Effects of Intravenous Lidocaine as an Analgesic Adjuvant in Oncological Pain

Objectives: To verify that intravenous lidocaine is effective as an adjuvant analgesic in pain for hospitalized cancer patients at the National Institute of Cancerology, Mexico. Methods: Clinical records of patients hospitalized at the National Institute of Cancerology who received intravenous lidocaine infusion as an adjuvant to pain during the 4-year period from November 1, 2019, to October 31, 2023, were reviewed. Patients who met inclusion and exclusion criteria were included. A statistically significant measure was defined as a decrease equal to or greater than 4 points in the NRS value after lidocaine administration. Results: A total of 179 patients were included; 46.4% were men, and 53.6% were women. The most common painful syndrome was somatic (54%). Patients with neuropathic pain received a higher lidocaine dose (mg/kg/hr) of 1.9 ± 0.79. Regarding adverse effects, 1.7% of patients experienced them. It was established that a reduction of 4 points with respect to the previous value on the numeric rating scale (NRS) would be considered statistically significant. A statistically significant association was found between patients under 38 years old and a higher risk of not achieving the objective (p 0.05, CI 0.95–1 OR 0.9). Patients who received lidocaine infusions for less than 4.63 days also had a risk of not reaching the goal (p 0.02, CI 0.7–0.9, OR 0.8). Conclusions: This study demonstrated that the analgesic adjuvant use of intravenous lidocaine infusion is an effective and well-tolerated analgesic intervention for oncology patients. Keywords: lidocaine, Neuropathic Pain, Somatic Pain, Visceral Pain, numeric rating scale.