Naprosyn 500 mg Tablets

Brand Name

The medication is marketed under the brand name Naprosyn, a widely acknowledged label in the realm of pain relief and anti-inflammatory therapy.

International Nonproprietary Name (INN)

The active ingredient in this product is identified globally as naproxen, a name standardized for consistency across international pharmacological practices.

Form of Release

Naprosyn is available in several forms, including oral tablets, enteric-coated tablets, and suspension. Tablets come in strengths of 250 mg, 375 mg, and 500 mg, while the suspension offers 125 mg per 5 mL, providing flexible dosing options for various patient needs.

Composition

Each tablet of Naprosyn contains naproxen as the primary active substance, with dosages varying by strength (250 mg, 375 mg, or 500 mg). The formulation includes several inactive ingredients, such as microcrystalline cellulose, which provides structural integrity, and lactose monohydrate, acting as a filler. Additional excipients like magnesium stearate serve as lubricants, while povidone aids in binding. The enteric-coated version includes methacrylic acid copolymer for gastric protection, and the suspension contains sorbitol and methylparaben as sweeteners and preservatives. These components ensure effective delivery and stability across all forms.

Pharmacologic Properties

Pharmacodynamics

Naprosyn belongs to the nonsteroidal anti-inflammatory drug (NSAID) class, exerting its effects by inhibiting cyclooxygenase (COX) enzymes, specifically COX-1 and COX-2. This inhibition reduces prostaglandin synthesis, lipid mediators that drive inflammation, pain, and fever. By lowering prostaglandin levels, the medication alleviates swelling, tenderness, and discomfort in affected tissues, while its antipyretic action helps normalize elevated body temperature. Its balanced COX inhibition provides robust analgesia and anti-inflammatory benefits with a moderate gastrointestinal risk profile compared to non-selective NSAIDs.

The drug’s action extends to peripheral tissues and the central nervous system, where it modulates pain perception. Clinical studies demonstrate its efficacy in reducing pain intensity by 50% or more within 1–2 hours in conditions like arthritis or dysmenorrhea. It does not alter disease progression in chronic conditions but offers symptomatic relief, improving quality of life. This mechanism underpins its versatility in managing acute and chronic inflammatory states.

Pharmacokinetics

Following oral administration, Naprosyn is absorbed efficiently from the gastrointestinal tract, with peak plasma concentrations reached within 2 to 4 hours for standard tablets and 4 to 6 hours for enteric-coated forms. Bioavailability approaches 95%, enhanced by food intake, which delays but does not reduce absorption. The drug binds extensively to plasma proteins, primarily albumin, at over 99%, concentrating its distribution in the bloodstream and inflamed tissues.

Metabolism occurs in the liver via cytochrome P450 enzyme CYP2C9, converting naproxen into 6-O-desmethylnaproxen, an inactive metabolite. The half-life ranges from 12 to 17 hours, supporting twice-daily dosing. Elimination is predominantly renal, with approximately 70% of the dose excreted in urine as metabolites and 10% unchanged, while the remainder exits via bile. This prolonged half-life ensures sustained therapeutic levels with consistent administration.

Indications for Use

Naprosyn is prescribed for a variety of painful and inflammatory conditions in adults and children. It is indicated for rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis, where it reduces joint stiffness, swelling, and pain, enhancing mobility. The medication is also used for acute musculoskeletal disorders, such as sprains or strains, and for postoperative pain following minor procedures.

Other applications include primary dysmenorrhea, offering relief from menstrual cramps, and acute gout attacks, where it curbs inflammation and pain in affected joints. It serves as an antipyretic in fever management and is effective for mild to moderate pain, like headaches or dental discomfort. These diverse uses highlight its role as a versatile NSAID across acute and chronic scenarios.

Contraindications

Naprosyn is contraindicated in patients with a history of hypersensitivity to naproxen or other NSAIDs, where reactions could range from mild rashes to severe anaphylaxis or asthma exacerbation. It is also prohibited in those with active peptic ulcer disease, gastrointestinal bleeding, or perforation, due to its potential to worsen these conditions.

Severe heart failure, uncontrolled hypertension, or a history of myocardial infarction preclude its use, given its cardiovascular risks. Patients with severe renal impairment (creatinine clearance below 30 mL/min) or advanced liver disease should avoid it, as should those with a history of NSAID-induced gastrointestinal complications. Use in the third trimester of pregnancy or during coronary artery bypass graft (CABG) surgery recovery is restricted due to fetal and bleeding risks.

