What Drugs Are NSAIDs? A Comprehensive Guide

October 13, 2025 •

3 min read

Over 70 million prescriptions are written for nonsteroidal anti-inflammatory drugs (NSAIDs) annually in the United States, with millions more sold over the counter. These widely used medications are effective for reducing pain, fever, and inflammation, but it's crucial to understand what drugs are NSAIDs and how they work.

Quick Summary

A nonsteroidal anti-inflammatory drug is a medication used to reduce pain, fever, and inflammation. These drugs work by inhibiting specific enzymes in the body and are available both over-the-counter and by prescription.

Key Points

Inhibition of COX Enzymes: NSAIDs work by blocking cyclooxygenase (COX) enzymes, which stops the production of pain and inflammation-causing prostaglandins.
Types of NSAIDs: NSAIDs are categorized as either non-selective, inhibiting both COX-1 and COX-2 (e.g., ibuprofen, naproxen), or selective, primarily inhibiting COX-2 (e.g., celecoxib).
Common Uses: These drugs are used to treat a wide range of conditions, including headaches, arthritis pain, menstrual cramps, and fever.
Significant Risks: Potential risks include gastrointestinal issues like ulcers and bleeding, cardiovascular problems such as heart attack and stroke, and kidney damage.
Safe Usage Practices: Always use the lowest effective dose for the shortest time, take with food, and avoid combining different NSAIDs.
Caution Advised: Individuals with pre-existing heart, kidney, or GI conditions, as well as pregnant women and those on blood thinners, should use NSAIDs with caution and medical guidance.

The Core Mechanism of NSAIDs

To understand what drugs are NSAIDs, it helps to know how they function on a molecular level. All NSAIDs work by blocking cyclooxygenase (COX) enzymes, which are responsible for producing prostaglandins. Prostaglandins are hormone-like compounds that cause pain, fever, and inflammation. By inhibiting the COX enzymes, NSAIDs reduce the production of these compounds, providing relief.

There are two primary types of COX enzymes: COX-1 and COX-2.

COX-1: This enzyme is always present in the body and performs important protective functions, such as maintaining the stomach lining and supporting kidney function. Inhibiting COX-1 can lead to gastrointestinal side effects.
COX-2: This enzyme is mainly active at sites of injury or inflammation. Blocking COX-2 provides most of the pain-relieving and anti-inflammatory effects of NSAIDs.

Classifications of NSAIDs

NSAIDs are categorized by their selectivity for COX enzymes, which impacts their side effects.

Non-selective NSAIDs

These inhibit both COX-1 and COX-2 enzymes, effectively reducing pain and inflammation. However, blocking COX-1 increases the risk of stomach irritation and bleeding. Common examples include ibuprofen (Advil, Motrin), naproxen (Aleve), and aspirin. Other non-selective NSAIDs include diclofenac, indomethacin, meloxicam, and ketorolac.

COX-2 Selective Inhibitors (Coxibs)

This class primarily targets COX-2, aiming to reduce gastrointestinal side effects. However, some have been linked to increased cardiovascular risks. Celecoxib (Celebrex) is the main COX-2 selective NSAID currently available.

Therapeutic Uses of NSAIDs

NSAIDs treat various conditions:

Pain Relief: For headaches, menstrual cramps, dental pain, and muscular aches.
Inflammation Reduction: For arthritis, bursitis, and tendinitis.
Fever Reduction: To lower high temperatures.

Risks and Safety Considerations

NSAIDs have potential risks, particularly with long-term use or high doses.

Gastrointestinal Issues: Stomach irritation, ulcers, and bleeding are common, especially with non-selective NSAIDs. Taking them with food can help.
Cardiovascular Risks: Most NSAIDs (excluding low-dose aspirin) carry warnings about increased heart attack and stroke risk, particularly for those with existing heart conditions.
Kidney Problems: NSAIDs can reduce kidney blood flow, potentially causing damage or fluid retention, especially in those with kidney disease.
Pregnancy: Not recommended after 20 weeks due to fetal risks.
Drug Interactions: NSAIDs can interact with blood thinners, certain antidepressants, and blood pressure medications.

Comparison of Common NSAIDs


Feature	Ibuprofen (Advil, Motrin)	Naproxen (Aleve)	Celecoxib (Celebrex)	Aspirin	Diclofenac (Voltaren)
Selectivity	Non-selective	Non-selective	COX-2 selective	Non-selective	Non-selective to low COX-2
Availability	OTC and Prescription	OTC and Prescription	Prescription only	OTC and Prescription	OTC (topical) and Prescription
Duration of Effect	4-6 hours	Up to 12 hours	12 hours (approx.)	4-6 hours	Varies by formulation
Common Uses	Pain, fever, inflammation	Pain, fever, inflammation, longer-lasting arthritis pain	Arthritis, ankylosing spondylitis	Pain, fever, inflammation, cardiovascular protection	Arthritis, topical pain relief
Primary Risk	GI issues, cardiovascular risks	GI issues, cardiovascular risks	Cardiovascular risks	GI issues, bleeding risk (Reye's syndrome in children)	GI issues, cardiovascular risks

How to Use NSAIDs Safely

To minimize risks, follow these guidelines:

Use the lowest effective dose for the shortest duration.
Take with food to protect your stomach.
Avoid combining different NSAID medications.
Consult a doctor before use if taking blood thinners or if you have a history of stomach ulcers, heart disease, or kidney problems.
Check labels, as some cold and flu medications contain NSAIDs.

Conclusion

NSAIDs are effective for managing pain, fever, and inflammation, but their effects and risks vary individually. Understanding what drugs are NSAIDs, their types, and potential side effects is vital for safe use. Always consult a healthcare professional to determine the best treatment for you, especially with pre-existing conditions or other medications.

For more information, refer to the National Institutes of Health guidelines on nonsteroidal anti-inflammatory drugs.

Frequently Asked Questions

NSAIDs reduce pain, fever, and inflammation by blocking the COX enzyme pathway. Acetaminophen is a pain reliever and fever reducer but does not significantly reduce inflammation, and it works through a different mechanism.

Common over-the-counter NSAIDs include ibuprofen (Advil, Motrin), naproxen sodium (Aleve), and aspirin.

You should take NSAIDs with food or milk to help protect the lining of your stomach and reduce the risk of irritation, ulcers, or bleeding.

No, you should not take more than one NSAID at a time. Combining them increases the risk of side effects, especially gastrointestinal issues, without significantly increasing pain relief.

People with a history of stomach ulcers or bleeding, kidney disease, liver disease, heart problems (including recent heart attack or stroke), pregnant women past 20 weeks, and those taking blood thinners should generally avoid NSAIDs.

Serious side effects include gastrointestinal bleeding, stomach ulcers, increased risk of heart attack or stroke (except for low-dose aspirin), and kidney damage.

Yes, some NSAIDs are available as topical creams or gels, such as diclofenac gel (Voltaren). These can provide localized pain relief with a lower risk of systemic side effects.