Ketamine For Chronic Pain Research Articles

Ketamine in Chronic Pain: A Review.

Ketamine has been used in the treatment of several pain syndromes, particularly those with a relevant neuropathic component. Sub-anesthetic doses of ketamine produce a potent analgesic effect, due to its inhibition of N-methyl-D-aspartate receptors and enhancement of descending inhibitory pathways. Its short-term analgesic effect is well-documented perioperatively, with an associated reduction in postoperative chronic pain and opioid consumption. Despite some evidence regarding its long-term benefits, the number of clinical studies is still limited. In addition to its analgesic effects, ketamine also possesses an anti-depressive action, which might be useful in the treatment of chronic pain patients. Several side effects have been described, the psychomimetic ones being the most relevant due to their impact on treatment adhesion. At present, co-administration of ketamine and benzodiazepines or α2-agonists facilitates its clinical application. Despite current evidence and increasing use, further investigation is still needed regarding its long-term safety profile and clearer risk-benefit analysis.

Ketamine for Chronic Pain and Mental Health: Regulations, Legalities, and the Growth of Infusion Clinics.

In this article, we will review evidence for ketamine's role in chronic pain and mental health conditions, its current legal status and abuse potential, and the regulations related to its administration in stand-alone infusion clinics, as well as future considerations. In the management of chronic pain, ketamine has shown potential to manage neuropathic pain and complex regional pain syndrome and has been used as a treatment for chronic pain management by clinics across the USA. Analogous to the historic rise of lidocaine clinics, ketamine clinics are demonstrating a similar pattern of unregulated growth. Ketamine is an anesthetic and analgesic agent commonly used in the perioperative setting and emergency department for sedation and pain management (Mo et al in West J Emerg Med 21(2):272-281, 2020). It was approved for use by the Federal Drug Administration in the USA in the 1970s as the sole anesthetic agent for short diagnostic and surgical procedures (Coppel et al. in Anaesthesia 28(3):293-296,1973; Schwenk et al. in Reg Anesth Pain Med 43(5):456-466, 2018). Regarding its rising popularity as a treatment option in mental health, ketamine holds promise as a rapidly acting treatment for suicidal ideation and refractory depression.

Ketamine in chronic pain

Ketamine is now frequently used in the management of chronic pain refractory to conventional treatments. However, its efficacy and adverse effects appear variable in the literature in line with heterogeneous methodologies and modes of administration, leading to controversy regarding the actual interest of ketamine for chronic pain treatment. A need for clinical trials on larger cohorts of well selected patients but also real-life studies to more accurately quantify its efficacy, refine its prescription dosages and better understand its long-term adverse effects is highlighted in the literature. Progress in this direction has been achieved in recent years with improved recommendations for use, taking into account different trajectories of analgesia with ketamine, depending on the etiology of the pain, and the psycho-affective profile of patients. A holistic approach is clearly needed with consideration of pain and depression comorbidities to optimize pain management.

Ketamine in chronic pain: A Delphi survey.

There is no recommendation in Europe for the use of ketamine in patients with chronic pain. The heterogeneity of practice highlights the need to seek the advice of experts in order to establish a national consensus. This Delphi survey aimed to reach a national consensus on the use of ketamine in chronic pain in Pain clinics. A collaborative four-round internet-based questionnaire was used. It was created after literature search on ketamine administration in chronic pain and included about 96 items. It discussed utility and advantages, adverse events and deleterious aspects, methods of administration, concomitant treatments and assessment of results. Twenty-eight experts completed all rounds of the survey with a total of 81.3% items reaching a consensual answer. Neuropathic pain represents the first indication to use ketamine, followed, with a good to moderate utility, by other situations (fibromyalgia, complex regional pain syndrome, central neuropathic pain, peripheral neuropathic pain, nociceptive pain, sensitization, opioid withdrawal, palliative care, depression). Experts agreed on the rare occurrence of adverse events. Concerning routes of administration, intravenous infusion with doses of 0.5-0.9mg/kg/d for 4days of treatment is preferred. Place of care is hospital, as in- or out-patient, with a quarterly administration of ketamine. Finally, ketamine effectiveness is assessed 1month after infusion, and experts encourage combination with non-pharmacological treatment. This Delphi survey established a consensus of pain specialists on the use of ketamine in refractory chronic pain, thus providing a basis for future comparative trials. This Delphi survey in chronic pain reached agreement on four main aspects: (1) Priority to treat neuropathic pain with evaluation of effectiveness at 1month; (2) No deleterious effects in the majority of listed diseases/situations with the absence or <3% of suggested adverse events; (3) 0.5-0.9mg/kg/d IV infusion; (4) Combination with non-pharmacological treatment.

