title: Effectiveness of a heated lidocaine/tetracaine topical patch for pain associated with myofascial trigger points: results of an open-label pilot study.
abstract: OBJECTIVE
  Evaluate potential usefulness of a heated lidocaine/tetracaine topical patch for treatment for pain associated with myofascial trigger points (MTPs).
  
  
  BACKGROUND
  Depth and duration of analgesia when patch is used as indicated, on intact skin to provide local dermal analgesia for superficial venous access and dermatologic procedures, suggest utility in relief of MTP-associated pain.
  
  
  METHODS
  In this open-label, single-center outpatient pilot study, patients with ≥ 1-month history of pain associated with up to 3 MTPs and average pain intensity ≥ 4 on 11-point scale applied 1 patch to each MTP for 4 hours twice daily for 2 weeks, followed by 2 weeks with no treatment. Patients continued prescribed analgesic dosing regimens.
  
  
  RESULTS
  Twenty patients enrolled; 17 completed the study. At baseline, mean ± SD average pain intensity was 6.3 ± 1.56. This decreased by 33% to 4.5 ± 2.31 (N = 20) at the end of treatment; 40% of patients had clinically significant (≥ 30%) decrease, and 25% had substantial (≥ 50%) decrease. Pain interference with general activity, mood, normal work, and enjoyment of life decreased by ≥ 50% in 35% of patients; and with walking, sleep, and relationship by ≥ 50% in 50% of patients (N = 20). Worst trigger point sensitivity improved in 45% of patients; 75% were satisfied or very satisfied with treatment; none required rescue medication. Two weeks after stopping treatment, average pain intensity was 5.0 ± 2.04; treatment benefit was maintained in 8 (40%) patients. The most common adverse event was erythema.
  
  
  CONCLUSIONS
  The heated lidocaine/tetracaine patch has potential utility as a noninvasive pharmacologic approach for managing MTP pain. Further studies are warranted.
authors.affiliation: Carolinas Pain Institute, Winston-Salem, North Carolina 27103, USA. RRauck@ccrpain.com
authors.forename: Richard
authors.initials: R
authors.lastname: Rauck
authors.forename: Michael
authors.initials: M
authors.lastname: Busch
authors.forename: Thomas
authors.initials: T
authors.lastname: Marriott
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004338:Drug Combinations; D005260:Female; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009209:Myofascial Pain Syndromes / Q000517:prevention & control*; D010865:Pilot Projects; D013748:Tetracaine / Q000008:administration & dosage*; D057968:Transdermal Patch; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D004338:Drug Combinations; D013748:Tetracaine; D008012:Lidocaine