Naproxen

Naproxen(:中文 萘普生)is an anti-steroidal anti inflammatory drug, an NSAID. As an NSAID, indomethacin is an analgesic, anti-inflammatory and antipyretic. Clinical indications for naproxen include: Musculoskeletal and joint disorders

• rheumatoid arthritis
• alkylosing spondylitis
• osteoarthritis
• gouty arthritis
• acute painful shoulder bursitis or tendinitis

It is also be used in menstrual pain, headaches, dental pain, postoperative and postpartum pain.

Pronunciation

Naproxen 250mg

Drug name

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Naproxen Sodium Tablet 275mg	NAPR01	P1S1S3

Mechanism of Action

Non-opioid Analgesic (NSAID) Anti-inflammatory agent, Nonselective COX inhibitor, inhibits COX-1 and COX-2 with relative equipotency

Dosage

Rheumatic disorders	Oral : 500 mg to 1 g daily either as a single dose or in 2 divided doses.
Acute gout	Oral : initial dose 750 mg followed by 250 mg every 8 hours
Dysmenorrhea	Oral : initially 500 mg, followed by 250 mg every 6 to 8 hours, up to a maximum daily dose of 1.25 g on the first day and 1 g thereafter.
Acute musculoskeletal disorders	Oral : initially 500 mg, followed by 250 mg every 6 to 8 hours, up to a maximum daily dose of 1.25 g on the first day and 1 g thereafter.

Naproxen has been given rectally in similar doses to those used orally.

Administration in children

Juvenile idiopathic arthritis (2 years and over)	Oral: 10 mg/kg daily in 2 divided doses.
Musculoskeletal disorders	Oral: 5 mg/kg twice daily (maximum of 1 g daily).

Side Effects

NSAIDs in genera

Common side effects	heartburn, nausea, dyspepsia, diarrhea, constipation, gastrointestinal ulceration/bleeding, headache, dizziness, rash, salt and fluid retention, and high blood pressure.

Naproxen suppositories can cause rectal irritation and occasional bleeding.

Naproxen should be used with caution in renal impairment, and use is not recommended in patients whose creatinine clearance is less than 20 mL/min.

blood	localized spontaneous bleeding, bruising and prolonged bleeding time have been reported
Asthma	Can be worsen
Cardiovascular risk	Chronic ibuprofen use has been found correlated with risk of progression to hypertension and myocardial infarction (heart attack). Both the U.S. Food and Drug Administration (FDA) and The European Medicines Agency (EMA) issues warnings of increased heart attack and stroke risk.
Skin	NSAIDs have been associated with the onset of bullous pemphigoid. It can also cause serious skin adverse events such as exfoliative dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis, which can be fatal.
Muscle cramps	Naproxen may cause muscle cramps in the legs in 3% of people
Stomach ulcers	Naproxen poses an intermediate risk of stomach ulcers compared with ibuprofen, which is low-risk, and indomethacin which is high-risk

It also increases the risk of heart attack, stroke, kidney failure and liver failure.

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Pharmacokinetics

Naproxen and naproxen sodium are readily absorbed from the gastrointestinal tract. Peak plasma concentrations occur about 1 to 2 hours after ingestion of naproxen sodium and about 2 to 4 hours after ingestion of naproxen.

At therapeutic concentrations it is more than 99% bound to plasma proteins.

Diclofenac penetrates synovial fluid; it crosses the placenta and small amounts are distributed into breast milk.

Naproxen has a plasma elimination half-life of about 12 to 17 hours.

It is excreted mainly in the urine (about 95%). Less than 5% of a dose appears in the faeces.

Drug Management

Efficiency

Pain and inflammation control

Safety

Monitor signs of bleeding and bruising, and blood pressure.

Drug Interaction

Interactions involving NSAIDs include

• enhancement of the effects of oral anticoagulants
• increased plasma concentrations of lithium, methotrexate and cardiac glycosides.
• Risk of nephrotoxicity may be increased if given with ACE inhibitors, ciclosporin, tacrolimus or diuretics
• Antihypertensive effects of ACEIs, beta blockers and diuretics may be reduced
• Use of more than one NSAID together (including aspirin) should be avoided because of the increased risk of adverse effects.
• The risk of gastrointestinal bleeding and ulceration is increased when used with steroids, the SSRIs, the SNRI venlafaxaine, the antiplatelet clopidogrel, bisphosphonates or pentoxifylline.
• Co-administration of ACE inhibitor can increase risk of kidney problem and increase hypotensive effect.
• Aspirin.

Precaution

There has been a report of a patient with Parkinson’s disease whose symptoms had previously been well controlled but who deteriorated when she was given naproxen.

Caution

• Allergic reaction,
• Previous peptic ulcer
• uncontrolled hypertension,
• Impaired renal function

Contraindication

• Hypersensitivity against diclofenac
• History of allergic reactions (bronchospasm, rhinitis, urticaria) following the use of other NSAIDs such as aspirin
• Third-trimester pregnancy
• Active stomach and/or duodenal ulceration or gastrointestinal bleeding
• Inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
• Severe congestive heart failure (NYHA III/IV)
• Severe liver insufficiency
• Severe chronic kidney disease (creatinine clearance <30 mi/min)
• Caution in patients with pre-existing hepatic porphyria, as diclofenac may trigger attacks
• Caution in patients with severe, active bleeding such as cerebral hemorrhage
• Caution in patients with fluid retention or heart failure
• Can lead to onset of new hypertension or worsening of pre-existing hypertension

FAQ

How should I take the tablet?

Follow the doctor's prescription Take with food if diclofenac upsets your stomach.

What should I avoid while taking?

Avoid alcohol consumption.

What happen if I overdose?

Contact your primary care doctor. If emergency situation, call 999

What happen if I miss a dose?

Take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.