the drug is Schedule 2, with the exception of intravenous use (in which case the drug is on Schedule 4), and is used in veterinary medicine (Schedule 5/6).
Application: most often orally, also rectally; lysine acetylsalicylate can be used intravenously or intramuscularly
Bioavailability: 80-100%
Protein binding: 80-90%
Metabolism: hepatic, (CYP2C19 and possibly CYP3A), some of it is hydrolyzed into salicylate in the walls of the esophagus.
Half-life: dose dependent; 2-3 hours when taking small doses, and up to 15-30 hours when taking large doses.
Excretion: urine (80-100%), sweat, saliva, feces
Synonyms: 2-acetoxybenzoic acid; acetylsalicylate;
acetylsalicylic acid; O-acetylsalicylic acid
Formula: C9H8O4
Mol. mass: 180.157 g / mol
Density: 1.40 g / cm³
Melting point: 136 ° C (277 ° F)
Boiling point: 140 ° C (284 ° F) (decomposes)
Solubility in water: 3 mg / ml (20 ° C)
Aspirin (acetylsalicylic acid) is a salicylate drug used as an analgesic for mild pain relief, and as an antipyretic and anti-inflammatory agent. Aspirin is also an antiplatelet agent and inhibits the production of thromboxane, which normally binds platelet molecules and creates a patch over damaged blood vessel walls. Because this patch can also grow and block blood flow, aspirin is also used to prevent heart attacks, stroke, and blood clots. Low-dose aspirin is used immediately after a heart attack to reduce the risk of a second attack or death of heart tissue. Aspirin can be effective in preventing certain cancers, especially colon and rectal cancers. The main side effects of aspirin are stomach ulcers, stomach bleeding, and tinnitus (especially when taken in high doses). Aspirin is not recommended for children and adolescents with flu-like symptoms or viral illnesses due to the risk of Reye's syndrome. Aspirin belongs to a group of drugs called "non-steroidal anti-inflammatory drugs" (NSAIDs), but has a different mechanism of action from most other NSAIDs. Although aspirin and drugs with a similar structure act similarly to other NSAIDs (exhibiting antipyretic, anti-inflammatory, analgesic effects) and inhibit the same cyclooxygenase (COX) enzyme, aspirin differs from them in that it acts irreversibly and, unlike other drugs, acts more on COX-1 than COX-2.

The active ingredient in aspirin was first discovered in willow bark in 1763 by Edward Stone of Wadham College, Oxford. The doctor discovered salicylic acid, the active metabolite of aspirin. Aspirin was first synthesized by Felix Hoffmann, a chemist at the German company Bayer, in 1897. Aspirin is one of the most widely used medicines in the world. Approximately 40,000 tonnes of aspirin are consumed worldwide every year. In countries where aspirin is a registered trademark of Bayer, the generic acetylsalicylic acid is sold. The drug is included in the list of essential medicines of the World Health Organization.

The use of aspirin in medicine

Aspirin is used to treat a variety of symptoms, including fever, pain, rheumatic fever, and inflammatory conditions such as rheumatoid arthritis, pericarditis, and Kawasaki disease. In low doses, aspirin is used to reduce the risk of death from heart attack or stroke. There is evidence that aspirin can be used to treat bowel cancer, but its mechanism of action has not been proven.

Aspirin-analgesic

Aspirin is an effective analgesic for the treatment of acute pain, but is inferior to ibuprofen in that the latter is associated with a lower risk of gastric bleeding. Aspirin is not effective for pain caused by muscle cramps, flatulence, bloating, or severe skin damage. As with other NSAIDs, the effectiveness of aspirin is increased when taken in combination with. Effervescent aspirin tablets such as Alkoselzer or Blowfish relieve pain faster than conventional tablets and are effective in treating migraines. Aspirin in the form of an ointment is used to treat certain types of neuropathic pain.

Aspirin and headache

Aspirin, alone or in combination formulas, is effective in treating some types of headaches. Aspirin may not be effective for treating secondary headaches (caused by other illnesses or injuries). The International Classification of Diseases Associated with Headaches distinguishes tension headache (the most common type of headache), migraine and cluster headaches among primary headaches. Aspirin or other over-the-counter analgesics are used to treat tension headache. Aspirin, especially as a component of the acetaminophen / aspirin / Excedrin Migraine formula, is considered an effective first-line treatment for migraines, and is comparable in effectiveness to low-dose sumatriptan. The drug is most effective in stopping migraines at the onset.

