Is hyoscine (scopolamine) effective for treating renal colic?

Hyoscine for Renal Colic: Not Recommended as First-Line Treatment

NSAIDs, not hyoscine (scopolamine), should be used as first-line treatment for renal colic due to superior efficacy and safety profile. 1

First-Line Treatment for Renal Colic

NSAIDs are strongly recommended as the first-line treatment for renal colic pain for several important reasons:

• They directly address the pathophysiological mechanism of renal colic by reducing prostaglandin production, which causes vasoconstriction and increased pressure in the ureter 2
• The European Association of Urology (EAU) guidelines specifically recommend NSAIDs (diclofenac, ibuprofen, metamizole) as first-line treatment 1
• NSAIDs reduce the need for additional analgesia compared to opioids 1, 3
• Patients treated with NSAIDs have lower pain scores and reduced need for rescue medication compared to other analgesics 2, 3

The preferred NSAID administration for acute renal colic is:

• Intramuscular diclofenac 75 mg as the preferred first-line treatment 1, 2
• The lowest effective dose should be used to minimize cardiovascular and gastrointestinal risks 1

Evidence Against Hyoscine for Renal Colic

Hyoscine (scopolamine) is not recommended as a primary treatment for renal colic for the following reasons:

1. NSAIDs are significantly more effective than hyoscine in pain reduction (RR 2.44,95% CI 1.61 to 3.70) 3
2. Patients receiving NSAIDs are significantly less likely to require rescue medicine than those receiving antispasmodics like hyoscine (RR 0.34,95% CI 0.14 to 0.84) 3
3. Adding antispasmodics like hyoscine to NSAIDs does not result in better pain control (RR 1.00,95% CI 0.89 to 1.13) 3

One study did show some benefit of hyoscine N-butyl bromide in combination with desmopressin compared to hyoscine alone 4, but this does not override the stronger evidence supporting NSAIDs as first-line therapy.

Alternative Analgesics When NSAIDs Are Contraindicated

If NSAIDs are contraindicated (e.g., in patients with severe renal impairment, heart failure, or during pregnancy), the following alternatives should be considered:

• Opioids are recommended as second-choice analgesics 1
• If an opioid is required, agents other than pethidine are recommended, such as hydromorphine, pentazocine, or tramadol 1
• Opioids combined with an antiemetic, such as morphine sulfate and cyclizine, should be given 1

Important Cautions with Opioids

• Opioids, particularly pethidine, are associated with a higher rate of vomiting compared to NSAIDs 1, 5
• Opioids are more likely to require further analgesia compared to NSAIDs 1, 5

Clinical Assessment and Management Algorithm

1. Diagnosis: Based on abrupt onset of severe unilateral flank pain radiating into the groin or genitals 1, 2

   • Perform urinalysis - haematuria supports the diagnosis (present in >80% of cases) 1, 2
   • Examine the abdomen to establish site of maximal tenderness 1, 2
   • Check vital signs to exclude shock and systemic infection 1, 2

2. Immediate Red Flags requiring hospital referral 2:

   • Shock
   • Fever
   • Oligoanuria
   • Age over 60 years (consider abdominal aortic aneurysm)
   • Delayed menses in women (consider ectopic pregnancy)

3. Treatment Protocol:

   • First-line: Intramuscular diclofenac 75 mg 1, 2
   • Reassess pain after 60 minutes 1
   • If pain is not alleviated within 60 minutes, arrange immediate hospital admission 1
   • If NSAIDs are contraindicated, use opioids with an antiemetic 1

4. Post-Treatment Instructions:

   • High fluid intake 1
   • Void urine into a container or through a strainer to catch any passed calculus 1
   • Contact doctor if pain worsens or new symptoms develop 1

Conclusion

Based on the most recent and highest quality evidence, hyoscine (scopolamine) is not recommended for treating renal colic. NSAIDs remain the first-line treatment with superior efficacy and safety profile compared to antispasmodics like hyoscine or opioids. When NSAIDs are contraindicated, opioids other than pethidine should be used as second-line therapy.