Naxin Plus375mg + 20mg

Naxin Plus 375mg + 20mg is a fixed-dose combination product containing an NSAID (naproxen) and a proton pump inhibitor (esomeprazole), indicated in adult patients who require ongoing NSAID therapy and are at risk of developing NSAID-associated gastric ulcers.

Established / FDA-approved uses

• Relief of the signs and symptoms of osteoarthritis in patients who require ongoing NSAID therapy and who are at risk of developing NSAID-associated gastric ulcers.
• Relief of the signs and symptoms of rheumatoid arthritis in patients who require ongoing NSAID therapy and who are at risk of developing NSAID-associated gastric ulcers.
• Relief of the signs and symptoms of ankylosing spondylitis in patients who require ongoing NSAID therapy and who are at risk of developing NSAID-associated gastric ulcers.

Naxin Plus 375mg + 20mg is not indicated for the initial treatment of acute pain because the delayed-release naproxen component takes longer to reach peak effect; it is intended for patients who need a stable, longer-term NSAID dosing regimen and are also candidates for prophylaxis against NSAID-induced gastric ulcers.

It is not an appropriate on-demand analgesic and should not be used interchangeably with the individual components taken separately, since the specific release characteristics (immediate-release esomeprazole layered over delayed-release naproxen) are designed to work together.

Naxin Plus 375mg + 20mg is supplied as an oral delayed-release tablet in which an immediate-release layer of esomeprazole magnesium (equivalent to 20 mg esomeprazole) surrounds a delayed-release core of naproxen (commonly available as 375 mg or 500 mg naproxen strengths).

The esomeprazole layer dissolves rapidly in the stomach to raise gastric pH, while the naproxen core is coated to resist dissolution until it reaches a higher-pH environment, delaying naproxen release until the stomach is less acidic.

Naxin Plus 375mg + 20mg combines naproxen, a propionic-acid-derivative nonsteroidal anti-inflammatory drug (NSAID), with esomeprazole magnesium, a proton pump inhibitor (PPI), in a single delayed-release tablet.

The rationale for this combination is that chronic NSAID use carries a well-documented risk of upper gastrointestinal ulceration and bleeding; co-administering a PPI reduces (but does not eliminate) this risk while the naproxen component continues to provide anti-inflammatory and analgesic activity for chronic joint conditions.

Naxin Plus 375mg + 20mg is intended for patients who need long-term NSAID therapy and who are also at risk for NSAID-associated gastric ulcers; it is not intended for patients who need only occasional or short-term pain relief.

Naxin Plus 375mg + 20mg belongs to the therapeutic class of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) combined with a Proton Pump Inhibitor (PPI), used as a fixed-dose combination for chronic musculoskeletal pain with gastroprotection.

Naxin Plus 375mg + 20mg has two active components with complementary mechanisms:

• Naproxen is a non-selective, reversible inhibitor of cyclooxygenase-1 and -2 (COX-1 and COX-2), the enzymes responsible for converting arachidonic acid to prostaglandins. By reducing prostaglandin synthesis, naproxen produces anti-inflammatory, analgesic, and antipyretic effects. Inhibition of protective gastric prostaglandins (via COX-1) is also the mechanism underlying NSAID-associated GI mucosal injury.
• Esomeprazole magnesium is the S-isomer of omeprazole and irreversibly inhibits the hydrogen-potassium adenosine triphosphatase (H+/K+-ATPase, the "proton pump") in gastric parietal cells, suppressing both basal and stimulated gastric acid secretion. Raising gastric pH reduces the incidence of NSAID-associated gastric ulcers.

In this formulation, esomeprazole is released immediately to raise gastric pH before the delayed-release naproxen core dissolves, which is why the tablet must be taken at least 30 minutes before a meal for esomeprazole to act optimally.

