What are the options for pain control in patients with kidney stones?

Pain Control for Kidney Stones

First-Line Treatment: NSAIDs

NSAIDs are the first-line treatment for kidney stone pain, providing superior pain relief compared to opioids with fewer side effects and the added benefit of reducing ureteral spasm. 1

Why NSAIDs Work Best

• NSAIDs provide dual benefit: they not only control pain but also decrease ureteral smooth muscle tone and spasm that contribute to renal colic 1
• Multiple randomized controlled trials demonstrate that NSAIDs achieve greater reduction in pain scores, decreased need for rescue medications, and fewer vomiting events compared to opioids 2
• NSAIDs are significantly more effective than placebo in reducing pain by 50% within the first hour (RR 2.28,95% CI 1.47 to 3.51) 3
• Patients receiving NSAIDs are significantly less likely to require rescue medication than those receiving placebo (RR 0.35,95% CI 0.20 to 0.60) 3

Specific NSAID Recommendations

• Ketorolac 15-30 mg IV every 6-8 hours can be used for acute management, but limit use to maximum 5 days 4
• Indomethacin is less effective than other NSAIDs and should be avoided (RR 1.27,95% CI 1.01 to 1.60) 3
• Use any NSAID that the patient has previously tolerated well; otherwise consider ibuprofen up to 3200 mg daily maximum 5

Critical NSAID Precautions

• Avoid NSAIDs entirely in patients with chronic kidney disease (CKD) due to nephrotoxic effects 4
• Use with extreme caution in patients at high risk for renal, GI, cardiac toxicities, thrombocytopenia, or bleeding disorders 5, 4
• High-risk patients include: age ≥60 years, compromised fluid status, history of peptic ulcer disease, cardiovascular disease, or concomitant nephrotoxic drugs 5
• Monitor baseline and every 3 months: blood pressure, BUN, creatinine, liver function studies, CBC, and fecal occult blood 5, 4
• Discontinue NSAIDs immediately if BUN or creatinine doubles, hypertension develops or worsens, or liver function studies increase beyond normal limits 4

When to Avoid Antispasmodics

• Do not use antispasmodics as monotherapy—NSAIDs are significantly more effective (MD -12.97,95% CI -21.80 to -4.14) 3
• Adding antispasmodics to NSAIDs provides no additional benefit (RR 1.00,95% CI 0.89 to 1.13) 3

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Alternative First-Line: Acetaminophen

For patients with contraindications to NSAIDs (particularly those with CKD or ESKD), acetaminophen is the safest first-line alternative. 1, 4

• Maximum dose: 3000 mg/day (typically 650 mg every 6 hours) 4
• Acetaminophen is the preferred first-line agent for patients with chronic kidney disease or end-stage kidney disease 4
• No renal toxicity concerns and does not affect platelet function 6

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Second-Line Treatment: Opioids for Severe Pain

Reserve opioids only for moderate to severe pain unresponsive to NSAIDs or acetaminophen, and use the lowest effective dose for the shortest duration. 1

Pre-Opioid Requirements

• Before prescribing opioids, assess risk of substance abuse and obtain informed consent after discussing goals, expectations, potential risks, and alternatives 1, 4
• Implement risk mitigation strategies and monitor for signs of dependence 1

Safest Opioid Choices

• Fentanyl and buprenorphine are the safest opioids for patients with kidney disease due to favorable pharmacokinetic profiles 4, 6
• Other acceptable options in kidney disease: oxycodone, hydromorphone, methadone 6
• Buprenorphine is particularly promising due to its partial agonism at the mu opioid receptor, resulting in fewer adverse events 6

Opioid Management Essentials

• Proactively prescribe laxatives for prophylaxis of opioid-induced constipation 4
• Monitor for signs of opioid toxicity, which may occur at lower doses in CKD patients 7
• Provide rescue doses for breakthrough pain episodes 4
• Recent data shows opioid use in emergency departments for kidney stones decreased significantly from 2015 to 2021 (annual OR 0.87), reflecting improved stewardship 8

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Adjunctive Therapies

For Neuropathic Pain Components

• Gabapentin or pregabalin can be used but require significant dose adjustment in kidney disease 4
• Start gabapentin at 100-300 mg at night with careful titration in patients with kidney disease 4

Topical Options

• Lidocaine 5% patch and diclofenac gel can be used for localized pain without significant systemic absorption 4

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Non-Pharmacological Interventions

• Increased fluid intake to achieve urine volume of at least 2.5 liters daily facilitates stone passage 1
• Application of local heat can provide relief without affecting renal function 7, 4
• Physical activity/exercise programs should be considered as initial treatment 4

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Monitoring and Follow-Up

• Regular pain assessment using validated tools (such as VAS) is essential for quality care 1, 4
• For chronic pain, prescribe analgesics on a regular schedule rather than "as required" 4
• Always include rescue doses of medications for breakthrough pain 4
• Monitor for potential adverse effects including renal function, blood pressure, and gastrointestinal symptoms 1

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Common Pitfalls to Avoid

• Do not combine NSAIDs with antispasmodics expecting better results—no additional benefit is demonstrated 3
• Avoid indomethacin specifically as it is less effective than other NSAIDs 3
• Do not use NSAIDs for extended periods in patients with kidney disease without close monitoring 6
• Recognize that 35% of patients historically received opioids stronger than morphine—this is excessive for most kidney stone pain 8
• Be aware of disparities: Black patients and female patients are less likely to receive adequate discharge prescriptions 8