Aspirin and fever

Aspirin acts not only on pain, but also on fever through the prostaglandin system by irreversibly inhibiting COX. Although aspirin is widely approved for use in adults, many medical societies and regulatory agencies (including the American Academy of Family Therapists, the American Academy of Pediatrics, and the FDA) do not recommend the use of aspirin as a febrifuge for children. Aspirin may be associated with the risk of Reye's syndrome, a rare but often fatal illness associated with the use of aspirin or other salicylates in children with viral or bacterial infections. In 1986, the FDA ordered manufacturers to place a warning on the risks of aspirin use in children and adolescents on all aspirin labels.

Aspirin and heart attacks

The first studies of the effects of aspirin on the heart and heart attacks were carried out in the early 1970s by Professor Peter Slate, Professor Emeritus of Heart Medicine at the University of Oxford, who formed the Aspirin Research Society. In some cases, aspirin can be used to prevent heart attacks. At lower doses, aspirin is effective in preventing the development of existing cardiovascular diseases, as well as in reducing the risk of developing these diseases in individuals with a history of similar diseases. Aspirin is less effective for people with a low risk of heart attack, such as people who have never had a similar condition in the past. Some studies recommend that aspirin is taken on an ongoing basis, while others do not recommend such use due to side effects, such as stomach bleeding, which usually outweigh any potential benefits of the drug. When aspirin is used prophylactically, the phenomenon of aspirin resistance can be observed, manifested in a decrease in the effectiveness of the drug, which can lead to an increase in the risk of a heart attack. Some authors suggest testing resistance to aspirin or other antithrombotic drugs before starting treatment. Aspirin has also been proposed as a component of a drug for the treatment of cardiovascular diseases.

Post-surgical treatment

The US Agency for Health Research and Quality Guidelines recommends the long-term use of aspirin after a percutaneous coronary intervention procedure, such as coronary artery stent placement. Aspirin is often combined with adenosine diphosphate receptor inhibitors, such as clopidogrel, prasugrel, or ticagreol, to prevent blood clots (dual antiplatelet therapy). Recommendations for the use of aspirin in the United States and Europe differ somewhat regarding how long and for what reasons such combination therapy should be given after surgery. In the United States, dual antiplatelet therapy is recommended for a minimum of 12 months, and in Europe, 6–12 months after using a drug stent. However, the recommendations in both countries are consistent on the issue of indefinite use of aspirin after the completion of antiplatelet therapy.

Aspirin and cancer prevention

The effects of aspirin on cancer, especially colon cancer, have been studied extensively. Numerous meta-analyzes and reviews indicate that continued use of aspirin reduces the long-term risk of bowel cancer and mortality. However, no relationship was found between aspirin dose, duration of use, and various risk indicators, including mortality, disease progression, and risk of disease. Although most of the data on aspirin and the risk of bowel cancer comes from observational studies rather than randomized controlled trials, the available data from randomized trials indicate that long-term use of low-dose aspirin may be effective in preventing some types of colon cancer. In 2007, the US Preventive Service issued a directive on this issue, giving the use of aspirin to prevent colon cancer a “D” rating. The service also discourages doctors from using aspirin for this purpose.

Other uses of aspirin

Aspirin is used as first-line therapy for fever symptoms and joint pain in acute rheumatic fever. Treatment often lasts for one to two weeks, and the drug is rarely prescribed for long periods of time. Once the fever and pain are relieved, aspirin is no longer necessary, but it does not reduce the risk of heart complications or residual rheumatic heart disease. Naproxen is as effective as aspirin and is less toxic, however, due to limited clinical data, naproxen is only recommended as a second-line treatment. Aspirin is recommended for children only for Kawasaki disease and rheumatic fever, due to the lack of high-quality data on its effectiveness. At low doses, aspirin is moderately effective in preventing preeclampsia.

