What is the recommended treatment for a patient with renal colic?

Treatment of Renal Colic

Intramuscular diclofenac 75 mg is the recommended first-line treatment for patients with renal colic when the diagnosis is clear and there are no signs of complications. 1

Diagnosis and Initial Assessment

When evaluating a patient with suspected renal colic:

• Look for the classic presentation: abrupt onset of severe unilateral flank pain radiating into the groin or genitals 1
• Perform urinalysis if possible - haematuria is present in over 80% of cases and supports the diagnosis 1
• Examine the abdomen to establish site of maximal tenderness and exclude other conditions such as peritonitis 1
• Check vital signs to rule out shock and systemic infection 1
• Consider alternative diagnoses, particularly:
  • Leaking abdominal aortic aneurysm (especially in patients >60 years)
  • Ruptured ectopic pregnancy in women of childbearing age

Treatment Algorithm

1. First-line analgesic therapy:

   • Administer intramuscular diclofenac 75 mg when diagnosis is clear 1
   • Intramuscular route is preferred as oral and rectal administration are considered unreliable, and IV administration is often impractical in primary care settings 1

2. If NSAIDs are contraindicated:

   • Use an opiate combined with an antiemetic (e.g., morphine sulfate with cyclizine) 1, 2
   • Morphine is particularly preferred during pregnancy when NSAIDs are contraindicated 2

3. Follow-up after initial treatment:

   • Contact patient by telephone one hour after administration of analgesia 1
   • If pain is not relieved within 60 minutes, arrange immediate hospital admission 1
   • For abrupt recurrence of severe pain, arrange immediate hospital admission 1

4. For patients managed at home:

   • Encourage high fluid intake
   • Have patient void urine through a strainer or gauze to catch any passed stones 1
   • Arrange fast-track urological investigation with follow-up 1

Evidence for Analgesic Efficacy

• NSAIDs are significantly more effective than placebo and antispasmodics for renal colic pain 3
• NSAIDs and strong opioid analgesics have comparable efficacy for pain relief 2
• NSAIDs are associated with fewer adverse effects than opioids (vomiting occurs in ~6% with NSAIDs vs ~20% with opioids) 2
• Indomethacin appears less effective than other NSAIDs for pain control 3
• The combination of NSAIDs with antispasmodics does not provide superior pain relief compared to NSAIDs alone 3

Important Considerations and Cautions

• Immediate hospital admission is required for patients with:

  • Shock or fever 1
  • Pain not relieved within one hour of analgesia 1
  • Abrupt recurrence of severe pain 1

• NSAID cautions:

  • Avoid in patients with risk of functional renal impairment (heart failure, renal artery stenosis, dehydration, existing renal impairment) 2
  • Absolutely contraindicated during pregnancy 2
  • Use with caution in elderly patients 2

• For pregnant patients:

  • Morphine carries a lower risk of adverse effects than NSAIDs 2

Follow-up Care

All patients with renal colic, whether managed at home or in hospital, should be offered fast-track urological investigation with appropriate follow-up to:

• Confirm the diagnosis
• Determine stone size and location
• Plan appropriate management of the underlying condition 1

The risk of urolithiasis recurrence is high (up to 40% in 5 years and 50% in 10 years), so preventive measures should be discussed during follow-up 4.