Method of Administration and Dosage

Administration Guidelines

The tablets should be taken orally, swallowed whole with water, preferably with food or milk to minimize gastric irritation. Enteric-coated tablets should not be crushed or split to preserve their protective layer, and the suspension requires shaking before measuring with a provided device. Timing with meals enhances tolerability, especially for long-term use.

Dosage for Adults and Children

For adults with arthritis, the typical dose of Naprosyn is 250 mg to 500 mg twice daily, with a maximum of 1,500 mg daily for short-term use. Acute pain or dysmenorrhea uses 500 mg initially, followed by 250 mg every 6–8 hours, up to 1,250 mg daily. Gout treatment starts at 750 mg, then 250 mg every 8 hours until resolution. Children over 2 years with juvenile arthritis receive 10–15 mg/kg daily in two divided doses, capped at adult limits. Younger children or those under 2 are not typically prescribed this therapy.

Dose Adjustment in Specific Conditions

In mild to moderate renal impairment (creatinine clearance 30–60 mL/min), lower doses are advised, while severe impairment contraindicates use. Mild to moderate liver dysfunction requires caution and possible reduction, with severe cases prohibiting administration. Elderly patients or those with gastrointestinal sensitivity may start at 250 mg daily, adjusted based on tolerance. Pain management allows flexible dosing, but total daily intake should not exceed recommended limits.

Side Effects

Naprosyn may trigger a range of side effects, though many patients experience only mild reactions with proper use. Common issues include gastrointestinal discomfort, such as dyspepsia, nausea, or heartburn, often mitigated by food co-administration. Drowsiness, headache, or dizziness are also reported, typically resolving without intervention.

Less frequent effects include fluid retention, mild hypertension, or tinnitus, reflecting systemic prostaglandin inhibition. Rare but serious reactions, such as gastrointestinal bleeding, renal impairment, or cardiovascular events (e.g., myocardial infarction), require immediate cessation and medical attention, particularly in high-risk groups. Skin rashes or bronchospasm may occur in sensitive individuals. Monitoring during long-term use helps manage these risks effectively.

Overdose

Symptoms of Overdose

Excessive intake of Naprosyn may lead to nausea, vomiting, abdominal pain, and drowsiness, with higher doses causing lethargy, seizures, or renal dysfunction. Gastrointestinal bleeding or metabolic acidosis are rare but possible, reflecting exaggerated NSAID effects. Symptoms typically peak within hours and subside with supportive care.

First Aid Measures

In case of overdose, medical consultation is advised, with activated charcoal considered within 1–2 hours of ingestion to limit absorption. Treatment focuses on supportive care, such as hydration for renal protection or antacids for gastric distress. Monitoring vital signs and kidney function is key until recovery, usually within 24–48 hours, given the drug’s half-life.

Drug Interactions

Effects on Other Medications

Naprosyn inhibits CYP2C9 to a mild extent, potentially increasing levels of warfarin, heightening bleeding risk, or phenytoin, requiring dose adjustments. It may reduce the efficacy of antihypertensives like ACE inhibitors or beta-blockers by counteracting prostaglandin-mediated vasodilation. Co-use with other NSAIDs or corticosteroids amplifies gastrointestinal and renal risks, necessitating caution.

Lithium levels may rise due to reduced renal clearance, and methotrexate toxicity could increase with concurrent use. Patients should space administration of antacids or cholestyramine, which may bind the drug and reduce absorption, by 1–2 hours.

Compatibility with Alcohol and Food

Moderate alcohol use does not directly alter efficacy but may increase gastrointestinal irritation risk, suggesting limited intake during therapy. Food enhances absorption and tolerability, making it a recommended co-administration strategy, though it may slightly delay onset.

Special Precautions

Use During Pregnancy and Breastfeeding

Naprosyn is Category C in the first two trimesters, with use limited to cases where benefits outweigh risks, and contraindicated in the third trimester due to risks of premature ductus arteriosus closure and prolonged labor. It passes into breast milk in small amounts, so breastfeeding mothers should avoid it or interrupt nursing during short-term use, guided by medical advice.

Women of childbearing age should use contraception during therapy and confirm non-pregnant status before starting long-term regimens.

Impact on Driving and Operating Machinery

The medication may cause drowsiness or dizziness in some patients, suggesting caution with driving or machinery until tolerance is clear. Most individuals resume normal activities once adjusted, but initial doses warrant observation for sedative effects.

Considerations for Elderly and Pediatric Populations

Elderly patients tolerate Naprosyn well at lower doses, though renal and gastrointestinal monitoring is critical due to age-related risks. Children over 2 with juvenile arthritis can use it safely with weight-based dosing, while those under 2 lack established safety data, limiting use to older pediatric groups.