Kétamine et douleur chronique : une revue narrative de son efficacité et sécurité

Ketamine is frequently used in the management of refractory chronic pain. To date, the level of proof in the literature on ketamine in this type of indication is generally poor and physicians have no consensus or recommendation to support their practice. This narrative review is an update on literature data assessing the efficacy and safety of ketamine in chronic pain. The electronic search of the Medline, PubMed, Google Scholar and Cochrane databases identified a total of 61 articles including randomized and non-randomized trials and 14 international reviews. In view of these data, it is difficult to conclude on the effectiveness of ketamine in this type of indication and on its safety due to the heterogeneity of practice in terms of doses, routes, duration and frequency of administration and especially a lack of clinical trials with a high level of evidence.

Ketamine in chronic pain : a randomised clinical trial

Ketamine in chronic pain : a randomised clinical trial

Ketamine for chronic pain: risks and benefits

The anaesthetic ketamine is used to treat various chronic pain syndromes, especially those that have a neuropathic component. Low dose ketamine produces strong analgesia in neuropathic pain states, presumably by inhibition of the N-methyl-D-aspartate receptor although other mechanisms are possibly involved, including enhancement of descending inhibition and anti-inflammatory effects at central sites. Current data on short term infusions indicate that ketamine produces potent analgesia during administration only, while three studies on the effect of prolonged infusion (4-14 days) show long-term analgesic effects up to 3 months following infusion. The side effects of ketamine noted in clinical studies include psychedelic symptoms (hallucinations, memory defects, panic attacks), nausea/vomiting, somnolence, cardiovascular stimulation and, in a minority of patients, hepatoxicity. The recreational use of ketamine is increasing and comes with a variety of additional risks ranging from bladder and renal complications to persistent psychotypical behaviour and memory defects. Blind extrapolation of these risks to clinical patients is difficult because of the variable, high and recurrent exposure to the drug in ketamine abusers and the high frequency of abuse of other illicit substances in this population. In clinical settings, ketamine is well tolerated, especially when benzodiazepines are used to tame the psychotropic side effects. Irrespective, close monitoring of patients receiving ketamine is mandatory, particularly aimed at CNS, haemodynamic, renal and hepatic symptoms as well as abuse. Further research is required to assess whether the benefits outweigh the risks and costs. Until definite proof is obtained ketamine administration should be restricted to patients with therapy-resistant severe neuropathic pain.

Ketamine for chronic noncancer pain

Ketamine misuse and abuse is on the increase. This review focuses on recent studies on ketamine toxicity in recreational users and possible implications for the use of ketamine in chronic pain therapy. Urological toxicity, hepatotoxicity and cognitive deficits are all reported as adverse effects of the recreational use of ketamine. Urological toxicity and hepatotoxicity have been reported as adverse effects of ketamine in pain therapy. These findings may have implications for the clinical use of ketamine in chronic noncancer pain conditions. Until safety issues are resolved, it is suggested that chronic pain treatment involving higher doses and repeated exposure to ketamine be restricted to the context of randomized, controlled trials or clinical audits.

Ketamine for Chronic Pain and Treatment Resistant Depression: A Mechanistic Hypothesis

Chronic Pain syndromes and Major Depressive Disorder account for two of the most costly and prevalent illnesses worldwide and are frequently comorbid and treatment resistant. In this review, we examine the current role of ketamine, a potent NMDA (N-methl-D-aspartic acid) receptor blocker, in treating chronic pain and major depression. The role of the NMDA receptor and glutamatergic system are increasingly being studied in mood disorders, and are known components in pain processing, opioid induced analgesic tolerance, and hyperalgesia. We propose a hypothetic therapeutic role of ketamine involving the opioidergic pathway in these patients with treatment resistant chronic pain and major depressive disorder.

Histological Findings After Long-Term Infusion of Intrathecal Ketamine for Chronic Pain: A Case Report

Ketamine, a selective, noncompetitive N-methyl- d-aspartate (NMDA)-receptor antagonist, is able to alter pain perception at the spinal level. Little clinical data exist on the intrathecal and epidural use of ketamine in chronic pain. Histopathologic findings after intrathecal injection of ketamine with and without preservatives are rarely reported. This outcome was evaluated in a 72-year-old woman with abdominal pain due to cancer who was treated with the intrathecal application of bupivacaine, clonidine, and morphine. We reached satisfactory pain relief with the addition of ketamine to the mixture for 7 days. On postmortem, focal lymphocytic vasculitis close to the catheter injection site was found. This finding has not been described previously after long-term application of ketamine intrathecally. The intrathecal infusion of ketamine with preservative, or the mixture of ketamine, clonidine, morphine, and bupivacaine resulted in isolated lymphocytic vasculitis of the spinal cord and leptomeninges without any clinical signs of neurological deficit.

Ketamine in Chronic Pain: A Review

Ketamine is a dissociative anaesthetic agent that has been used clinically for a wide range of indications for over 25 years. Recently there has been interest in the mechanism of its analgesic effect and its utility in the treatment of pain caused by chronic disease, especially neuropathic pain. Despite the popularity of ketamine as a single oral dose especially in paediatric analgesia, the drug has not often been given orally on a continuous basis for any indication. This article reviews the published evidence for ketamine in chronic pain.