NAPRO

Each uncoated tablet contains:

(Naproxen BP   250 mg / 500 mg )

Tablet for Oral Use

Naproxen exerts its clinical effects by blocking COX-1 and COX-2 enzymes leading to decreased prostaglandin synthesis.  COX-1 is constitutively expressed in most tissues, while COX-2 is only expressed in the brain, kidney, bones, reproductive organs, and select tumors such as colon and prostate cancers. COX-1 is responsible for prostaglandin synthesis in response to stimulation by circulating hormones and maintaining healthy renal function, gastric mucosal integrity, and hemostasis while the COX-2 enzyme is inducible and produces prostaglandins that mediate pain, fever and inflammation. The COX-2 enzyme mediates the desired antipyretic, analgesic and anti-inflammatory properties offered by Naproxen, while undesired adverse effects such as gastrointestinal upset and renal toxicities are linked to the COX-1 enzyme.

Absorption: Peak plasma concentration is observed after 2 hours with naproxen (free acid).Naproxen is rapidly and completely absorbed when administered orally and rectally. Food may contribute to a delay in the absorption of orally administered naproxen, but will not affect the extent of absorption.

Distribution: Naproxen has a volume of distribution of 0.16 L/kg.

Plasma Binding: Naproxen is highly protein bound with >99% of the drug bound to albumin at therapeutic levels.

Metabolism &Excretion: Naproxen is heavily metabolized in the liver. About 95% of Naproxen and its metabolites can be recovered in the urine with 66-92% recovered as conjugated metabolite. Less than 5% of Naproxen is excreted in the feces

Half Life: The elimination half-life of naproxen is reported to be 12-17 hours.

• Mild to Moderate Arthritis (osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis): 220 to 550 mg PO every 12 hours

Acute Gouty Arthritis: 750 mg initial dose followed by 275 mg PO every 8 hours until symptom resolution

Acute Severe Headache or Migraine: 550 mg every 12 hours; can increase the dosage to 825mg PO if needed; do not exceed the max of 1375 mg daily.

Maximum Recommended Daily Doses for Children

• 12 years and older – 20 mg/kg/day by mouth, not to exceed 1000 mg/day by mouth; for non-prescription use, 660 mg/day by mouth
• 2 to 12 years – 20 mg/kg/day by mouth, not to exceed 1000 mg/day by mouth. Non-prescription use is not recommended
• Less than 2 years – Safety and efficacy not established

ADVERSE REACTION: Dyspepsia, nausea, dizziness, elevated liver enzymes, increased blood pressure, diminished renal function, rash, increased bleeding risk, and GI ulcers.

CONTRAINDICATIONS:  Hypersensitivity to NSAID medications, NSAID-induced asthma, Pregnancy (caution against use in 1st trimester, absolute contraindication at 30 weeks gestation), Perioperative use for coronary artery bypass graft surgery (CABG)

WARNINGS AND PRECAUTIONS:

• Avoid drinking alcohol, it may increase your risk of stomach bleeding.
• It may not be safe to breastfeed while using naproxen.
• Prolonged use may increase risk of adverse cardiovascular events May cause new-onset of hypertension; monitor blood pressure closely throughout therapy
• Over-the-counter (OTC) use not for children under 12 years of age

Drug Interaction:  Serious Interaction includes ACE inhibitors, ARBs, Methotrexate, Tacrolimus etc. Naproxen has moderate interactions with at least 229 different drugs. Naproxen has mild interactions with at least 80 different drugs.