title: A Novel Compound Analgesic Cream (Ketamine, Pentoxifylline, Clonidine, DMSO) for Complex Regional Pain Syndrome Patients.
abstract: BACKGROUND
  Evidence suggests that complex regional pain syndrome (CRPS) is a manifestation of microvascular dysfunction. Topical combinations of α2-adrenergic receptor agonists or nitric oxide donors with phosphodiesterase or phosphatidic acid inhibitors formulated to treat microvascular dysfunction have been shown to reduce allodynia in a rat model of CRPS-I. Driven by these findings, we assessed the outcomes of CRPS patients treated with a compound analgesic cream (CAC) consisting of ketamine 10%, pentoxifylline 6%, clonidine 0.2%, and dimethyl sulfoxide 6% to 10%.
  
  
  METHODS
  An audit was conducted on 13 CRPS patients who trialed the CAC. A detailed report was compiled for each patient which comprised baseline characteristics, including CRPS description, previous treatments, and pain scores (numerical pain rating scale; 0 to 10). Recorded outcomes consisted of pain scores, descriptive outcomes, and concurrent medications/treatments, for which basic analysis was performed to determine the effectiveness of the CAC. Case reports are presented for 3 patients with varying outcomes.
  
  
  RESULTS
  Nine patients (69%) reported pain/symptom reduction (4.4 ± 2.1 vs. 6.3 ± 1.9) with use of the CAC. Six patients reported sustained benefits after 2 months of CAC use, and 2 patients reported complete resolution of pain/symptoms: one had early CRPS-I and the other received a partial CRPS diagnosis. An otherwise medication refractory and intolerant patient found partial benefit with the CAC.
  
  
  CONCLUSIONS
  These results demonstrate promise for this topical combination as a useful treatment in multimodal therapy for patients with CRPS, with the potential to resolve pain/symptoms in early CRPS patients.
authors.affiliation: Hunter Pain Clinic, Broadmeadow, New South Wales, Australia.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Russo
authors.affiliation: Hunter Pain Clinic, Broadmeadow, New South Wales, Australia.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Santarelli
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000700:Analgesics / Q000008:administration & dosage* / Q000627:therapeutic use*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D002422:Causalgia / Q000188:drug therapy; D003000:Clonidine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D020918:Complex Regional Pain Syndromes / Q000188:drug therapy*; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009824:Ointments; D010147:Pain Measurement; D010431:Pentoxifylline / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D012019:Reflex Sympathetic Dystrophy / Q000188:drug therapy; D016896:Treatment Outcome
chemical_list: D000316:Adrenergic alpha-Agonists; D000700:Analgesics; D000778:Anesthetics, Dissociative; D000891:Anti-Infective Agents, Local; D009824:Ointments; D010726:Phosphodiesterase Inhibitors; D007649:Ketamine; D003000:Clonidine; D010431:Pentoxifylline; D004121:Dimethyl Sulfoxide
keywords: NO donor; clonidine; complex regional pain syndrome; dimethyl sulfoxide; ketamine; nitric oxide complex regional pain syndrome; pentoxifylline; topical analgesic