What is the information about Acetylsalicylic acid (Aspirin)?

From the Guidelines

Aspirin should be used with caution, considering its benefits and risks, particularly in patients with a high risk of cardiovascular disease, as it can reduce the risk of serious vascular events by 12% (1).

Benefits and Risks of Aspirin

Aspirin is a widely used medication that belongs to the nonsteroidal anti-inflammatory drug (NSAID) class. It's primarily used to relieve pain, reduce inflammation, and lower fever. The standard adult dose for pain relief is 325-650 mg every 4-6 hours as needed, not exceeding 4,000 mg daily. For heart attack prevention, a lower dose of 81-100 mg daily is typically recommended. Aspirin works by inhibiting cyclooxygenase enzymes, which reduces the production of prostaglandins responsible for pain and inflammation. It also has antiplatelet effects, making it valuable for preventing blood clots in people at risk for heart attacks and strokes.

Key Considerations

• Aspirin has been shown to be effective in reducing cardiovascular morbidity and mortality in high-risk patients with previous MI or stroke (secondary prevention) and is strongly recommended (1).
• In primary prevention, however, among patients with no previous cardiovascular events, its net benefit is more controversial (1).
• The main adverse effect of aspirin is an increased risk of gastrointestinal bleeding, with the excess risk being as high as 5 per 1,000 per year in real-world settings (1).
• Aspirin should be taken with food to minimize stomach upset, and it's not recommended for children with viral illnesses due to the risk of Reye's syndrome, a rare but serious condition.
• People with bleeding disorders, stomach ulcers, or aspirin allergies should avoid it, and you should consult a healthcare provider before starting regular aspirin therapy, especially for heart health purposes.

Recent Guidelines and Studies

• The ASCEND (A Study of Cardiovascular Events iN Diabetes) trial randomized 15,480 patients with diabetes but no evident cardiovascular disease to aspirin 100 mg daily or placebo, and found a significant 12% reduction in the primary efficacy end point (1).
• The USPSTF determined with moderate certainty that the net benefit in life-years and QALYs gained from aspirin use is moderate in adults aged 50 to 59 years, and small in adults aged 60 to 69 years (1).
• A recent study found that the optimal dose of aspirin for ATAD (aspirin therapy for aspirin-exacerbated respiratory disease) is not clear, and most clinical trials used 650 to 1300 mg per day (1).

From the FDA Drug Label

Warnings Reye's syndrome: Children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use this product, if changes in behavior with nausea and vomiting occur, consult a doctor because these symptoms could be an early sign of Reyes syndrome, a rare but serious illness Allergy alert: Aspirin may cause a severe allergic reaction which may include: hives, facial swelling, asthma(wheezing), shock Stomach bleeding warning: This product contains an NSAID, which may cause severe stomach bleeding The chance is higher if you are age 60 or olderHave had stomach ulcers or bleeding problemsTake a blood thinning (Anticogulant) or steroid drugTake other drugs containing prescription or nonprescription NSAIDs (aspirin, ibuprofen, naproxen, or others)have 3 or more alcoholic drinks every day using this product Aspirin is a medication with several warnings and precautions, including:

• Reye's syndrome: a rare but serious illness that can occur in children and teenagers recovering from chicken pox or flu-like symptoms
• Allergic reactions: severe reactions that can include hives, facial swelling, asthma, and shock
• Stomach bleeding: a risk that is higher in certain individuals, such as those over 60, with stomach ulcers or bleeding problems, or taking certain medications 2

From the Research

Aspirin Mechanism and Usage

• Aspirin inhibits platelet function by irreversibly inhibiting the synthesis of thromboxane A2 (TxA2) 3
• Aspirin is widely used for cardiovascular prevention, particularly at low doses 3, 4
• The use of aspirin for primary prevention of cardiovascular disease has been subject to controversy over the past decades 4

Aspirin Formulations and Efficacy

• Different formulations of aspirin have been developed, including enteric-coated (EC) aspirin, to reduce gastrointestinal adverse effects 3
• EC aspirin is less effective than plain aspirin in inhibiting TxA2 production, especially in subjects with high body weight 3
• Plain aspirin should be the preferred formulation for cardiovascular prevention due to its favorable pharmacological profile 3

Aspirin Dosing and Cardiovascular Disease Prevention

• The appropriate dose of aspirin for cardiovascular disease prevention is a subject of controversy 5, 6
• Clinical data suggest that dosages greater than 75 to 81 mg/d do not enhance efficacy and are associated with an increased incidence of bleeding events 5
• A comparative effectiveness study found no significant differences in cardiovascular events or major bleeding between patients assigned to 81 mg and those assigned to 325 mg of aspirin daily 6

Recommendations for Aspirin Use

• The US Preventive Services Task Force recommends against initiating low-dose aspirin use for the primary prevention of cardiovascular disease in adults 60 years or older 7
• The decision to initiate low-dose aspirin use for primary prevention in adults aged 40 to 59 years who have a 10% or greater 10-year cardiovascular disease risk should be an individual one 7