Topically Administered Ketamine Reduces Capsaicin-Evoked Mechanical Hyperalgesia

  title={Topically Administered Ketamine Reduces Capsaicin-Evoked Mechanical Hyperalgesia},
  author={Reino P{\"o}yhi{\"a} and Anneli Vainio},
  journal={The Clinical Journal of Pain},
Background:The n-methyl-d-aspartate receptor antagonists such as ketamine relieve chronic pain but their oral and parenteral use is limited by the adverse effects. Experimental studies indicate that the peripheral n-methyl-d-aspartate receptors are involved in nociception. Recent clinical findings suggest that ketamine gel alleviates neuropathic pain, but no placebo-controlled randomized studies are available on the neurosensory effects of ketamine gel in experimental neurogenic pain… 
Evaluation of Anti-Hyperalgesic and Analgesic Effects of Two Benzodiazepines in Human Experimental Pain: A Randomized Placebo-Controlled Study
The results are suggestive for a possible anti-hyperalgesic effect of drugs acting at the GABAA-receptors in humans, particularly in models of secondary hyperalgesia and deep pain.
Topical and Peripheral Ketamine as an Analgesic
  • J. Sawynok
  • Biology, Medicine
    Anesthesia and analgesia
  • 2014
Topical analgesics are likely more effective in particular conditions (patient factors, disease factors), and future trials of topical ketamine should include a consideration of factors that could predispose to favorable outcomes.
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The present literature review aimed to provide insight into the sensitivity of different hyperalgesia and allodynia models of pharmacological treatment and raised questions about the translatability of these models to the treatment of neuropathic pain.
Assessing efficacy of non-opioid analgesics in experimental pain models in healthy volunteers: an updated review.
This review addresses how the efficacy of non-opioid analgesics have been assessed in human volunteers using experimental pain models to evaluate the mechanisms and pharmacokinetics of analgesics.
Transdermal Ketamine and S(+)-Ketamine as Adjuvants Following Orthopaedic Surgery under Bupivacaine Spinal Anaesthesia
Transdermal 25 mg ketamine or 25 mg S(+)- ketamine similarly prolonged the duration of analgesia following orthopaedic procedures under bupivacaine spinal blockade, demonstrated by clinical and laboratorial data.
Topical high-concentration (40%) menthol-somatosensory profile of a human surrogate pain model.


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Peripheral Analgesic Effects of Ketamine in Acute Inflammatory Pain
Ketamine infiltration had brief local analgesic effects, but several measures of pain and hyperalgesia were unaffected, therefore, a clinically relevant effect of peripheral ketamine in acute pain seems unlikely.
The effects of intradermal fentanyl and ketamine on capsaicin-induced secondary hyperalgesia and flare reaction.
Fentanyl inhibits neuropeptide release on peripheral application without modulating secondary hyperalgesia and axon-reflex flare, and ketamine failed to inhibit both secondary hyperAlgesia or axon reflex flare as long as nonlocal anesthetic concentrations were applied.
Analgesic Effects of Ketamine Ointment in Patients With Complex Regional Pain Syndrome Type 1
Topical application of KET appears to be beneficial for the patients with acute early dystrophic stage of CRPS I because of either its local anesthetic effect or NMDA receptor antagonist action.
A Pilot Study Examining Topical Amitriptyline, Ketamine, and a Combination of Both in the Treatment of Neuropathic Pain
This pilot study demonstrated a lack of effect for all treatments in the 2 day double blind placebo controlled trial, followed by analgesia in an open label trial in a subgroup of subjects who chose to use the combination cream for 7 days.
High‐dose oral dextromethorphan versus placebo in painful diabetic neuropathy and postherpetic neuralgia
It is concluded that dextromethorphan or other low-affinity NMDA channel blockers may have promise in the treatment of painful diabetic neuropathy.
Concentration‐Effect Relationships for Intravenous Alfentanil and Ketamine Infusions in Human Volunteers: Effects on Acute Thresholds and Capsaicin‐Evoked Hyperpathia
Experimental human pain models may be used to study analgesic pharmacology and may serve as important methods for defining the analgesic efficacy of drugs in phase I clinical trials.