What medications are used to manage kidney stone pain?

Pain Management for Kidney Stones

NSAIDs, specifically diclofenac, ibuprofen, or ketorolac, should be the first-line medication for kidney stone pain, as they provide superior pain control compared to opioids, reduce the need for rescue analgesia, and cause less vomiting. 1, 2, 3

First-Line Treatment: NSAIDs

NSAIDs are the preferred initial analgesic for renal colic based on multiple high-quality studies demonstrating their superiority over opioids 1, 2, 3. The mechanism involves both pain relief and reduction of ureteral smooth muscle tone and spasm 1.

Specific NSAID options include:

• Ketorolac 15-30 mg IV for acute severe pain, maximum 5 days duration 1, 2
• Ibuprofen 400 mg orally up to 3200 mg daily maximum 1
• Diclofenac (oral or intramuscular formulations) 2
• Naproxen as an alternative oral NSAID 4

NSAIDs demonstrate marginal but statistically significant benefit over opioids in initial pain reduction at 30 minutes (mean difference -5.58 on pain scale) 3. More importantly, NSAIDs require fewer rescue treatments (NNT 11) and have lower vomiting rates (NNT 5) compared with opioids 3.

Critical Safety Considerations Before Prescribing NSAIDs

You must assess these contraindications before prescribing NSAIDs:

• Renal impairment: NSAIDs can worsen kidney function and should be avoided or used with extreme caution in patients with compromised renal function 1, 2
• Cardiovascular disease or risk factors: NSAIDs increase risk of major coronary events, particularly in patients with hypertension, heart failure, or cardiovascular disease 1
• Gastrointestinal risk: Age >60 years, history of peptic ulcer disease, significant alcohol use (≥2 drinks daily), or concurrent anticoagulant use 1, 4
• Bleeding disorders or thrombocytopenia: NSAIDs inhibit platelet aggregation 1

Monitoring Requirements for NSAID Use

Before initiating NSAIDs, obtain:

• Baseline blood pressure, BUN, creatinine 1, 2
• Liver function studies (alkaline phosphatase, LDH, SGOT, SGPT) 1
• CBC and fecal occult blood 1

Repeat monitoring every 3 months during continued use 1, 2

Discontinue NSAIDs immediately if:

• BUN or creatinine doubles 1, 2
• Hypertension develops or worsens 1, 2
• Liver function studies increase above normal limits 1, 2
• Peptic ulcer or gastrointestinal hemorrhage occurs 1, 2

Second-Line Treatment: Opioids

Opioids should only be used when NSAIDs are contraindicated or ineffective 1, 2. The 2022 CDC guidelines emphasize that NSAIDs are at least as effective as opioids for kidney stone pain 1.

Preferred opioid options when necessary:

• Hydromorphine 2
• Tramadol 2
• Pentazocine 2

Avoid pethidine (meperidine) due to high rate of adverse effects among opioids for renal colic 2.

For patients with chronic kidney disease stages 4-5 who cannot tolerate NSAIDs, fentanyl and buprenorphine (transdermal or IV) are the safest opioid choices as they do not accumulate active metabolites 2, 5.

Alternative Analgesics

Acetaminophen (paracetamol) can be considered but is less effective than NSAIDs 1, 3. Studies show NSAIDs and paracetamol have equivalent pain relief at 30 minutes, but patients treated with NSAIDs required significantly fewer rescue treatments (risk ratio 0.56) 3. Maximum dose is 3000-4000 mg daily 1, 5.

Common Pitfalls to Avoid

• Do not default to opioids out of fear of NSAID side effects in patients with adequate renal function—the evidence clearly favors NSAIDs for both efficacy and safety profile 1, 2, 3
• Do not use NSAIDs long-term without monitoring in patients with borderline renal function 2
• Do not overlook urgent decompression needs if sepsis or anuria is present—pain control is secondary to emergent intervention in these cases 2
• Do not prescribe NSAIDs with concurrent anticoagulants (warfarin, heparin) without careful consideration, as this significantly increases bleeding risk 1, 4
• Do not use NSAIDs in late pregnancy as they may cause premature closure of the ductus arteriosus 4

Practical Implementation Algorithm

1. Assess renal function, cardiovascular status, GI risk, and bleeding risk
2. If no contraindications exist: Start ketorolac 15-30 mg IV for immediate relief OR ibuprofen 400 mg orally 1, 2
3. If NSAIDs contraindicated: Use opioids (hydromorphine, tramadol, or pentazocine preferred) 2
4. If partial response to NSAIDs: Continue NSAID and add acetaminophen 650 mg every 6 hours 1, 5
5. Monitor for NSAID toxicity with repeat labs every 3 months if continued use 1, 2