Naproxen Tablets

What is Naproxen?

Naproxen is a Non‑Steroidal Anti‑Inflammatory Drug (NSAID) that reduces pain, swelling, redness and fever. It works by blocking the production of prostaglandins – chemicals in the body that cause inflammation and pain.

Active Ingredient and Drug Class

The active ingredient is naproxen, a propionic acid derivative NSAID. It has analgesic, anti‑inflammatory and antipyretic properties.

Mechanism of Action with Patient-Friendly Analogies

Think of inflammation as a fire alarm that keeps ringing. Prostaglandins are the "alarm signals" that tell your body to feel pain and swelling. Naproxen acts like a mute button – it stops the production of these alarm signals, so the pain and inflammation calm down.

More specifically, Naproxen works by:

1. Inhibiting the cyclooxygenase (COX‑1 and COX‑2) enzymes
2. Reducing the synthesis of prostaglandins from arachidonic acid
3. Decreasing pain perception at nerve endings
4. Lowering local blood flow and swelling at inflamed sites

Biological Pathway Explanation

In inflamed tissues, phospholipase A2 releases arachidonic acid from cell membranes. Cyclooxygenase enzymes convert arachidonic acid into prostaglandin H2, which is then transformed into various prostaglandins (PGE2, PGI2) and thromboxane A2. Naproxen reversibly inhibits both COX‑1 (constitutive, protecting stomach lining) and COX‑2 (induced in inflammation), thereby reducing prostaglandin levels and alleviating pain, fever and inflammation.

What is Naproxen Used For?

Naproxen is used to treat a variety of painful and inflammatory conditions in adults and children over 5 years.

Approved Indications

Before Using Naproxen

Before starting Naproxen, tell your doctor about all your medical conditions, especially:

• Asthma, hayfever, nasal polyps or previous allergic reactions to NSAIDs/aspirin
• History of stomach ulcers, bleeding or inflammatory bowel disease (Crohn’s, ulcerative colitis)
• Heart problems, high blood pressure, high cholesterol or previous stroke
• Kidney or liver disease
• Bleeding disorder or taking anticoagulants
• Systemic lupus erythematosus (SLE)
• Chickenpox or shingles (risk of severe skin reactions)
• Elderly (increased risk of serious side effects)

Naproxen Contraindications

Absolute Contraindications (Do Not Use)

• Allergy to naproxen, aspirin, or any other NSAID (ibuprofen, diclofenac)
• Active or recurrent peptic ulcer / gastrointestinal bleeding
• History of GI bleeding or perforation related to previous NSAID use
• Severe heart failure (NYHA class III‑IV)
• Severe liver failure or active liver disease
• Severe renal impairment (eGFR <30 ml/min)
• Last trimester of pregnancy

Relative Contraindications (Use with Extreme Caution)

• Uncontrolled hypertension
• Ischaemic heart disease or cerebrovascular disease
• Risk factors for cardiovascular disease (diabetes, hyperlipidaemia, smoking)
• Systemic lupus erythematosus (risk of aseptic meningitis)
• Bleeding diathesis
• Concurrent use of anticoagulants (warfarin, apixaban) or antiplatelets (clopidogrel)

Special Population Considerations

Elderly Patients (65+ years)

Elderly patients are at higher risk of serious GI events (bleeding, perforation), renal impairment, cardiovascular events and confusion. Use the lowest effective dose for the shortest duration. Monitor blood pressure, renal function and signs of GI bleeding.

Children

Naproxen is approved for children over 5 years with juvenile rheumatoid arthritis. Dose is weight‑based (10 mg/kg/day in two divided doses). Not recommended for acute pain in children unless prescribed by a specialist.

Renal or Hepatic Impairment

Reduce dose and monitor renal/hepatic function. Avoid in severe impairment. Stay well hydrated during treatment.

Naproxen and Other Medicines

Naproxen can interact with many drugs. Always inform your doctor about all medications you take.

High‑Risk Combinations

Pregnancy & Breastfeeding

Pregnancy

Do not take Naproxen during the last 3 months of pregnancy – it can harm your unborn baby’s heart and kidneys. During the first 6 months, use only if absolutely necessary and prescribed by a doctor, at the lowest effective dose for the shortest time. If used for more than a few days after 20 weeks, your baby may develop kidney problems (low amniotic fluid) or a heart vessel narrowing. Additional monitoring may be required.

Breastfeeding

Naproxen passes into breast milk in small amounts. It is generally considered compatible with breastfeeding at standard doses. To minimise exposure, take immediately after a feed. Monitor infant for unusual drowsiness or poor feeding.

Fertility

Naproxen may impair female fertility and is not recommended in women trying to conceive. The effect is reversible after stopping treatment.

Driving & Machine Operation

Naproxen may cause dizziness, drowsiness, fatigue, visual disturbances or vertigo. If you experience any of these, do not drive or operate machinery. Alcohol can worsen these effects.

Naproxen Ingredients

Active Ingredient

• Naproxen 250mg or 500mg per tablet

Excipients (Inactive Ingredients)

• Lactose monohydrate (contains milk sugar – avoid if lactose intolerant)
• Maize starch
• Povidone
• Sodium starch glycollate
• Magnesium stearate
• Yellow lake CLF 3076 (contains E104 quinoline yellow aluminium lake and E172 iron oxide)

How to Use Naproxen

1. Swallow the tablet whole with a full glass of water.
2. Take with or after food to reduce stomach upset.
3. Do not crush, chew or break the tablet.
4. Take at the same time(s) each day – usually every 12 hours.
5. Stay well hydrated while taking Naproxen, especially if you have kidney problems.

Naproxen Dosage Guidelines

Elderly or renal/hepatic impairment: Lower doses recommended (e.g., 250mg twice daily). Use shortest duration possible.

Administration Instructions

• With food/milk: Reduces GI irritation.
• Evenly spaced: Take every 12 hours for arthritis; for acute pain, every 6‑8 hours as needed.
• Avoid alcohol: Increases risk of stomach bleeding.
• Do not take with other NSAIDs (ibuprofen, aspirin, diclofenac).

Missed Dose Management

If you forget a dose, skip the missed dose and take your next dose at the usual time. Do not take a double dose to make up for a forgotten one.

Overdose Information

Symptoms of overdose include nausea, vomiting, stomach pain, drowsiness, dizziness, headache, ringing in ears, and rarely seizures or kidney failure. If you take too many tablets, contact your doctor or go to A&E immediately. Take the medicine pack with you.

Naproxen Side Effects

How to Store Naproxen

Store below 25°C in the original package. Keep out of sight and reach of children. Do not use after expiry date. Return unused tablets to pharmacy for disposal.

Naproxen Pack Information

Naproxen 250mg tablets: yellow, circular, marked "NXN 250" with breakline on one face and "CP" on reverse. Naproxen 500mg tablets: yellow, capsule‑shaped, marked "NXN 500" with breakline. Available in blister packs of 28 tablets.

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