Naxin Plus 375mg + 20mg tablets should be swallowed whole with water at least 30–60 minutes before a meal. Do not crush, split, or chew the tablet. Missing the "before meal" timing reduces the protective benefit of the esomeprazole component. Take at approximately the same times each day, and do not double the dose if a dose is missed — take the next scheduled dose as usual.

Naxin Plus 375mg + 20mg contains an NSAID and a PPI, each with its own well-documented interactions:

Naproxen-related interactions

• Anticoagulants (e.g., warfarin) and antiplatelet agents: increased risk of serious GI bleeding; concomitant use requires close monitoring.
• Aspirin or other NSAIDs: increased risk of GI ulceration/bleeding without added therapeutic benefit; avoid combining.
• ACE inhibitors, angiotensin receptor blockers (ARBs), and diuretics: NSAIDs can reduce the antihypertensive effect and, combined with diuretics, increase the risk of acute kidney injury (the "triple whammy" effect).
• Lithium and methotrexate: naproxen can reduce renal clearance of these drugs, raising the risk of toxicity, particularly with high-dose methotrexate.
• Corticosteroids and SSRIs: additive increase in risk of GI ulceration or bleeding.

Esomeprazole-related interactions

• Clopidogrel: esomeprazole can reduce conversion of clopidogrel to its active metabolite, potentially reducing its antiplatelet effect; concomitant use should be avoided when possible.
• Rilpivirine-containing HIV medicines: esomeprazole substantially reduces rilpivirine absorption and concomitant use is contraindicated (see Contraindications).
• Drugs dependent on gastric pH for absorption (e.g., certain azole antifungals, atazanavir): esomeprazole-induced acid suppression can reduce their absorption and effectiveness.
• Methotrexate (high dose): PPIs may elevate and prolong methotrexate levels, increasing toxicity risk.

Side effects with Naxin Plus 375mg + 20mg may arise from either the NSAID or PPI component.

Common

• Dyspepsia, heartburn, abdominal pain, diarrhea, constipation, nausea
• Headache, dizziness
• Upper respiratory tract symptoms

Serious (less common but clinically important)

• Gastrointestinal ulceration, bleeding, or perforation (see Precautions and warnings)
• Cardiovascular thrombotic events such as myocardial infarction or stroke (see Precautions and warnings)
• Renal impairment, fluid retention, or elevated blood pressure
• Hepatic enzyme elevation or hepatotoxicity
• Hypersensitivity/anaphylactoid reactions and serious skin reactions (e.g., Stevens-Johnson syndrome)
• Long-term PPI-related effects: hypomagnesemia, vitamin B12 deficiency, increased fracture risk, and Clostridioides difficile-associated diarrhea

Pregnancy: Naxin Plus 375mg + 20mg is contraindicated in the third trimester of pregnancy due to the NSAID component's risk of causing premature closure of the fetal ductus arteriosus. Use of NSAIDs at or after 20 weeks of pregnancy has also been associated with fetal renal dysfunction leading to oligohydramnios. In the first and second trimesters, Naxin Plus 375mg + 20mg should be used only if clearly needed, after the potential benefit to the mother has been weighed against potential risk to the fetus, and only under a physician's supervision.

Lactation: Both naproxen and esomeprazole are excreted in breast milk in small amounts. Because of the potential for serious adverse effects in a nursing infant, a decision should be made to discontinue nursing or discontinue Naxin Plus 375mg + 20mg, taking into account the importance of the drug to the mother; consult a physician before use while breastfeeding.

Boxed warnings (class warnings for the NSAID component)

• Cardiovascular thrombotic risk: NSAIDs, including the naproxen component of Naxin Plus 375mg + 20mg, can increase the risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may increase with duration of use and may be higher in patients with existing cardiovascular disease or risk factors. Naxin Plus 375mg + 20mg is contraindicated for peri-operative pain in the setting of CABG surgery.
• Gastrointestinal risk: NSAIDs cause an increased risk of serious GI adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. While the esomeprazole component of Naxin Plus 375mg + 20mg reduces this risk compared with naproxen alone, it does not eliminate it, and elderly patients and those with a prior history of peptic ulcer disease or GI bleeding are at greater risk.

