Aspirin, or acetylsalicylic acid, is a widely used medication. It functions as a nonsteroidal anti-inflammatory drug (NSAID), working by inhibiting substances in the body that cause pain, fever, and inflammation. Aspirin also affects platelets, making them less likely to clump together, which is useful in preventing blood clots.
Dosage for Common Ailments
For temporary relief of minor pain and fever in adults, aspirin is commonly available in tablet strengths of 325 mg or 500 mg. The typical adult dosage for conditions like headaches, muscle aches, menstrual pain, or toothaches is 325 mg to 650 mg taken orally every 4 to 6 hours as needed. It is important to drink a full glass of water with each dose.
The maximum daily dosage for adults should not exceed 3,900 mg to 4,000 mg within a 24-hour period. This means taking no more than 12 tablets of 325 mg aspirin in 24 hours, with at least a 4-hour interval between doses. For self-treatment of fever, aspirin should not be used for more than 3 consecutive days, and for pain, no more than 10 consecutive days without consulting a healthcare provider. Aspirin is also available as rectal suppositories, with typical doses ranging from 150 mg to 900 mg every 4 hours, not exceeding 12 of the 300 mg suppositories or 24 of the 150 mg suppositories in 24 hours.
Dosage for Heart and Stroke Prevention
Aspirin plays a role in cardiovascular health, often prescribed in lower doses to prevent heart attacks and strokes. This is commonly referred to as “low-dose” or “baby” aspirin, typically ranging from 75 mg to 100 mg, with 81 mg being a very common dosage. This lower dose works by making blood platelets less sticky, which helps prevent blood clots from forming in arteries.
This daily regimen is usually recommended for individuals with a history of heart attack, stroke, or known heart disease to prevent recurrence. For primary prevention, daily low-dose aspirin may be considered for adults aged 40 to 59 who have a 10% or higher risk of developing cardiovascular disease within the next 10 years, provided they have a low risk of bleeding. Individuals aged 60 or older without known heart disease are generally advised against starting daily aspirin for primary prevention, as the risks of bleeding may outweigh the benefits. This therapy should always be initiated under the guidance of a healthcare professional.
Aspirin and Children
Aspirin should be avoided for children and teenagers, especially those recovering from viral infections like the flu or chickenpox. This is due to a rare but serious condition known as Reye’s Syndrome. Reye’s Syndrome can cause sudden brain damage and liver problems, potentially leading to irreversible brain damage or even death.
While Reye’s Syndrome has become much rarer since aspirin use in children decreased, it remains a serious concern. The condition develops within a week of a viral illness, with initial symptoms including persistent vomiting and confusion. Parents and caregivers should consult a pediatrician for pain or fever relief in children and adolescents, and avoid giving aspirin or products containing aspirin-like compounds such as salicylates. Alternative medications commonly recommended for children’s pain and fever relief include acetaminophen or ibuprofen.
When to Avoid or Adjust Dosage
Aspirin use, or its typical dosage, may be inappropriate or require medical consultation in several situations due to potential risks. Individuals with active bleeding disorders, a history of gastrointestinal bleeding, or stomach ulcers should avoid aspirin because it can worsen bleeding and may lead to life-threatening complications. Those with severe liver or kidney disease should also use caution, as aspirin is metabolized in the liver and can affect kidney function.
Patients with asthma may experience bronchospasm when taking aspirin. If you are taking other blood thinners, such as warfarin, heparin, apixaban, dabigatran, enoxaparin, or rivaroxaban, combining them with aspirin can significantly increase the risk of major bleeding. Before any surgery or dental work, it is important to inform your healthcare professional about aspirin use, as it may need to be stopped several days prior to the procedure to prevent excessive bleeding. Always consult a healthcare professional before starting or changing aspirin dosage, especially for long-term use or if pre-existing conditions are present.