Aspirin resistance

In some people, aspirin is not as effective on platelets as in others. This effect is called "aspirin resistance" or insensitivity. One study showed that women are more prone to resistance than men. An aggregation study involving 2930 patients showed that 28% of patients develop aspirin resistance. A study of 100 Italian patients showed that, on the other hand, of 31% of aspirin-resistant patients, only 5% had actual resistance, while the rest had non-compliance (non-adherence to drug intake). Another study in 400 healthy volunteers showed that none of the patients showed actual resistance, but some showed "pseudo-resistance, reflecting delayed or reduced drug absorption."

Aspirin dosage

Adult aspirin tablets are manufactured in standard dosages that vary slightly from country to country, such as 300 mg in the UK and 325 mg in the US. Reduced dosages are also linked to existing standards such as 75 mg and 81 mg. The 81 mg tablets are conventionally referred to as the "child dose", although they are not recommended for use in children. The difference between 75 mg and 81 mg tablets is not of significant medical significance. Interestingly, in the United States, 325 mg tablets are equivalent to 5 grains of aspirin used up to the metric system used today. In general, for fever or arthritis, adults are advised to take aspirin 4 times a day. Historically, doses close to the maximum have been used to treat rheumatic fever. For the prevention of rheumatoid arthritis in individuals with present or suspected coronary artery disease, lower doses are recommended once daily. The US Prophylactic Service recommends the use of aspirin for the primary prevention of coronary heart disease in men aged 45–79 and women aged 55–79 only if the potential benefits (reducing the risk of myocardial infarction in men or stroke in women) outweigh the potential risk gastric damage. A study by the Women's Health Initiative showed that regular low-dose aspirin (75 or 81 mg) in women reduces the risk of death from cardiovascular disease by 25% and 14% - the risk of death from other causes. Low-dose aspirin use is also associated with a reduced risk of cardiovascular disease, and doses of 75 or 81 mg / day may optimize efficacy and safety for patients taking aspirin for long-term prophylaxis. In children with Kawasaki disease, the dose of aspirin is based on weight. The drug is started four times a day for a maximum of four weeks, and then, over the next 6-8 weeks, the drug is taken in lower doses once a day.

Side effects of aspirin

Contraindications

Aspirin is not recommended for individuals with an allergy to ibuprofen or naproxen, or for individuals with salicylate intolerance, or more generalized intolerance to NSAIDs. Caution should be observed in persons suffering from asthma or bronchospasm caused by taking NSAIDs. Because aspirin affects the stomach lining, manufacturers recommend that patients with stomach ulcers, diabetes, or gastritis consult a physician before using aspirin. Even in the absence of the above conditions, when taking aspirin together with alcohol or alcohol, the risk of stomach bleeding increases. Patients with hemophilia or other bleeding disorders are not advised to take aspirin or other salicylates. Aspirin can cause hemolytic anemia in individuals with a genetic disorder of glucose-6-phosphate dehydrogenase deficiency, especially at high doses and depending on the severity of the disease. The use of aspirin for dengue fever is not recommended because of the increased risk of bleeding. Aspirin is also not recommended for people with kidney disease, hyperuricemia, or gout because aspirin inhibits the kidney's ability to excrete uric acid and thus may exacerbate these diseases. Aspirin is not recommended for children and adolescents to treat symptoms of the flu and colds, as this use may be associated with the development of Reye's syndrome.

Gastrointestinal tract

Aspirin has been shown to increase the risk of stomach bleeding. Even though enteric coated aspirin tablets are marketed as "soft for the stomach," one study showed that even this did not help reduce the harmful effects of aspirin on the stomach. When aspirin is combined with other NSAIDs, the risk also increases. When aspirin is used in combination with clopidogrel, the risk of stomach bleeding also increases. Aspirin blockade of COX-1 induces a protective response in the form of increased COX-2. The use of COX-2 inhibitors and aspirin leads to increased erosion of the gastric mucosa. Thus, caution should be exercised when combining aspirin with any natural COX-2 inhibiting supplements such as garlic extracts, curcumin, blueberry, pine bark, ginkgo, fish oil, genistein, quercetin, resorcinol, and others. To reduce the harmful effects of aspirin on the stomach, in addition to the use of enteric coatings, manufacturing companies use the "buffer" method. Buffering agents are used to prevent the accumulation of aspirin on the stomach walls, but the effectiveness of such drugs is disputed. Almost any agent used in antacids is used as "buffers". Bufferin, for example, uses MgO. Other drugs use CaCO3. Not so long ago, vitamin C was added to protect the stomach when taking aspirin. When taken together, there is a decrease in the amount of damage compared to using aspirin alone.

