What is the recommended dose of Naprosyn (naproxen) for managing kidney stones?

Naproxen Dosing for Kidney Stone Management

For acute kidney stone pain management, the recommended starting dose of naproxen is 500 mg, followed by 500 mg every 12 hours or 250 mg every 6-8 hours as required, with initial total daily dose not exceeding 1250 mg and subsequent daily doses not exceeding 1000 mg. 1

Initial Pain Management Approach

• NSAIDs, including naproxen, are recommended as first-line treatment for acute kidney stone pain due to superior efficacy, fewer side effects, and lower risk of dependence compared to opioids 2
• Naproxen should be used at the lowest effective dose due to potential cardiovascular and gastrointestinal risks, particularly in patients with reduced kidney function 2
• Pain relief with naproxen can begin within 1 hour after administration 1
• Opioids should be reserved as second-choice analgesics when NSAIDs are contraindicated or ineffective 2

Dosing Considerations

• For kidney stone pain management, use naproxen sodium for more rapid absorption when prompt pain relief is desired 1
• The recommended dosing schedule:
  • Initial dose: 500 mg 1
  • Maintenance: 500 mg every 12 hours or 250 mg every 6-8 hours as needed 1
  • Maximum initial daily dose: 1250 mg 1
  • Maximum subsequent daily dose: 1000 mg 1

Renal Function Considerations

• Naproxen is not recommended for patients with moderate to severe renal impairment (creatinine clearance <30 mL/min) 1
• For elderly patients or those with mild renal impairment, consider starting at a lower dose and adjusting based on clinical response 1
• Naproxen is primarily eliminated following biotransformation to glucuroconjugated and sulphate metabolites which are excreted in urine 3

Pharmacokinetic Considerations

• Naproxen is rapidly and completely absorbed after oral administration 4
• It has a relatively long half-life (approximately 13 hours), which permits twice-daily dosing 5
• The drug is highly protein-bound, with binding occurring in a concentration-dependent manner 3
• At doses greater than 500 mg, there is an increase in the unbound fraction of drug, leading to increased renal clearance 3

Hydration and Additional Management

• Adequate hydration is essential for kidney stone management - recommend fluid intake that will achieve urine volume of at least 2.5 liters daily 6
• A daily intake of at least 1.5 liters of water usually helps prevent stone formation, especially in those with risk factors 6
• Dietary modifications should be considered based on stone composition (limiting sodium intake and maintaining normal calcium consumption for calcium stones) 6

Cautions and Monitoring

• Monitor renal function during treatment, especially in patients with pre-existing kidney disease 7
• Even short-term use of naproxen can potentially cause nephrotoxicity in susceptible individuals 7
• Avoid using naproxen in patients with known kidney disease or those at high risk for acute kidney injury 2
• Be cautious when using naproxen in patients taking other medications that may interact, such as warfarin, sulfonylureas, and aspirin 5