NX-1 (Naproxen)

NX-1 (Naproxen)

Description

Naproxen is a nonsteroidal anti-inflammatory drug with analgesic and antipyretic properties. Naproxen works by reducing the levels of prostaglandins, chemicals that are responsible for pain, fever and inflammation. Naproxen blocks the enzyme that makes prostaglandins (cyclooxygenase), resulting in lower concentrations of prostaglandins. As a consequence, inflammation, pain and fever are reduced.

 Indications and Uses

Naproxen is indicated for its anti-inflammatory and analgesic action in the treatment of rheumatoid arthritis, osteoarthritis (degenerative arthritis), ankylosing spondylitis, juvenile rheumatoid arthritis, acute gout, acute musculoskeletal disorders, post-operative pain and dysmenorrhoea. It is also indicated in the relief of mild to moderate pain, and for the treatment of tendonitis and bursitis.

Dosage and administration

Adults

For rheumatoid arthritis, osteoarthritis and ankylosing spondylitis

The usual dose is 500-1000 mg per day taken in 2 doses at 12 hours intervals after meals.

For acute gout

750 mg should be given initially, followed in 8 hours with 500 mg, and thereafter 250 mg at 12 hours intervals until the attack has passed.

For dysmennorhoea

500 mg should be given initially, followed by 250 mg at 6-8 hour intervals for up to 5 days.

For analgesia and acute muscular skeletal disorders

500 mg should be given initially, followed by 250 mg at 6-8 hour intervals.

Children over 5 years

For juvenile rheumatoid arthritis

10mg/kg/day given as 2 divided doses at 12 hour intervals.

 Contraindications

The drug is contraindicated in patients who have had allergic reactions to Naproxen. It is also contraindicated in patients in whom aspirin or other nonsteroidal anti-inflammatory/analgesic drugs induce the syndrome of asthma, rhinitis, and nasal polyps. Both types of reactions have the potential of being fatal.

 Precautions

Serious GI toxicity such as bleeding, ulceration, and perforation, can occur at any time, with or without warning symptoms, in patients treated chronically with NSAID therapy. Although minor upper GI problems, such as dyspepsia, are common, usually developing early in therapy, physicians should remain alert for ulcerations and bleeding in patients treated chronically with NSAIDs even in the absence of previous GI tract symptoms.

 Side-effects

The most common side effects from Naproxen are rash, ringing in the ears, headaches, dizziness, drowsiness, abdominal pain, nausea, diarrhea, constipation, heartburn, fluid retention and shortness of breath. Naproxen also may cause stomach and intestinal bleeding and ulcers.

 Use in pregnancy and lactation

Pregnancy: Pregnancy Category C.

Naproxen should be used during pregnancy only if the potential benefits justify the potential risks to the fetus.

Nursing mother: The Naproxen has been found in the milk of lactating women. Because of the possible adverse effects of prostaglandin-inhibiting drugs on neonates, use in nursing mothers should be avoided.

 Drug interactions

Naproxen may increase the blood levels of lithium by reducing the excretion of lithium by the kidneys. Increased levels of lithium may lead to lithium toxicity.

Naproxen may reduce the blood pressure lowering effects of blood pressure medications.

When naproxen is used in combination with aminoglycosides (e.g., gentamicin) the blood levels of the aminoglycoside may increase. This may lead to more aminoglycoside-related side effects.

Individuals taking anticoagulants (e.g. Warfarin) should avoid naproxen because naproxen also thins the blood, and excessive blood thinning may lead to bleeding.