Parenteral lidocaine for treatment of intractable renal colic: a case series

Because of inconsistent responses to standard treatment with opioids and non-steroidal anti-inflammatory drugs in patients with renal colic pain, we decided to begin a trial of a single intravenous dose of lidocaine (approximately 1.5 mg/kg) slowly in eight patients with intractable renal colic who were referred to our emergency medicine department. The patients were six men and two women with a mean age at diagnosis of 34.62 years (age range, 28 to 42 years). The patients were of Iranian ethnic origin. The patients' degree of pain, based on Visual Analog Scale score upon entering our emergency medicine department, was recorded 10, 20, and 30 minutes after lidocaine injection. The patients' degree of pain decreased from a mean Visual Analog Scale score (±SD) of 8.87 ± 0.99 (95% confidence interval (95% CI) 8.04 to 9.70) to a mean Visual Analog Scale score (±SD) of 1 ± 2.82 (95% CI -1.36 to 3.36) before and 30 minutes after lidocaine treatment, respectively. Two of eight patients experienced transient mild dizziness, and three of eight patients experienced minimal slurring of speech. No patient experienced serious adverse events.Parenteral lidocaine treatment can reduce pain dramatically or subtly.Numerous medications have been utilized for pain relief in patients with renal colic; however, no medication has yet been found to relieve pain quickly and completely. A variety of drugs are used to treat this condition, including anti-spasmodics, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids [1]. Parenteral lidocaine has been reported to be effective in small studies of various neuropathic pain conditions, including diabetic neuropathy, post-operative pain, post-herpetic neuralgia, centrally mediated pain, headache, and malignant nerve infiltration [2-5].Eight patients (mean age (±SD) 34.62 ± 4.34 years, six men and two women) with intractable renal colic who presented to our emergency department were enrolled into this study. All included patients previously