PTCB Guide to NSAIDs

Also called Nonsteroidal anti-inflammatory drugs · suffix no single suffix · updated July 15, 2026

What gets tested

• Recognizing common NSAIDs and matching brand to generic (Advil and Motrin are ibuprofen, Aleve is naproxen sodium)
• The COX-1 and COX-2 mechanism and the anti-inflammatory, analgesic, and antipyretic effects
• That most NSAIDs block COX reversibly while aspirin blocks it irreversibly, which is why aspirin alone is used as an antiplatelet drug
• The signature GI side effects (ulcers and bleeding) plus kidney and cardiovascular risks, and that the FDA boxed warning covers both the GI and the cardiovascular risk
• Which NSAID is COX-2 selective (celecoxib), why that matters for the stomach, and that celecoxib is a sulfonamide
• Key interactions: warfarin and other anticoagulants, ACE inhibitors and ARBs, doubling up on NSAIDs, and ibuprofen blunting low-dose aspirin
• That ketorolac (Toradol) is capped at 5 days of total therapy
• The aspirin and Reye's syndrome warning in children and teenagers
• That aspirin is also an antiplatelet drug and that acetaminophen (Tylenol) is not an NSAID

What is not tested

You do not need to memorize dose titration schedules, receptor kinetics, or the biochemistry of the arachidonic acid pathway, and the PTCE will not ask you to make prescribing decisions. Do know the practical limits it does cover, such as ketorolac's 5-day cap and the labeled maximums on OTC packages, because strengths and doses, dosage forms, routes of administration, special handling instructions, and duration of drug therapy are a named PTCE knowledge area.

Why nsaids matter

NSAIDs are among the most widely used medications in the world, sold both over the counter and by prescription, so technicians handle them constantly. They also carry high-yield safety points (a two-part boxed warning for GI bleeding and cardiovascular events, kidney risk, the warfarin interaction, ketorolac's 5-day limit, and the Reye's syndrome warning on aspirin) that appear across the Medications and safety domains.

NSAIDs at a glance

Mechanism of action

NSAIDs inhibit cyclooxygenase (COX), the enzyme that converts arachidonic acid into prostaglandins (along with related thromboxanes and prostacyclins). With fewer prostaglandins, NSAIDs reduce inflammation, relieve pain, and lower fever. There are two forms of the enzyme: COX-1 is present all the time and helps protect the stomach lining, support kidney blood flow, and let platelets clot, while COX-2 is mainly switched on during inflammation. Most NSAIDs (ibuprofen, naproxen, and others) block both COX-1 and COX-2, whereas celecoxib is COX-2 selective, which spares more of the stomach-protecting COX-1. Those NSAIDs also bind COX reversibly, so the block wears off as the drug clears the body. Aspirin is the exception: it irreversibly inactivates COX in all tissues. Because platelets have no nucleus and cannot make new enzyme, one low dose of aspirin shuts down platelet thromboxane for the 7 to 10 day lifespan of the platelet. That is why low-dose aspirin is used as an antiplatelet drug and the other NSAIDs are not. Acetaminophen relieves pain and fever but is not an NSAID and has little anti-inflammatory effect.

Common and important side effects

• Stomach upset, ulcers, and gastrointestinal bleeding or perforation (FDA boxed warning; caused by blocking the protective COX-1 prostaglandins)
• Kidney injury and fluid retention, especially in patients who already have kidney problems
• Higher blood pressure and worsening of heart failure (sodium and water retention)
• Cardiovascular events such as heart attack and stroke (FDA boxed warning, which does not apply to aspirin); diclofenac has the highest reported cardiovascular risk
• Increased bleeding and bruising from reduced platelet function (least with celecoxib, which has little effect on platelets)
• Liver enzyme elevations (uncommon, and highest with diclofenac)
• Allergic and asthma-like reactions in patients with aspirin or NSAID hypersensitivity, particularly asthma with nasal polyps

Key interactions

• Warfarin and other anticoagulants (blood thinners): added bleeding risk, especially in the stomach and intestines
• ACE inhibitors and ARBs: NSAIDs blunt their blood-pressure-lowering effect and, together, raise the risk of kidney injury
• Diuretics: NSAIDs can reduce their fluid-removing effect and promote sodium and water retention
• Other NSAIDs: stacking NSAIDs increases the risk of ulcers and bleeding without added benefit, including OTC cough, cold, and pain products that already contain one
• Low-dose aspirin plus ibuprofen: ibuprofen can block aspirin's antiplatelet effect. Patients taking aspirin for heart protection should take ibuprofen at least 30 minutes after the aspirin, or at least 8 hours before it.
• Corticosteroids and SSRIs or SNRIs: each further increases the risk of gastrointestinal bleeding
• Lithium and methotrexate: NSAIDs can raise the blood levels of these drugs and increase their toxicity

Patient counseling notes

• Take NSAIDs with food or milk to reduce stomach upset (this eases symptoms but does not prevent ulcers)
• Report black or tarry stools, vomit that looks like coffee grounds, or ongoing stomach pain, which can signal GI bleeding
• Watch for swelling, sudden weight gain, or shortness of breath, which can signal fluid retention or heart or kidney problems
• Do not combine more than one NSAID at a time, and check that OTC cough, cold, and pain products do not add another NSAID
• Use the lowest effective dose for the shortest time, and ask the pharmacist first if taking warfarin, a blood pressure medicine, or living with kidney disease
• Do not give aspirin to children or teenagers with a fever, chickenpox, or a flu-like illness: it can cause Reye's syndrome, a rare but life-threatening condition
• Tell the pharmacist about any aspirin or NSAID allergy and about asthma with nasal polyps, since NSAIDs can trigger severe reactions. NSAIDs must also be stopped around coronary artery bypass (CABG) surgery.
• Avoid NSAIDs from about 20 weeks of pregnancy onward unless a doctor directs otherwise. One exception: low-dose 81 mg aspirin may be used at any point in pregnancy when a prescriber directs it.

Practice questions

Then test the whole class in context with the drug class identification quiz and the brand and generic quiz.

Related drug-class guides

Official sources

• StatPearls: Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) (NBK547742)
• StatPearls: Aspirin (NBK519032)
• MedlinePlus: Ibuprofen
• MedlinePlus: Celecoxib
• MedlinePlus: Ketorolac
• DailyMed: Ibuprofen tablet (FDA label, boxed warning)
• FDA: Avoid use of NSAIDs in pregnancy at 20 weeks or later

PTCB Quiz Prep is an independent study resource, not affiliated with the Pharmacy Technician Certification Board. This guide is for exam preparation, not medical advice. See our editorial standards. Part of the PTCB Medications domain.