Aspirin

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File:Http://pillsnorx24x7.com/?search=aspirin&lang=en&q=aspirin Asprin is one of the oldest medications available to man. It has a mild, non-narcotic analgesic effect that relieves pain. It also prevents fever and inflammation. Its ability to prevent platelets from forming clots makes it one of the most common over-the-counter maintenance medications for senior citizens. This drug should be taken on a full stomach.

Contents

History

Hippocrates left historical records of pain relief treatment, which included the use of powdered bark and leaves of the willow tree to cure headaches, pains and fever. In 1828, Johann Buchner, a pharmacy professor at Munich, had isolated a small quantity of bitter, yellow, needle-like crystals which he called “salicin” The following year, Henri Leroux improved extraction of salicin in its crystal form. By 1838, Raffaele Pira succeeded in obtaining pure salicylic from salicin.

Salicylic acid, despite exerting its analgesic effect, needed to be buffered to be used safely on humans. Charles Frederic Gerhardt neutralized it with sodium and acetyl chloride in 1853 but abandoned his discovery. Felix Hoffman, a chemist who works for Bayer, rediscovered Gerhardt's formula in 1899. Bayer patented Aspirin in February 27, 1900.

Bayer came up with Aspirin's name by combining “A” from acetyl chloride, “spir” from the scientific name of meadowsweet, the plant where they derived salicylic acid, and “in” was a familiar name ending for drugs during that period. It was initially sold as a powder but by 1915, the tablet version was made available to the public.

Chemistry

Aspirin is a generic name. Its common chemical name is acetyl salicylic acid but its systematic name is 2-(acetyloxy) benzoic acid. ASA is a common abbreviation.

Popular brands in the Philippines are oral tablets such as Aspilet EC®, Aspen EC®, Cortal® and Tromcor® . Generic brands from Bayer and Rhea are also available in local pharmacies. Suppositories are available in other countries.

The drug inhibits cyclooxygenase which makes prostaglandin and thromboxane. Prostaglandin causes inflammation, pain, and fever. Thromboxane is responsible for the formation of blood clots. Its effects are observable 1 to 2 hours after ingestion and will last for 4 to 6 hours.

Uses and common dosages

Aspirin is given at 75 to 325 mg once a day for preventing heart attacks. 325 to 650 mg every 4 to 6 hours for a maximum of 4 grams/day is recommended for mild to moderate pain and fever. Pain and muscle soreness can be relieved by 3.6 to 5.4 grams/day in divided doses.

Children are usually given aspirin to treat juvenile rheumatoid arthritis (up to 130 mg/Kg daily).However, patients younger than 16 years old must not be given aspirin for flu or chickenpox as it risks contracting Reye's syndrome. Minors who have asthma, bleeding problems, nasal polyps or rhinitis should not also be given aspirin.

To prevent blood clots to form on the stent, 325 mg aspirin may also be given 2 hours before stent implantation and 160 to 325 mg/day afterwards. In some cases, it may be given to treat rheumatic fever and Kawasaki disease.

Side effects and adverse drug reactions

Common side effects of aspirin use are nausea, vomiting, stomach pain or heartburn.

Serious side effects that should be reported to the doctor immediately are the following:

  • Hives or rashes
  • Swollen face, throat, or tongue
  • Any difficulty in breathing
  • Any discolored stool (black or bright red)
  • Ringing in the ears or loss of hearing
  • Vomit that has blood or looks like coffee grounds

Precautions and contraindications

Aspirin should be used with caution

  • On pregnant women only if there is potential benefit, especially if given its full dose given at the last trimester. There is sufficient evidence that it might harm the fetus such as reduced birth weight or heart damage.
  • By patients who have asthma, stomach ulcers, congestive heart failure, high blood pressure, seasonal allergies, gout, nasal polyps, liver, or kidney disease. Their doctors may require them to undergo certain tests or have doses adjusted for them to safely take aspirin.

Aspirin should NEVER be used

  • By nursing women, as it passes to breast milk which may harm the baby
  • By people who have recently experienced stomach or intestinal bleeding
  • On hemophiliacs and those affected with other bleeding disorders
  • By those who have experienced allergies to other NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)
  • A week before elective surgery due to risk of heavy bleeding.

Interactions

Aspirin and other substances

Ibuprofen must be avoided when taking this medication. It lowers aspirin's ability to protect the heart and blood vessels. If it cannot be avoided, take ibuprofen 30 minutes after or 8 hours before taking aspirin.

Alcohol must also be avoided. It will increase the risk of stomach bleeding.

Antihypertensive medications, such as drugs that end in -pril (ACE Inhibitors) have little or not effect when given with aspirin.

Methotrexate (15 mg or more per week) or aminoglycoside antibiotics (like gentamcin) elimination from the body are reduced when given with aspirin, leading to more side effects.

Blood thinners, like warfarin, should NOT be given with aspirin as it would lead to serious bleeding.

Aspirin and laboratory tests

Aspirin may cause false test results, especially in certain urine sugar tests.

Overdose

Too much aspirin use may include symptoms which include:

  • Burning pain in the throat or stomach
  • Confusion, seizures, or mental/mood changes
  • Fainting and/or weakness
  • Ringing in the ears
  • Fever
  • Rapid breathing
  • Changes in amount of urine

References