Dayprox

Approved Indications:

• Osteoarthritis (OA):
  For the relief of signs and symptoms, including joint pain, stiffness, and swelling.
• Rheumatoid Arthritis (RA):
  Indicated for the treatment of moderate to severe RA in adults.
• Juvenile Rheumatoid Arthritis (JRA):
  Approved for use in children aged 6 years and older for the relief of signs and symptoms of JRA.

Clinically Accepted Off-label Uses:

• Ankylosing Spondylitis
• Acute Musculoskeletal Pain
• Gout (Short-term Inflammatory Relief) – As a non-steroidal anti-inflammatory drug (NSAID), oxaprozin may be used to relieve inflammation in acute gout, although it is not a first-line therapy.

Route: Oral
Frequency: Once daily (due to long half-life)
Administer with food or milk to reduce gastrointestinal side effects.

Adults:

• Osteoarthritis and Rheumatoid Arthritis:
• Initial: 1200 mg once daily
• Maintenance: 600–1200 mg once daily depending on response

Pediatrics (Juvenile RA, ≥6 years, weight-based):

• 13–25 kg: 600 mg once daily
• 26–35 kg: 900 mg once daily
• >35 kg: 1200 mg once daily
• Not recommended for children <6 years.

Elderly:

• Start at the lower end of the dose range (e.g., 600 mg/day) due to increased sensitivity to NSAIDs.

Renal Impairment:

• Use with caution. Avoid in patients with severe renal dysfunction (CrCl <30 mL/min).

Hepatic Impairment:

• Use cautiously; monitor liver function periodically. No specific adjustment required in mild-to-moderate impairment.

Oxaprozin is a non-steroidal anti-inflammatory drug (NSAID) that exerts its therapeutic effect by inhibiting cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing the synthesis of prostaglandins, which are mediators of inflammation, pain, and fever. This inhibition leads to analgesic, anti-inflammatory, and antipyretic effects. Its long half-life allows for once-daily dosing.

• Absorption: Well absorbed orally; peak plasma levels reached in 3–5 hours.
• Bioavailability: Approximately 95%
• Distribution: Widely distributed; >99% bound to plasma proteins.
• Metabolism: Extensively metabolized in the liver via CYP enzymes (mainly CYP2C9).
• Half-life: 40–60 hours (supports once-daily dosing)
• Excretion: Primarily renal (urine) as metabolites; ~5% excreted unchanged. Minor fecal elimination.

• Pregnancy:
• FDA Category C (up to 30 weeks gestation) – Use only if clearly needed.
• Category D (from 30 weeks gestation onward) – Contraindicated in third trimester due to risk of premature closure of ductus arteriosus and prolonged labor.
• Lactation:
• Excreted in low amounts in breast milk. Use with caution; monitor infant for GI side effects. Short-term use may be acceptable.

• Primary Class: Non-Steroidal Anti-Inflammatory Drug (NSAID)
• Subclass: Propionic Acid Derivative
• Generation: Long-acting NSAID

• Known hypersensitivity to oxaprozin or other NSAIDs
• History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs
• Active gastrointestinal bleeding or peptic ulcer disease
• Severe renal or hepatic impairment
• Coronary artery bypass graft (CABG) surgery – use is contraindicated in the perioperative period
• Third trimester of pregnancy

• Cardiovascular Risk:
• NSAIDs may increase risk of myocardial infarction and stroke; use at lowest effective dose for shortest duration.
• Gastrointestinal Toxicity:
• Risk of serious GI ulceration, bleeding, and perforation; higher in elderly and with history of ulcers.
• Renal Impairment:
• NSAIDs may impair renal function; caution in dehydration, CHF, or pre-existing kidney disease.
• Hepatic Effects:
• Monitor liver function; discontinue if transaminases elevate persistently or liver injury is suspected.
• Skin Reactions:
• Rare but serious (e.g., Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis); discontinue at first appearance of rash.
• Hematologic Effects:
• Prolonged bleeding time; use caution with anticoagulants or platelet inhibitors.
• Elderly Patients:
• Higher risk of GI bleeding and renal toxicity.

Common (≥1%):

• Gastrointestinal: Dyspepsia, nausea, abdominal pain, constipation, diarrhea
• CNS: Headache, dizziness, drowsiness
• Skin: Rash, pruritus
• Others: Edema, weight gain

Serious or Rare:

• GI ulcer, bleeding, perforation
• Myocardial infarction, stroke
• Acute renal failure
• Hepatitis, jaundice
• Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis
• Aseptic meningitis (especially in lupus patients)

• Anticoagulants/Antiplatelets (e.g., Warfarin, Aspirin): Increased risk of bleeding
• ACE Inhibitors, ARBs, Diuretics: Reduced antihypertensive effect; increased risk of renal toxicity
• Methotrexate: May increase methotrexate toxicity by reducing renal clearance
• Lithium: Increases serum lithium concentration and risk of toxicity
• CYP2C9 Inhibitors/Inducers: May alter oxaprozin metabolism
• Alcohol: Additive GI irritation and ulcer risk

• NSAID-related cardiovascular and GI risks emphasized in FDA and EMA safety updates.
• Lowest effective dose and shortest duration of NSAID therapy now strongly advised in treatment guidelines for OA and RA.
• Combination with proton pump inhibitors (PPIs) recommended in high-risk patients to prevent GI complications.
• Oxaprozin is not recommended as first-line NSAID due to its long half-life and associated delayed clearance in renal impairment.

• Temperature: Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C.
• Humidity: Protect from moisture; keep tightly closed in original container.
• Light Protection: Store away from direct light.
• Handling: No special reconstitution needed. Do not crush or split tablets.