Even though aspirin and Ibuprofen are both NSAIDs (nonsteroidal anti-inflammatory drugs) and work similarly, that is by blocking the body’s production of prostaglandins which relieves pain and inflammation, there are several differences between the two drugs and they are not considered interchangeable.

The main differences between aspirin and ibuprofen are:

• Aspirin is significantly more likely than low-dose ibuprofen to cause gastrointestinal side effects. The risk of other side effects is similar
• Aspirin should not be used in children under 12 years of age or those under the age of 16 with a viral illness because of the risk of Reye’s syndrome. Ibuprofen is approved for use in children over the age of 6 months and may be given to children with a viral illness
• Aspirin may be used at a low dose to reduce the risk of a heart attack or stroke or to prevent blood clotting. Ibuprofen has less of an effect on blood cells or platelets so is not used for this indication
• Aspirin is also a salicylate because it is derived from salicylic acid. Some people are sensitive to salicylates; symptoms may include asthma-like reactions, nasal congestion, and hives
• Ibuprofen is preferred over aspirin for ongoing conditions such as arthritis, menstrual cramps, and back pain. This is because the risk of gastrointestinal side effects increases the longer the duration of treatment and the risk of GI effects associated with aspirin use is already high. Aspirin may be used on an occasional basis to treat headaches, minor body aches, and tooth pain
• Aspirin use does not appear to be associated with a higher risk of cardiovascular events, nor does low-dose ibuprofen (up to 1200mg/day). However, high-dose ibuprofen (1200mg to 2400mg/day) is associated with a higher risk. People with a history of heart disease or stroke should use NSAIDs with caution and they should not be used after coronary artery bypass graft (CABG) surgery.

Other points to note include:

• Generic aspirin is available and brand names for aspirin include Bayer Aspirin, Ecotrin, and Bufferin
• Generic ibuprofen is available and brand names for ibuprofen include Motrin and Advil
• Neither aspirin or ibuprofen is recommended during pregnancy
• People with gastrointestinal disorders, bleeding disorders or hemophiliacs should avoid aspirin and should only take ibuprofen if recommended and monitored by their doctor
• Aspirin and ibuprofen should not be taken together. If you are prescribed aspirin to reduce your risk of heart attack or stroke, talk with your doctor before taking any NSAIDs, as these may negate the protective effect of aspirin
• Both aspirin and ibuprofen may cause kidney toxicity and allergic-type reactions. Interactions are also similar, with both aspirin and ibuprofen interacting with angiotensin-II receptor blockers (ARBs), diuretics, clopidogrel, warfarin, dabigatran, and aspirin.

Important Guidance

When taking any NSAID, the following guidance is given:

• Acetaminophen is preferred over NSAIDs, when appropriate
• If an NSAID is deemed necessary, take only the lowest possible dose for the shortest possible time
• Naproxen (in dosages up to 1000mg/day) and ibuprofen (in dosages up to 1200mg/day) are the preferred NSAIDs. Ibuprofen is the most appropriate NSAID for children
• Avoid using long-acting formulations of NSAIDs as these have a higher risk of GI side effects
• Do not take any other NSAID-containing products while being treated with an NSAID
• Doctors should review the need for continued NSAID administration at each consultation
• In people with pre-existing heart disease or who have suffered a heart attack or stroke, NSAIDs should only be used with caution and only under a doctor's supervision
• Older patients, patients with type 2 diabetes or with a history of stomach ulcers, kidney problems or at risk for heart disease are more likely to suffer from NSAID-related complications such as GI side effects, cardiovascular events, and kidney toxicity. NSAIDs should be avoided, but if deemed necessary, their usage should be monitored by a doctor.