What prescription medications are recommended for pain control in renal colic?

Prescription Medications for Pain Control in Renal Colic

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

First-Line Treatment: NSAIDs

• NSAIDs are the first-line treatment for renal colic due to their superior efficacy and safety profile compared to opioids 1
• Diclofenac 75 mg administered intramuscularly is specifically recommended as the initial treatment of choice 1
• NSAIDs reduce the need for additional analgesia compared to opioids and have fewer side effects 1, 2
• The intramuscular route is preferred for initial treatment as oral and rectal administration are considered less reliable in acute severe pain 3
• For IV NSAID administration, ketorolac has been shown to be effective at doses of 10-30 mg, with no significant difference in efficacy between these doses 4, 5

Second-Line Treatment: Opioids

• When NSAIDs are contraindicated or insufficient for pain control, opioids should be used as second-line therapy 1, 2
• Opioids (particularly pethidine/meperidine) are associated with a higher rate of vomiting (approximately 20%) compared to NSAIDs (approximately 6%) 2
• If an opioid is required, agents other than pethidine are recommended, such as hydromorphone, pentazocine, or tramadol 1
• For patients with renal impairment, fentanyl is preferred as it does not accumulate active metabolites in renal failure 6
• Morphine should be used with caution in patients with renal impairment due to the risk of accumulation of toxic metabolites 6, 7

Special Considerations

• If severe pain does not remit within one hour of initial treatment, the patient should be admitted to hospital 1
• In cases of sepsis and/or anuria in an obstructed kidney, urgent decompression of the system via percutaneous nephrostomy or ureteral stenting is strongly recommended before definitive treatment 1
• For pregnant women, morphine carries a lower risk of adverse effects than NSAIDs, which should be avoided 2
• NSAIDs should be avoided in patients with heart failure, renal artery stenosis, dehydration, renal impairment, or those on nephrotoxic drugs 2
• Medical expulsive therapy (alpha-blockers) may be beneficial for patients with stones >5 mm in the distal ureter 1

Combination Therapy

• According to one trial, the combination of morphine and an NSAID provided greater analgesic effect than either agent alone in approximately 10% of patients 2
• When using combination therapy, monitor patients closely for respiratory depression, especially when combining opioids with benzodiazepines 6, 7

Monitoring and Follow-up

• Complete or acceptable pain control should be maintained for at least six hours 3
• Patients should be followed up (via telephone call) one hour after initial assessment and administration of analgesia 3
• Abrupt recurrence of severe pain warrants immediate hospital admission 3
• Patients should be instructed to drink plenty of fluids and, if possible, void urine into a container to catch any identifiable calculus 3

Common Pitfalls to Avoid

• Do not delay analgesia while waiting for diagnostic tests 3
• Avoid using standard opioid dosing protocols for patients with renal failure; always start with lower doses and titrate carefully 6
• Never use morphine, codeine, or tramadol as first-line agents in patients with renal failure 6
• Avoid meperidine in patients with renal impairment due to the risk of neurotoxicity from accumulation of normeperidine 6
• Do not issue limited quantities of oral or rectal analgesics for patients with recurrent pain due to potential for drug misuse 3