NSAIDs: Safety concerns

Last updated: October 08, 2018

Inflammation is a normal physiological reaction to injury and is intended to aid tissue repair. Prostaglandins are important triggers of this response and are produced from arachidonic acid, a constituent of cell membranes.


NonSteroidal Anti-Inflammatory Drugs or NSAIDs treat the pain associated with inflammation by blocking the action of the enzyme cyclo-oxygenase ('COX') which mediates prostaglandin production.

Although prostaglandins cause inflammation and pain, they have other beneficial effects. For example, they protect the gastrointestinal mucosa from damage, encourage blood flow to the kidney, help to control blood clotting, and assist some aspects of healing. By removing these protective functions of prostaglandins, your NSAID prescription can cause significant side effects:

• They can cause GI ulceration and bleeding which might start with less severe symptoms such as gastritis or indigestion, but can present as a sudden life-threatening GI haemorrhage.
• NSAIDs may impair blood flow to the kidney resulting in a deterioration in renal function. The resulting fluid retention can exacerbate pre-existing heart failure and  may require doses of any antihypertensives and diuretics to be increased. The MHRA offers advice about renal impairment due to NSAIDs.
• The net effect of NSAIDs is to make blood more likely to clot. Drugs such as the coxibs or diclofenac have the most potent effect, but all NSAIDs cause this to some extent. It means that NSAIDs can increase the risk of myocardial infarction and strokes.
• In older adults, NSAIDs may impair healing of fractures so NICE states that they should not be used in this patient group.

There are, of course, other NSAID side effects too, such as hypersensitivity reactions. This tutorial focuses on the serious GI side effects of NSAIDs but when choosing a medicine for your patient, prescribers need to be aware of all the side effects of NSAIDs.