Acetylsalicylic acid

ATC code

N02BA01

Therapeutic class

Analgesic, antipyretic, non-steroidal anti-inflammatory drug (NSAID) and antiplatelet agent · Salicylate

Forms

oral tablet

Brand names

A.A.S. (ES) · Aspirin (US) · Bayer Aspirin (US) · Aspro (FR)

Overall confidence

medium

Regulatory sources consulted

AEMPS-CIMA-FT-42956
PMID:11724833
CredibleMeds.org
JACC 2019;73(24):e290-e309
AEMPS CIMA · nº registro 42956 ↗

Approved indications

Symptomatic treatment of occasional mild to moderate pain (headaches, dental pain, menstrual pain, muscle pain, low back pain). Febrile states.
Secondary prevention of cardiovascular events (myocardial infarction, ischemic stroke) in high-risk patients.

Contraindications

Absolute

Hypersensitivity to salicylates or NSAIDs, active peptic ulcer, bleeding diathesis, severe renal or hepatic failure, third trimester of pregnancy.

Clinical warnings

Major warning · Reye's Syndrome: Do not use in children or adolescents (<16 years) with viral infections (flu, chickenpox) due to the risk of Reye's Syndrome, a rare but serious illness. — AEMPS CIMA
Major warning · Risk of gastrointestinal bleeding, ulceration, and perforation. Use with caution in patients with a history of gastrointestinal disease or on anticoagulant therapy. — AEMPS CIMA

Drug interactions

HighMethotrexateL01BA01
Mechanism: Decreased renal clearance of methotrexate, increasing its hematological toxicity.
Recommendation: Concomitant use with methotrexate doses ≥15 mg/week is contraindicated. Strict monitoring is required with lower doses.
AEMPS CIMA
ModerateIbuprofenM01AE01
Mechanism: Ibuprofen may interfere with the irreversible antiplatelet effect of low-dose aspirin, potentially reducing its cardiovascular protection.
Recommendation: Administer aspirin at least 30 minutes before or ≥8 hours after ibuprofen to minimize the interaction. Consider alternative NSAIDs in patients requiring cardioprotection.
PMID:11724833

Adverse events

Common (≥1%)

dyspepsia · abdominal pain · nausea · increased bleeding risk

Rare but serious

major gastrointestinal bleeding · Reye's syndrome · anaphylaxis · acute renal failure

Pregnancy and lactation

FDA category: D

Contraindicated in the third trimester of pregnancy. During the first and second trimesters, use only if strictly necessary. It is excreted in breast milk, so its use during lactation is not recommended.