Lidocaine infusions were shown to provide long-lasting and adequate analgesia in 41% of patients with chronic pain, and to be associated with mild side effects in a study recently published in Pain Medicine.1
Researchers retrospectively reviewed the charts of 233 adult patients (average age, 51; 54% women) with chronic pain (average pain duration, 7.7 years; 80% with neuropathic pain) who had received an initial lidocaine challenge of 1000 mg/h for ≤30 minutes (infusion rate, 16.67 mg/min), followed by up to 2 more lidocaine infusions (average lidocaine administered during first infusion, 381.4 mg). Lidocaine infusions were discontinued upon complete pain relief, experiencing of intolerable side effects, after 30 minutes of infusion, or if requested by patients.
The initial lidocaine infusion led to side effects in 47% of patients (most commonly, perioral tingling, 9.87%; dizziness, 7.73%; and tinnitus, 5.58%). Fewer side effects were reported for the second and third lidocaine infusions.
A total of 41% of patients in the study experienced pain relief after the initial infusion, with an average pain relief of 1 to 2 weeks across the study cohort. Among patients who experienced benefits from the challenge infusion (100% of patients with diabetic neuropathic pain; 57.1% with posttraumatic or postsurgical pain; 55.6% with trigeminal neuralgia; 50.0% with migraine or headache), 94% were administered another infusion, 60% of whom continued to benefit from the treatment. Clinical diagnosis, demographics, and pain duration had no significant effect on the likelihood of achieving pain relief from the lidocaine treatment.
Patients who experienced side effects were less likely to benefit from lidocaine treatment. In addition, patients who did not receive benefit from the initial lidocaine challenge (40.3%) were less likely to receive additional infusions.