Usage
Oxaprozin is prescribed for the relief of signs and symptoms of osteoarthritis, rheumatoid arthritis, and juvenile rheumatoid arthritis. It is classified as a Non-Steroidal Anti-Inflammatory Drug (NSAID). Oxaprozin works by inhibiting the synthesis of prostaglandins, substances in the body that cause pain and inflammation. It inhibits both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes, which are involved in prostaglandin production.
Alternate Names
While “oxaprozin” is the generic name, some brand names it is marketed under include Daypro, Daypro ALTA (oxaprozin potassium), and Coxanto. There are no widely recognized international or regional variations of the generic name.
How It Works
Pharmacodynamics: Oxaprozin reduces pain and inflammation by inhibiting COX-1 and COX-2 enzymes, thereby decreasing prostaglandin synthesis. It may also inhibit chemotaxis, alter lymphocyte activity, decrease proinflammatory cytokine activity, and inhibit neutrophil aggregation.
Pharmacokinetics:
- Absorption: Oxaprozin is well-absorbed orally (approximately 95%).
- Metabolism: Primarily metabolized in the liver via microsomal oxidation (65%) and glucuronic acid conjugation (35%).
- Elimination: Excreted primarily in urine (65%) and feces (35%). The half-life is approximately 44-50 hours, allowing for once-daily dosing.
- Protein Binding: Highly protein-bound (99%).
- Volume of distribution: 11-17 L/70 kg.
- Time to peak plasma concentration: 2-4 hours.
Mode of Action: Oxaprozin’s primary mechanism is the inhibition of COX-1 and COX-2 enzymes. These enzymes catalyze the formation of prostaglandins from arachidonic acid. By inhibiting these enzymes, oxaprozin reduces the production of prostaglandins, thus mitigating pain and inflammation.
Dosage
Standard Dosage
Adults:
- Osteoarthritis and Rheumatoid Arthritis: 1200 mg orally once daily.
- Loading Dose (for rapid onset): 1200-1800 mg (not to exceed 26 mg/kg) can be administered as a single loading dose.
- Maximum Daily Dose: 1800 mg (or 26 mg/kg, whichever is lower).
Children (Juvenile Rheumatoid Arthritis):
- 6-16 years: Dosage based on body weight:
- 22-31 kg: 600 mg orally once daily.
- 32-54 kg: 900 mg orally once daily.
- ≥55 kg: 1200 mg orally once daily.
- <6 years: Safety and efficacy not established.
Special Cases:
- Elderly Patients: Initiate with a lower dose (e.g., 600 mg/day) due to potential age-related decreases in renal and hepatic function and adjust as needed.
- Patients with Renal Impairment (severe or on dialysis): Initiate with 600 mg orally once daily and increase cautiously to a maximum of 1200 mg/day with close monitoring.
- Patients with Hepatic Dysfunction: Use with caution in severe liver impairment. Dose adjustments may be necessary.
- Patients with Comorbid Conditions: Monitor closely for adverse events, especially cardiovascular and gastrointestinal complications. Dose adjustments may be necessary.
Clinical Use Cases
Oxaprozin is not typically used in clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Other analgesics and anti-inflammatory drugs are generally preferred in these scenarios.
Dosage Adjustments
Dosage adjustments may be required based on patient-specific factors such as renal or hepatic dysfunction, low body weight, and other comorbid conditions. Start with the lowest effective dose and titrate upwards cautiously while monitoring for side effects.
Side Effects
Common Side Effects
Nausea, dyspepsia, abdominal pain, constipation, diarrhea, dizziness, headache, rash, pruritus.
Rare but Serious Side Effects
Gastrointestinal bleeding, ulceration, perforation, myocardial infarction, stroke, Stevens-Johnson Syndrome, toxic epidermal necrolysis, anaphylaxis, renal failure, liver failure, edema, hypertension.
Long-Term Effects
Chronic kidney disease, gastrointestinal ulcers, cardiovascular complications.
Adverse Drug Reactions (ADR)
Gastrointestinal bleeding, anaphylaxis, Stevens-Johnson Syndrome, toxic epidermal necrolysis, acute renal failure, severe hepatic reactions.