Other precautions

• Use the lowest effective dose for the shortest duration; periodically reassess the need for continued therapy.
• Avoid in severe renal or hepatic impairment; use caution and the lowest effective dose in mild-to-moderate impairment (see Use in special populations).
• NSAIDs can cause new-onset or worsening hypertension, fluid retention, and edema; use with caution in patients with heart failure.
• Long-term PPI use has been associated with hypomagnesemia, vitamin B12 deficiency, increased risk of bone fracture, and Clostridioides difficile-associated diarrhea; periodic monitoring may be appropriate for prolonged therapy.
• Naxin Plus 375mg + 20mg is not interchangeable with taking naproxen and esomeprazole separately, and dosing timing (at least 30–60 minutes before a meal) is important for the esomeprazole component to work as intended; do not crush, split, or chew the tablet.
• Serious skin reactions and anaphylactoid/hypersensitivity reactions can occur even without prior exposure; discontinue promptly if these occur.

Overdose of Naxin Plus 375mg + 20mg may present with symptoms related to the NSAID component (lethargy, drowsiness, nausea, vomiting, epigastric pain, gastrointestinal bleeding, transient elevation of blood pressure, acute kidney injury, and, rarely, seizures) and/or the PPI component (generally mild and self-limited symptoms; confusion, blurred vision, tachycardia, and sweating have been reported rarely with very high esomeprazole doses).

There is no specific antidote. In case of suspected overdose, seek immediate medical attention or contact a poison control center/emergency services right away; do not attempt specific home treatment.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Elderly

Elderly patients are at greater risk for NSAID-associated serious GI events and cardiovascular events; use the lowest effective dose of Naxin Plus 375mg + 20mg and monitor closely.

Renal impairment

Avoid use of Naxin Plus 375mg + 20mg in patients with severe renal impairment. In patients with mild-to-moderate renal impairment, use the lowest effective dose and monitor renal function, as NSAIDs can further reduce renal blood flow.

Hepatic impairment

Avoid use of Naxin Plus 375mg + 20mg in patients with severe hepatic impairment. In mild-to-moderate hepatic impairment, use the lowest effective dose with caution.

Pediatric use

Safety and efficacy of Naxin Plus 375mg + 20mg have not been established in pediatric patients; it is not recommended for use in patients under 18 years of age.

Naxin Plus 375mg + 20mg is intended for patients who require ongoing (chronic) NSAID therapy, such as for osteoarthritis, rheumatoid arthritis, or ankylosing spondylitis. It should be used at the lowest effective naproxen dose for the shortest duration consistent with the individual patient's treatment goals, with periodic reassessment by the prescribing physician, since both cardiovascular and gastrointestinal risks can increase with longer duration of use.

Nonsteroidal Anti-Inflammatory Drug (NSAID, propionic acid derivative) + Proton Pump Inhibitor (PPI) — fixed-dose combination

Naxin Plus 375mg + 20mg works through two complementary mechanisms. Naproxen non-selectively inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing synthesis of prostaglandins that mediate pain, inflammation, and fever. Esomeprazole magnesium irreversibly binds the H+/K+-ATPase proton pump in gastric parietal cells, suppressing gastric acid secretion; the resulting rise in gastric pH reduces the risk of NSAID-associated gastric mucosal injury. The tablet is engineered so esomeprazole is released immediately while naproxen release is delayed until gastric pH has risen, which is why correct dosing timing (before a meal) matters.

C (D in the third trimester, and contraindicated in the third trimester)

The safety and efficacy of Naxin Plus 375mg + 20mg have not been established in pediatric patients. It is not recommended for use in patients under 18 years of age, and no pediatric dosing has been established.