Pharma Jogot
Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain, menstrual cramps, and inflammatory diseases such as rheumatoid arthritis, gout, and fever. It is taken orally. It is available in immediate and delayed-release formulations. The onset of effects is within an hour and lasts for up to twelve hours.
Naproxen was patented in 1967 and approved for medical use in the United States in 1976. In the United States, it is available over the counter and as a generic medication. In 2020, it was the 91st most commonly prescribed medication in the United States, with more than 8 million prescriptions.
Indications
Naproxen is indicated for the relief of signs and symptoms of rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, juvenile arthritis, tendonitis, bursitis, acute gout, etc.
It is also indicated for the management of primary dysmenorrhea & pain.
Pharmacology
As with other non-selective NSAIDs, naproxen exerts its clinical effects by blocking COX-1 and COX-2 enzymes leading to decreased prostaglandin synthesis. Although both enzymes contribute to prostaglandin production, they have unique functional differences. The COX-1 enzyme is constitutively active and can be found in normal tissues such as the stomach lining, 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.
Dosage & Administration
Naproxen Tablet-
- Rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis: The usual dose is 500-1000 mg daily in two divided doses after meals.
- Management of pain, primary dysmenorrhea, acute tendonitis & bursitis: The recommended starting dose is 500 mg followed by 500 mg every 12 hours or 250 mg every 6-8 hours. The initial total daily dose should not exceed 1250 mg and thereafter, the total daily dose should not exceed 1000 mg.
- Acute gout: Recommended starting dose is 750 mg followed by 250 mg every 8 hours until the attack has subsided.
Naproxen Suspension-
- For Juvenile rheumatoid arthritis: The usual dose for children over 2 years is 10 mg/kg/day given as two divided doses at 12-hour intervals. Therapy in children under 2 years of age is not recommended.
Naproxen Gel-
- Is to be applied 2-6 times a day as required and is not recommended for use in children.
Interaction
ACE inhibitors: Diminish the antihypertensive effect of ACE inhibitors.
Antacids & Sucralfate: Delays the absorption of Naproxen.
Aspirin: Increases adverse effects.
Diuretics: Reduce the natriuretic effect of Furosemide and Thiazides.
Methotrexate: Enhance the toxicity of Methotrexate.
Warfarin: Increases the risk of GI bleeding.
Selective Serotonin Reuptake Inhibitors (SSRI): Increase the risk of GI bleeding.
Contraindications
Naproxen is contraindicated in patients with known hypersensitivity to Naproxen. It should not be given to patients who have experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs. It is contraindicated for the treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
Side Effects
The most frequently reported side effects include the following:
- Gastrointestinal: Heartburn, abdominal pain, nausea, diarrhea, dyspepsia.
- Central Nervous System: Headache, vertigo, drowsiness.
- Dermatological: Pruritus (itching), purpura.
- Cardiovascular: Edema, palpitation.
- Others: Visual disturbances, hearing disturbances.
Pregnancy & Lactation
Most non-steroidal anti-inflammatory drugs may harm the fetus through their pharmacological properties. Naproxen causes a delay in parturition in animals and has been associated with premature closure of the ductus arteriosus and severe pulmonary hypertension in infants born to mothers taking Naproxen. The use of Naproxen in the first and third trimesters requires careful balancing of the benefits to the mother against the possible risks to the fetus. Naproxen is excreted in small amounts in the breast milk of nursing mothers. The amount of Naproxen distributed into breast milk is considered by some authorities to be too small to be harmful to a breastfed infant although some manufacturers recommend that breastfeeding should be avoided during Naproxen therapy.
Precautions & Warnings
Renal effects: As with other non-steroidal anti-inflammatory drugs, long-term administration of naproxen to animals has resulted in renal papillary necrosis and other abnormal renal pathology. In humans, there have been reports of acute interstitial nephritis, hematuria, proteinuria, and occasionally nephrotic syndrome associated with Naproxen-containing products and other NSAIDs since they have been marketed. Naproxen and its metabolites are eliminated primarily by the kidneys; therefore, the drug should be used with caution in patients with significantly impaired renal function, and the monitoring of serum creatinine and/or creatinine clearance is advised in these patients. Caution should be used if the drug is given to patients with creatinine clearance of less than 20ml/min because accumulation of naproxen metabolites has been seen in such patients.
Hepatic effects: There have been a few reports of moderate to severe jaundice attributed to Naproxen.
Storage Conditions
- Store in a cool & dry place below 30°C.
- Protect from light & moisture.
- Keep out of reach of children.
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