The central effect of aspirin

In experiments on rats, high doses of salicylate, a metabolite of aspirin, have been shown to cause temporary tinnitus. This occurs as a result of exposure to arachidonic acid and the NMDA receptor cascade.

Aspirin and Reye's syndrome

Reye's syndrome, a rare but very dangerous disease, is characterized by acute encephalopathy and fatty liver, and develops when children and adolescents take aspirin to reduce fever or to treat other symptoms. From 1981 to 1997, 1207 cases of Reye's syndrome were recorded in the United States among patients under the age of 18. In 93% of cases, patients felt unwell three weeks before the development of Reye's syndrome, and most often complained of respiratory infections, chickenpox or diarrhea. Salicylates were found in 81.9% of children. After the link between Reye's syndrome and aspirin use was proven and safety measures were taken (including a visit from the chief sanitary officer and changes to the packaging), aspirin intake by children in the United States fell sharply, which led to a decrease in the incidence of Reye's syndrome; a similar situation was observed in the UK. The US FDA discourages aspirin or aspirin-containing foods for children under 12 years of age with fever symptoms. The UK Medicines and Medicines Regulatory Agency does not recommend taking aspirin to children under 16 without a doctor's prescription.

Allergic reactions to aspirin

In some people, aspirin can cause allergy-like symptoms, including redness and swelling of the skin and headache. This reaction is caused by an intolerance to salicylate and is not an allergy in the literal sense of the word, but rather an inability to metabolize even a small amount of aspirin, which can quickly lead to an overdose.

Other side effects of aspirin

In some people, aspirin can cause angioedema (swelling of skin tissue). One study showed that some patients develop angioedema 1-6 hours after taking aspirin. However, angioedema only developed when aspirin was taken in combination with other NSAIDs. Aspirin increases the risk of cerebral microbleeding, which on MRI shows as dark spots with a diameter of 5-10 mm or less. These bleeding may be the first signs of ischemic stroke or hemorrhagic stroke, Binswanger's disease and Alzheimer's disease. A study of a group of patients taking an average dose of aspirin 270 mg per day showed a mean absolute increase in the risk of hemorrhagic stroke equal to 12 cases among 10,000 people. In comparison, the absolute reduction in the risk of myocardial infarction was 137 cases among 10,000 people, and the reduction in the risk of ischemic stroke was 39 cases among 10,000 people. In the case of pre-existing hemorrhagic stroke, aspirin use increases the risk of mortality, with doses of about 250 mg per day lowering the risk of mortality within three months after hemorrhagic stroke. Aspirin and other NSAIDs can cause hyperkalemia by inhibiting prostaglandin synthesis; however, these drugs are not likely to cause hyperkalemia when hepatic function is normal. Aspirin can increase postoperative bleeding for up to 10 days. One study showed that 30 of 6499 patients with elective surgery required reoperations due to bleeding. Diffuse bleeding was observed in 20 patients, and local bleeding in 10 patients. In 19 of 20 patients, diffuse bleeding was associated with preoperative aspirin use alone or in combination with other NSAIDs.

Aspirin overdose

Aspirin overdose can be acute or chronic. Acute overdose is associated with a single large dose of aspirin. Chronic overdose is associated with prolonged intake of doses above the recommended rate. Acute overdose is associated with a 2% mortality risk. Chronic overdose is more dangerous and more often fatal (in 25% of cases); chronic overdose is especially dangerous in children. A variety of drugs are used for poisoning, including activated charcoal, sodium dicarbonate, intravenous dextrose and salt, and dialysis. For the diagnosis of poisoning, measurements of salicylate, an active metabolite of aspirin, in plasma are used using automated spectrophotometric methods. Plasma salicylate levels are 30-100 mg / L, 50-300 mg / L for high doses, and 700-1400 mg / L for acute overdose. Salicylate is also produced from the use of bismuth subsalicylate, methyl salicylate and sodium salicylate.

