Intravenous Ketamine for Chronic Pain: Efficacy, Safety, and Clinical Insights

Introduction Chronic pain disrupts daily functioning and poses significant challenges to quality of life. Intravenous ketamine has emerged as a promising option for managing chronic pain, offering a novel approach through its unique pharmacological profile. Initial evidence suggests ketamine’s effectiveness is primarily due to its NMDA receptor antagonism, modulating pain pathways and reducing central sensitization [1]. Additionally, studies indicate ketamine provides hemodynamic stability and minimal side effects during administration, making it a promising option for chronic pain management [2]. Despite growing acceptance, further investigation is needed to understand its full clinical potential and broader implications for symptom relief and safety. Aim To evaluate the therapeutic efficacy and safety of intravenous ketamine in managing pain, with a focus on symptom improvement, hemodynamic changes, and side effects. Methods This retrospective study analyzed 75 patients (53% male; mean age 68.7 years) with chronic pain and diverse comorbidities who received i.v. ketamine (0.15 mg/kg). Data on pain intensity, associated symptoms, hemodynamic parameters, and work-related pain onset factors were obtained from an anonymous questionnaire previously administered to patients during one of their 1st to 6th treatment sessions. Results Pain scores significantly reduced, decreasing from 9.07 to 5.4, representing a 40.4% improvement (p < 0.01). Stabbing pain emerged as the most commonly reported type (75%, n = 56), with 30% (n = 22) of patients indicating radiation into the legs and buttocks. Ketamine demonstrated the highest efficacy for lower back pain, achieving an average reduction of 41.5% (p < 0.01), while also showing favorable outcomes for other pain regions (34.9%, p < 0.01). At baseline, patients reported frequent sleep disturbances (85%, n = 64), reduced physical activity (72%, n = 54), and emotional distress (68%, n = 51). Post-treatment evaluations revealed significant improvements, particularly in sleep quality (64%, n = 48, p < 0.01), emotional well-being (36%, n = 27, p < 0.01), and physical activity (22.7%, n = 17, p < 0.01). Hemodynamic parameters remained stable, with minor, non-significant reductions observed in systolic blood pressure (6.2 mmHg, p = 0.067), diastolic blood pressure (4.7 mmHg, p = 0.082), and heart rate (3.1 bpm, p = 0.091). The reported side effects were minimal, with only 4% (n = 3) of patients experiencing mild dizziness and no additional adverse events noted. Conclusions Intravenous ketamine (0.15 mg/kg) significantly reduces pain intensity and improves chronic pain symptoms, with minimal side effects. Its particular effectiveness for lower back pain highlights its role as a safe and valuable option for chronic pain management. Further studies with larger, controlled cohorts are warranted to expand on these findings and confirm its therapeutic potential.