NSAIDs

What it is

NSAIDs are non-steroidal anti-inflammatory drugs that reduce pain, fever, and inflammation by blocking cyclo-oxygenase enzymes. An important safety fact is that two COX-2 selective NSAIDs, rofecoxib and valdecoxib, were withdrawn from the market in 2004 and 2005 because of safety concerns. This drug class includes common medicines such as ibuprofen, naproxen, diclofenac, indomethacin, ketorolac, meloxicam, celecoxib, and aspirin, although aspirin is often discussed separately because of its antiplatelet use.

NSAIDs are widely used for short-term problems such as headache, sprains, dental pain, fever, painful periods, and viral illness symptoms, and for longer-term inflammatory conditions such as osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and gout. Some are taken by mouth, some are given by injection, and some are used on the skin as gels or patches. Topical diclofenac is an example that can help localized musculoskeletal pain with lower whole-body exposure than tablets.

A simple way to group NSAIDs is by selectivity and route:

Group	Examples	Key point
Non-selective NSAIDs	ibuprofen, naproxen, diclofenac, indomethacin, ketorolac	Block both COX-1 and COX-2 to varying degrees
COX-2 selective NSAIDs	celecoxib, etoricoxib	Designed to reduce stomach toxicity, but cardiovascular risk still matters
Topical NSAIDs	diclofenac gel/patch	Useful for localized pain with less systemic absorption

In India, many NSAIDs are available over the counter or are commonly self-used, especially ibuprofen and diclofenac preparations. That makes pharmacist guidance important, because combining products or using them for too many days is a common source of harm.

How it works

NSAIDs mainly work by inhibiting cyclo-oxygenase enzymes, called COX-1 and COX-2. These enzymes help the body make prostaglandins, which are signaling molecules involved in pain, inflammation, fever, protection of the stomach lining, kidney blood flow, and platelet function.

When prostaglandin production falls, pain and inflammation often improve. That is why NSAIDs can help with swollen joints, menstrual cramps, and inflammatory injuries. They also lower fever because prostaglandins are involved in the brain's temperature set point.

The same mechanism explains many adverse effects. COX-1 activity helps protect the stomach and supports platelet function, so blocking it can increase the risk of gastritis, ulcers, and bleeding. Prostaglandins also help maintain kidney blood flow, especially when a person is dehydrated, older, has heart failure, or has chronic kidney disease. In those settings, NSAIDs can trigger acute kidney injury.

Different NSAIDs have different balances of COX-1 and COX-2 inhibition, half-lives, and tissue penetration. That is why one drug may be preferred over another for a specific situation, but no NSAID is completely free of gastrointestinal, kidney, or cardiovascular risk.

Evidence and uses

NSAIDs have strong evidence for short-term relief of mild to moderate pain and for many inflammatory conditions. They are commonly used for musculoskeletal injuries, osteoarthritis flares, dysmenorrhea, dental pain, postoperative pain, migraine, gout, and fever. In some settings they reduce the need for opioids.

Common clinical uses include:

1. Acute pain: headache, toothache, sprains, strains, back pain.
2. Inflammatory joint disease: osteoarthritis, rheumatoid arthritis, ankylosing spondylitis.
3. Menstrual pain: often effective because prostaglandins contribute to uterine cramping.
4. Gout flares: several NSAIDs can reduce pain and inflammation.
5. Topical treatment: localized soft-tissue injury or osteoarthritis pain.

Evidence also supports topical NSAIDs for some localized conditions, especially when the goal is to limit systemic exposure. For older adults or people at higher risk of stomach side effects, topical options may be useful for selected problems.

Choice of NSAID depends on the condition, the person's age, ulcer history, kidney function, cardiovascular risk, other medicines, and whether treatment is short or long term. For example, ketorolac is effective for acute pain but is generally restricted to short-term use because of toxicity risk. Aspirin is not usually the first choice for routine pain relief when other NSAIDs are suitable, because its antiplatelet effect increases bleeding risk.

Safety and interactions

The main risks of NSAIDs are gastrointestinal bleeding or ulcers, kidney injury, fluid retention, worsening blood pressure control, and cardiovascular events such as heart attack or stroke in susceptible people. Risk rises with higher doses, longer duration, older age, prior ulcer or bleeding, dehydration, and use of more than one NSAID at the same time.

Important interaction patterns include:

Combination	Why it matters
NSAID + anticoagulant or antiplatelet	Higher bleeding risk
NSAID + steroid	Higher ulcer and bleeding risk
NSAID + SSRI/SNRI	Bleeding risk may increase
NSAID + ACE inhibitor/ARB + diuretic	Can raise risk of acute kidney injury
NSAID + lithium or methotrexate	Can increase drug levels and toxicity

People with chronic kidney disease, heart failure, uncontrolled hypertension, prior peptic ulcer disease, or established cardiovascular disease need extra caution. NSAIDs can also trigger bronchospasm in some people with aspirin-sensitive asthma. During pregnancy, especially later pregnancy, NSAIDs may be unsafe and should only be used on medical advice.

Practical safety points:

• Use the lowest effective dose for the shortest necessary time.
• Do not combine two oral NSAIDs unless a clinician specifically advises it.
• Check labels, because cold-and-flu or pain products may already contain an NSAID.
• Seek urgent care for black stools, vomiting blood, severe stomach pain, chest pain, sudden weakness, reduced urine, facial swelling, or trouble breathing.

If you need frequent NSAID use, talk to a clinician or pharmacist rather than continuing self-treatment.

When to see a clinician

See a clinician if pain lasts more than a few days, keeps returning, or needs repeated NSAID use. Medical review is also sensible before using NSAIDs if you are older, have kidney disease, heart disease, high blood pressure, liver disease, asthma triggered by painkillers, or a history of ulcers or gastrointestinal bleeding.

Get prompt advice if you are pregnant, breastfeeding, taking blood thinners, taking steroids, or using medicines for blood pressure, lithium, or methotrexate. In children, dosing and product choice should be age-appropriate, and aspirin should generally be avoided because of the risk of Reye syndrome.

Limitations and open questions

NSAIDs are effective symptom relievers, but they do not treat every cause of pain and they do not reverse most chronic pain disorders. Response varies between people, and a drug that works well for one person may not be the best choice for another because of side effects or comorbidities.

Evidence is strong for many short-term uses, but the safest long-term strategy remains individualized. Researchers continue to study how different NSAIDs compare for cardiovascular risk, kidney effects, and gastrointestinal safety in real-world populations, especially older adults and people taking multiple medicines. Another practical limitation is non-medical or extra-medical use, including self-medication and dose escalation, which can increase harm without improving outcomes.

For readers in India and elsewhere, the biggest gap is often not lack of access but lack of medication review. Because many NSAIDs are easy to obtain, people may not realize that common painkillers can interact with prescription medicines or worsen kidney, stomach, or heart problems. A clinician or pharmacist can help choose a safer option and decide when another diagnosis or treatment is needed.