Interactions of aspirin with other drugs

Aspirin can interact with other medications. For example, azetazolamide and ammonium chloride increase the harmful effects of salicylates, while alcohol increases stomach bleeding when taking aspirin. Aspirin can displace some drugs from protein binding sites, including the antidiabetic drugs tolbutamil and chlorpropamide, methotrexate, phenytoin, probenecid, valproic acid (by interfering with beta-oxidation, an important part of valproate metabolism), and other NSAIDs. Corticosteroids can also lower the concentration of aspirin. Ibuprofen may decrease the antiplatelet effect of aspirin, which is used to protect the heart and prevent stroke. Aspirin can reduce the pharmacological activity of spironolactone. Aspirin competes with pinicillin G for renal tubular secretion. Aspirin can also inhibit the absorption of vitamin C.

Chemical characteristics of aspirin

Aspirin is rapidly degraded in solutions of ammonium acetate or acetates, carbonates, citrates or hydroxides of alkali metals. It is dry stable, but it undergoes significant hydrolysis when in contact with acetyl or salicylic acid. In the reaction with alkali, hydrolysis occurs rapidly, and the formed pure solutions can consist entirely of acetate or salicylate.

Physical characteristics of aspirin

Aspirin, an acetyl derivative of salicylic acid, is a white, crystalline, weakly acidic compound with a melting point of 136 ° C (277 ° F) and a boiling point of 140 ° C (284 ° F). The acid dissociation constant of the substance (pKa) is 25 ° C (77 ° F).

Aspirin synthesis

Aspirin synthesis is classified as an esterification reaction. Salicylic acid is treated with acetyl anhydride, an acid derivative, causing a chemical reaction that converts the hydroxy group of salicylic acid to an ester group (R-OH → R-OCOCH3). As a result, aspirin and acetylic acid are formed, which is considered a by-product of this reaction. Small amounts of sulfuric acid (and sometimes phosphoric acid) are usually used as catalysts.

The mechanism of action of aspirin

Discovery of the mechanism of action of aspirin

In 1971, British pharmacologist John Robert Wayne, who was later admitted to the Royal College of Surgeons in London, demonstrated that aspirin suppresses the production of prostaglandins and thromboxanes. For this discovery, the scientist was awarded the 1982 Nobel Prize in Medicine, together with Sune Bergström and Bengt Samuelson. In 1984 he was awarded the title of Knight Bachelor.

Suppression of prostaglandins and thromboxanes

The ability of aspirin to suppress the production of prostaglandins and thromboxanes is associated with its irreversible inactivation of the enzyme cyclooxygenase (COX; officially called prostaglandin endoperoxide synthase), associated with the synthesis of prostaglandin and thromboxane. Aspirin acts as an acetylating agent when an acetyl group is covalently attached to a residue on the active site of the COX enzyme. This is the main difference between aspirin and other NSAIDs (such as diclofenac and ibuprofen), which are reversible inhibitors. Low-dose aspirin irreversibly blocks the formation of thromboxane A2 in platelets, inhibiting platelet aggregation during their life cycle (8–9 days). Due to this antithrombotic action, aspirin is used to reduce the risk of heart attack. Aspirin 40 mg per day can inhibit a large percentage of the maximum release of thromboxane A2, with little effect on prostaglandin I2 synthesis; however, high doses of aspirin may increase inhibition. Prostaglandins, a local hormone produced in the body, have a variety of effects, including the transmission of pain signals to the brain, modulation of the hypothalamic thermostat, and inflammation. Thromboxanes are responsible for the aggregation of platelets, which form blood clots. The main cause of heart attack is blood clotting, and low-dose aspirin is recognized as an effective means of preventing acute myocardial infarction. An undesirable side effect of the antithrombotic action of aspirin is that it can cause excessive bleeding.

Inhibition of COX-1 and COX-2

There are at least two types of cyclooxygenase: COX-1 and COX-2. Aspirin irreversibly inhibits COX-1 and modifies the enzymatic activity of COX-2. COX-2 usually produces prostanoids, most of which are pro-inflammatory. Aspirin-modified PTGS2 produces lipoxins, most of which are anti-inflammatory. To inhibit PTGS2 alone and reduce the risk of gastrointestinal side effects, a new generation of NSAIDs, COX-2 inhibitors, have been developed. However, more recently, new generation COX-2 inhibitors such as rofecoxib (Vioxx) have been taken off the market following reports that PTGS2 inhibitors increase the risk of heart attack. Endothelial cells express PTGS2 and, by selectively inhibiting PTGS2, reduce prostaglandin (ie, PGI2; prostacyclin) production, depending on thromboxane levels. Thus, the protective anticoagulant effect of PGI2 decreases and the risk of blood clots and heart attacks increases. Since platelets do not have DNA, they cannot synthesize new PTGS. Aspirin irreversibly inhibits the enzyme, which is its most important difference from reversible inhibitors.