Contraindications
Hypersensitivity to oxaprozin or other NSAIDs, history of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs, perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
Drug Interactions
Anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin), selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), diuretics, ACE inhibitors, angiotensin receptor blockers (ARBs), lithium, methotrexate, other NSAIDs. Alcohol can increase the risk of gastrointestinal bleeding.
Pregnancy and Breastfeeding
Pregnancy Category C (first and second trimester) and Category D (third trimester). Oxaprozin should be avoided during the third trimester due to the risk of premature closure of the ductus arteriosus in the fetus. It is not recommended during breastfeeding due to potential excretion in breast milk and potential adverse effects on the neonate.
Drug Profile Summary
- Mechanism of Action: Inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis.
- Side Effects: Nausea, dyspepsia, GI bleeding, MI, stroke.
- Contraindications: Hypersensitivity to oxaprozin, history of aspirin/NSAID-induced asthma/urticaria/allergic reaction, peri-operative CABG pain.
- Drug Interactions: Anticoagulants, antiplatelets, SSRIs, SNRIs.
- Pregnancy & Breastfeeding: Avoid in third trimester and during breastfeeding.
- Dosage: 1200 mg once daily for adults (OA/RA). Adjust dose for children and special populations.
- Monitoring Parameters: Renal function, liver function, complete blood count, blood pressure.
Popular Combinations
Oxaprozin is typically used as monotherapy. Combination with other NSAIDs is generally avoided due to increased risk of adverse effects. Concomitant use with gastroprotective agents (e.g., proton pump inhibitors) may be considered in patients at high risk of gastrointestinal complications.
Precautions
Perform thorough medical history assessment prior to initiating therapy. Use with caution in patients with cardiovascular disease, renal impairment, hepatic dysfunction, history of peptic ulcer disease, and bleeding disorders. Monitor for signs and symptoms of gastrointestinal bleeding, renal toxicity, and cardiovascular events. Advise patients to avoid alcohol and limit sun exposure.
FAQs
Q1: What is the recommended dosage for Oxaprozin?
A: For adults with osteoarthritis or rheumatoid arthritis, the usual dose is 1200 mg orally once daily. For children with juvenile rheumatoid arthritis, dosing is based on body weight (22-31 kg: 600 mg/day, 32-54 kg: 900 mg/day, ≥55 kg: 1200 mg/day). Dosages may need adjustments in elderly patients, patients with renal/hepatic impairment, and other specific patient populations.
Q2: What are the common side effects of Oxaprozin?
A: Common side effects include nausea, dyspepsia, abdominal pain, constipation, diarrhea, dizziness, and headache.
Q3: What are the serious side effects of Oxaprozin?
A: Serious side effects can include gastrointestinal bleeding, ulceration, and perforation; myocardial infarction, stroke; severe skin reactions (Stevens-Johnson Syndrome, toxic epidermal necrolysis); and hypersensitivity reactions.
Q4: Is Oxaprozin safe during pregnancy?
A: Oxaprozin should be avoided during the third trimester of pregnancy. Use during the first and second trimesters should only be considered if the potential benefits outweigh the risks.
Q5: Can Oxaprozin be used in patients with renal impairment?
A: Oxaprozin should be used cautiously in patients with renal impairment. Dose adjustments are often required, with lower initial doses and close monitoring.
Q6: What are the drug interactions of Oxaprozin?
A: Oxaprozin interacts with several medications, including anticoagulants, antiplatelet agents, SSRIs, SNRIs, diuretics, ACE inhibitors, and other NSAIDs.
Q7: What is the mechanism of action of Oxaprozin?
A: Oxaprozin works by inhibiting COX-1 and COX-2 enzymes, which reduces the production of prostaglandins, thus decreasing pain and inflammation.
Q8: What patient education should be provided for Oxaprozin?
A: Counsel patients about the potential side effects, including gastrointestinal and cardiovascular risks. Advise them to report any unusual symptoms immediately, take the medication with food to minimize GI upset, and avoid alcohol. Educate patients about the importance of using the lowest effective dose for the shortest duration necessary.
Q9: How should Oxaprozin be administered?
A: Administer orally once a day, preferably with food or a full glass of water to reduce gastrointestinal irritation. Doses can be divided if necessary for tolerability.
As of today, February 16, 2025, this information is believed to be accurate. However, medical knowledge and guidelines constantly evolve. It’s essential to consult the latest medical references and guidelines for the most up-to-date information before making any clinical decisions.
