Enteric aspirin, sometimes called safety aspirin, is coated so that it doesn't dissolve in the stomach but instead dissolves in the small intestine. This quality prevents stomach upset. But the coating doesn't protect against the bleeding and ulceration that can occur after frequent aspirin use.
Aspirinenteric or nothinders the production of prostaglandins that protect the stomach lining. This occurs no matter where the aspirin dissolves in the body.
Some, but not all, studies suggest that people using aspirin therapy to reduce their risk of stroke or heart attack may need a higher dosage if they use enteric aspirin, because the coating may interfere with aspirin's anticlotting effect (for example, 162 mg enteric aspirin versus 81 mg uncoated aspirin).
Nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen products, also can interfere with aspirin's anticlotting effect. If you must take other NSAIDs while using aspirin to prevent a heart attack or to ease pain, ask your doctor how to time your doses of the two drugs.
Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50