Additional mechanisms of action of aspirin

Aspirin has at least three additional mechanisms of action. It blocks oxidative phosphorylation in cartilaginous (and renal) mitochondria by diffusing from a portion of the inner membrane as a proton carrier back into the mitochondrial space, where it re-ionizes to release protons. In short, aspirin buffers and transports protons. When taken in high doses, aspirin can cause fever due to the thermal release from the electron transport chain. In addition, aspirin promotes the formation of NO-radicals in the body, which has been shown in experiments on mice to be an independent mechanism for reducing inflammation. Aspirin reduces leukocyte adhesion, which is an important immune defense mechanism against infections; however, these data are not conclusive evidence of the effectiveness of aspirin against infections. Newer data also show that salicylic acid and its derivatives modulate signaling through NF-κB. NF-κB, a transcription factor complex, plays an important role in many biological processes, including inflammation. In the body, aspirin quickly breaks down to salicylic acid, which itself has anti-inflammatory, anti-temperature and analgesic effects. In 2012, salicylic acid was shown to activate AMP-activated protein kinase, which may be a possible explanation for some of the effects of salicylic acid and aspirin. The acetyl in the aspirin molecule also has a special effect on the body. Acetylation of cellular proteins is an important phenomenon that affects the regulation of protein function at the post-translational level. Recent research shows that aspirin can acetylate more than COX isoenzymes. These acetylation reactions may explain many of the hitherto unexplained effects of aspirin.

Hypothalamic-pituitary-adrenal activity

Aspirin, like other drugs that affect prostaglandin synthesis, has a powerful effect on the pituitary gland, and indirectly affects some hormones and physiological functions. The effects of aspirin on growth hormone, prolactin and thyroid stimulating hormone have been directly proven (with relative effects on T3 and T4). Aspirin reduces the effect of vasopressin and increases the effect of naloxone by secreting adrenocorticotropic hormone and cortisol in the hypothalamic-pituitary-adrenal axis, which occurs through interaction with endogenous prostaglandins.

Pharmacokinetics of aspirin

Salicylic acid is a weak acid and very little of it ionizes in the stomach after oral administration. Acetylsalicylic acid is poorly soluble in the acidic environment of the stomach, so its absorption can be delayed by 8-24 hours when taken in high doses. The increased pH and large area of \u200b\u200bcoverage of the small intestine promotes rapid absorption of aspirin in this area, which, in turn, promotes greater dissolution of the salicylate. However, in case of overdose, aspirin dissolves much more slowly, and its plasma concentrations can increase within 24 hours after ingestion. About 50–80% of salicylate in the blood binds to protein, and the rest remains in the active ionized form; protein binding is concentration dependent. The saturation of the binding sites leads to an increase in the amount of free salicylate and an increase in toxicity. The volume of distribution is 0.1–0.2 l / kg. Acidosis increases the volume of distribution due to increased cellular penetration of salicylates. 80% of the therapeutic dose of salicylic acid is metabolized in the liver. When bound with, salicylic acid is formed, and with glucuronic acid, salicylic acid and phenolic glucuronide are formed. These metabolic pathways have only limited capabilities. A small amount of salicylic acid is also hydrolyzed to gentisic acid. When large doses of salicylate are taken, kinetics shifts from first to zero order as metabolic pathways become saturated and the importance of renal excretion increases. Salicylates are excreted from the body by the kidneys in the form of salicylic acid (75%), free salicylic acid (10%), salicylic phenol (10%) and acyl glucuronides (5%), gentisic acid (< 1%) и 2,3-дигидроксибензойной кислоты. При приеме небольших доз (меньше 250 мг у взрослых), все пути проходят кинетику первого порядка, при этом период полувыведения составляет от 2.0 до 4.5 часов. При приеме больших доз салицилата (больше 4 г), период полураспада увеличивается (15–30 часов), поскольку биотрансформация включает в себя образование салицилуровой кислоты и насыщение салицил фенольного глюкоронида. При увеличении pH мочи с 5 до 8 наблюдается увеличение почечного клиренса в 10-20 раз.

