Topical Morphine for Analgesia in Patients With Skin Grafts

Condition(s) targeted: Skin Transplantation; Pain

Intervention: morphine (Drug)

Phase: Phase 3

Status: Not yet recruiting

Sponsored by: Rambam Health Care Campus

Official(s) and/or principal investigator(s):
Yehuda Ullman, M.D., Principal Investigator, Affiliation: Rambam Health Care Campus

Overall contact:
Yehuda Ullman, M.D., Phone: +972-4-8542974, Email: y_ullmann@rambam.health.gov.il

The management of pain endured by patients after skin grafting is complex. Pain is the single most distressing symptom but as it is difficult to manage, it is often under-treated. These patients may experience pain from two types of wound: the original injury and from “skin-donor” sites, areas of healthy skin from which skin is surgically removed and used to cover the original injury. As the section of skin which is removed is standardized, the wound created at the donor site is uniform and so provides a model of an acute wound.

Opioids (such as morphine) are the backbone of treating the moderate to severe pain experienced by any patient. But due to their potentially severe side effects and that some patients do not experience sufficient relief from the treatment, optimal treatment schedules are still being sought after.

Topically applied morphine has provided effective and safe analgesia in several clinical models. We, therefore, wish to apply this treatment modality onto skin-graft donor wounds. If found to be effective this could be an appealing non-invasive method to treat the pain of this type of wound.

Official title: Topical Morphine for Analgesia in Patients With Skin Grafts

Study design: Treatment, Randomized, Double-Blind, Placebo Control, Parallel Assignment, Safety/Efficacy Study

Primary outcome: Sum of the differences in pain scores between the skin-donor site vs. original injury site taken over a 24 hour period after application of the medication.

Secondary outcome:

Pain score at skin-donor site using an abbreviated form of the McGill Pain Questionnaire

time course of analgesia for each drug concentration

presence and severity of side effects: (a) central (nausea, vomiting, sedation, purities) and (b) local (burning, tingling, wheal, flare)

supplementary analgesic medications

Detailed description: Administration of morphine into the knee joint is the best-studied clinical procedure documenting the use of topically-applied opioids. When 1-5 mg morphine were injected into the knee joint, patients experienced pain relief for up to 24 hours, whereas similar doses given systemically (i. e. intravenously) were effective for 2-4 hours. Furthermore, the analgesic effect was reversed when the opioid antagonist naloxone was injected into the knee joint. Both these findings indicate that the effect is mediated by local opioid receptors in the knee joint.

Peripheral analgesic effects of opioids are not detectable in normal tissue but appear minutes to hours after initiation of inflammation. This suggests that opioid receptors are already present in the peripheral nerve terminals but under normal conditions they are not functional.

Research on application of opioids to skin wounds is very sparse and has primarily been performed in palliative care patients. These reports demonstrate that topical opioid gel (morphine or diamorphine) provided rapid and effective relief. In some patients pain subsided within 20 minutes after application with a long-lasting (7-8 hours) effect. Fundamental aspects regarding topical application of opioids onto skin wounds are still lacking. For example, issues such as optimal dose and dose-effect relationships have not been investigated. We hope to determine these in this study.

Minimum age: 18 Years. Maximum age: 75 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Patients undergoing skin-grafting

- American Society of Anesthesiologists (ASA) classification I-II

- Written consent

- Either sex

- Able to self-asses and report their pain level

Exclusion Criteria:

- Alcohol abuse or addiction - current

- Opioids and benzodiazepines abuse – life time

- Known hypersensitivity to morphine

- Major renal or hepatic dysfunction

- Pregnancy or lactation

- Sleep-apnoea-syndrome

- Diabetes

- Participation in other clinical studies

Yehuda Ullman, M.D., Phone: +972-4-8542974, Email: y_ullmann@rambam.health.gov.il

Department of Plastic Surgery, Rambam Medical Center, Haifa 31096, Israel

Related publications:

Krajnik M, Zylicz Z, Finlay I, Luczak J, van Sorge AA. Potential uses of topical opioids in palliative care--report of 6 cases. Pain. 1999 Mar;80(1-2):121-5.

Stein C, Comisel K, Haimerl E, Yassouridis A, Lehrberger K, Herz A, Peter K. Analgesic effect of intraarticular morphine after arthroscopic knee surgery. N Engl J Med. 1991 Oct 17;325(16):1123-6.

Porzio G, Aielli F, Verna L, Cannita K, Marchetti P, Ficorella C. Topical morphine in the treatment of painful ulcers. J Pain Symptom Manage. 2005 Oct;30(4):304-5. No abstract available.

Ribeiro MD, Joel SP, Zeppetella G. The bioavailability of morphine applied topically to cutaneous ulcers. J Pain Symptom Manage. 2004 May;27(5):434-9.

Stein A, Yassouridis A, Szopko C, Helmke K, Stein C. Intraarticular morphine versus dexamethasone in chronic arthritis. Pain. 1999 Dec;83(3):525-32.

Zeppetella G, Ribeiro MD. Morphine in intrasite gel applied topically to painful ulcers. J Pain Symptom Manage. 2005 Feb;29(2):118-9. No abstract available.

Stein C, Schafer M, Machelska H. Attacking pain at its source: new perspectives on opioids. Nat Med. 2003 Aug;9(8):1003-8. Review.

Starting date: November 2006
Last updated: August 8, 2006