Aspirin is a widely used medication for pain relief, fever reduction, and inflammation. The appropriate dose depends on the health concern, making it important to understand when a dosage is suitable or excessive for safe use.
Understanding Aspirin Dosages
A 325 mg aspirin tablet is a standard adult dose for temporary relief of common ailments like headaches, muscle aches, toothaches, menstrual pain, and fever. For these purposes, adults typically take one to two 325 mg tablets every four to six hours as needed. It is important not to exceed a total of 3900 mg within a 24-hour period for pain or fever.
This dosage may also be used as an initial treatment for certain acute cardiovascular events, such as a suspected heart attack, but this is a specific, short-term medical intervention under professional supervision. In contrast, low-dose aspirin, usually 81 mg, is prescribed for daily cardiovascular prevention. The 325 mg dose is generally not used for long-term prevention due to increased risks.
When 325 mg May Be Excessive
Taking 325 mg of aspirin may be excessive in several situations, particularly for long-term daily use. For chronic cardiovascular prevention, 325 mg is typically too high. It significantly increases bleeding risk, especially in the gastrointestinal tract, compared to the 81 mg dose. Higher doses and repeated use also increase the likelihood of side effects like stomach ulcers, heartburn, nausea, general stomach upset, and bruising.
Aspirin, including 325 mg, should be avoided or used with caution by individuals with bleeding disorders (e.g., hemophilia, low platelet counts), active stomach ulcers, or a history of severe gastrointestinal bleeding. Allergic reactions to aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) can manifest as hives, itchy rashes, blocked or runny nose, asthma, or more severe reactions like anaphylaxis.
Aspirin is not recommended for children or teenagers recovering from viral infections, such as the flu or chickenpox, due to the risk of Reye’s syndrome. This rare but serious condition causes brain swelling and liver damage and can be fatal.
Caution is advised when combining 325 mg aspirin with other medications, such as anticoagulants (e.g., warfarin, heparin), other NSAIDs, or methotrexate, due to potential drug interactions.
During pregnancy, especially in the third trimester, higher aspirin doses can increase bleeding risk in premature infants and may cause premature closure of a fetal heart vessel. The FDA advises against NSAIDs, including aspirin, after 19 weeks due to concerns about fetal kidney problems. While 81 mg aspirin may be prescribed for specific conditions like preeclampsia under medical supervision, higher doses are not recommended.
For individuals with kidney disease, aspirin’s impact is complex. While low-dose aspirin may not pose a renal failure risk, higher risks exist for those with advanced chronic kidney disease and anemia.
High doses of aspirin can lead to elevated liver enzymes and, rarely, liver injury. Patients with liver conditions like cirrhosis may also face an increased bleeding risk.
Recognizing Overdose and Seeking Medical Attention
Aspirin overdose (salicylate toxicity) can manifest with various symptoms. Early signs include ringing in the ears (tinnitus), nausea, vomiting, and stomach pain. As toxicity progresses, individuals may experience rapid breathing, dizziness, confusion, fever, and unusual bleeding or bruising. Severe signs include impaired hearing, double vision, drowsiness, unsteady walking, seizures, and coma.
If severe symptoms occur, such as difficulty breathing, seizures, or loss of consciousness, seek immediate emergency medical attention. Call 911 or your local emergency number.
For less severe symptoms or concerns about accidental overdose, contact a poison control center. The national Poison Help hotline is 1-800-222-1222 in the United States.
Following dosage instructions and keeping medications out of reach of children are important preventive measures against accidental overdose.