History of the discovery of aspirin

Herbal extracts, including willow bark and meadowsweet (spirea), whose active ingredient is salicylic acid, have been used since ancient times to relieve headaches, pain and fever. The father of modern medicine, Hippocrates (460 - 377 BC), described the use of willow bark and leaf powder to relieve such symptoms. French chemist Charles Frederic Gerhard first made acetylsalicylic acid in 1853. While working on the synthesis and properties of various acidic anhydrides, he mixed acetyl chloride with the sodium salt of salicylic acid (sodium salicylate). A violent reaction ensued and the resulting alloy was modified. Gerhard named this compound "salicyl acetyl anhydride" (wasserfreie Salicylsäure-Essigsäure). 6 years later, in 1859, von Gilm obtained analytically pure acetylsalicylic acid (which he called acetylierte Salicylsäure, acetylated salicylic acid) by the reaction of salicylic acid and acetyl chloride. In 1869, Schroeder, Prinzorn and Kraut repeated the experiments of Gerhard and von Hilm and reported that both reactions lead to the synthesis of the same substance - acetylsalicylic acid. They were the first to describe the correct structure of a substance (in which an acetyl group is attached to phenolic oxygen). In 1897, chemists at Bayer AG produced a synthetically modified version of salicin, extracted from the plant Filipendula ulmaria (meadowsweet), which causes less stomach irritation than pure salicylic acid. It is still not clear who was the main chemist who conceived this project. Bayer said the work was carried out by Felix Hoffmann, but Jewish chemist Arthur Eichengrun later stated that he was the main developer and that his contributions were destroyed during the Nazi regime. The new drug, formally acetylsalicylic acid, has been named "Aspirin" by Bayer AG, after the old botanical name of the plant that contains it (meadowsweet), Spiraea ulmaria. The word "Aspirin" is derived from the words "acetyl" and "Spirsäure", an old German word for salicylic acid, which in turn comes from the Latin "Spiraea ulmaria". By 1899, Bayer was already selling aspirin around the world. The popularity of aspirin increased in the first half of the 20th century, thanks to its supposed effectiveness in treating the 1918 Spanish flu epidemic. Recent research, however, suggests that aspirin caused part of the 1918 flu deaths, but this claim is controversial and not widely accepted in academia. The popularity of aspirin led to fierce competition and divisions of aspirin brands, especially after Bayer's US patent expired in 1917. After the introduction of (acetaminophen) on the market in 1956 and ibuprofen in 1969, the popularity of aspirin declined somewhat. In the 1960s and 1970s, John Wayne and his team discovered the basic mechanisms of action of aspirin, and clinical trials and other studies conducted between the 1960s and 1980s. demonstrated that aspirin is an effective anti-clotting drug. In the last decades of the 20th century, sales of aspirin increased again, and remain at a fairly high level to this day.

Aspirin brand

As part of the 1919 Treaty of Versailles reparations following Germany's defeat in World War I, aspirin (as well as heroin) lost their registered trademark status in France, Russia, Great Britain and the United States, where they became generics. Aspirin is currently considered generic in Australia, France, India, Ireland, New Zealand, Pakistan, Jamaica, Colombia, Philippines, South Africa, the United Kingdom and the United States. Aspirin, capital "A", remains a registered trademark of Bayer in Canada, Germany, Mexico and over 80 other countries where the trademark is owned by Bayer.

Veterinary use of aspirin

Aspirin is sometimes used to relieve pain or as an anticoagulant in veterinary medicine, primarily in dogs and sometimes in horses, although new drugs with fewer side effects are currently being used. Dogs and horses have gastrointestinal side effects of aspirin associated with salicylates, but aspirin is often used to treat arthritis in older dogs. Aspirin has been shown to be effective against laminitis (inflammation of the foot) in horses, but is no longer used for this purpose. Aspirin can only be used in animals under close medical supervision; in particular, the cat's body lacks glucoronide conjugates that promote the excretion of aspirin, as a result of which even small doses of the drug can be potentially toxic to them.