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Transdermal pain management. Yousuf Zafar, MD Duke Cancer Care Research Program. Case. 68yo woman with pancreatic cancer Abdominal pain controlled with 30mg Oxycontin q12hr Interested in decreasing number of pills, and heard about “pain patch” Started on 25mcg transdermal fentanyl
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Transdermal pain management Yousuf Zafar, MD Duke Cancer Care Research Program
Case • 68yo woman with pancreatic cancer • Abdominal pain controlled with 30mg Oxycontin q12hr • Interested in decreasing number of pills, and heard about “pain patch” • Started on 25mcg transdermal fentanyl • Two days later, her pain is unbearable • Switched back to oral analgesics
Outline • How transdermal fentanyl works • How to use transdermal fentanyl • Moving beyond transdermal fentanyl
Mechanism of action Muijsers RBR, Wagstaff AJ. Drugs 2001
fentanyl Mechanism of actionµ-opioid receptor µ µ µ
Advantages of transdermal pain management • Useful for patients who are unable to swallow or patients experiencing nausea/vomiting • Useful for patients with poor IV access • Constant plasma concentrations • First-pass metabolism is avoided Muijsers RBR, Wagstaff AJ. Drugs 2001
Dosing transdermal fentanyl • Calculate previous 24hr analgesic requirements • Convert to oral morphine dose • Convert 24hr oral morphine dose to transdermal fentanyl dose • Titrate every 3 days until pain is controlled • May take up to 6 days to achieve steady-state concentrations • Continue breakthrough medication
Examples • Patient 1: 30mg Oxycontin q12hr = 60mg/day • 60mg x 1.5 = 90mg/day oral morphine • Oral morphine:transdermal fentanyl = 2:1 • 45mcg/hr fentanyl ≈ 50mcg/hr fentanyl q72hr Skaer TL. Health Quality Life Outcomes 2006
Johns Hopkins Opioid Program hopweb.org
Examples • Patient 2: 20mg/day oral hydromorphone, inadequate pain relief • Morphine:hydromorphone = 4:1 • 80mg/day oral morphine • 2 morphine:1 fentanyl = 40mcg/hr • Inadequate pain control, so round up to 50mcg/hr
Patch application considerations • Clean, dry skin • Clipped (not shaved) hair • After placing, hold in place for 30 seconds • Rub the top of patch for 3 minutes • Alternate patch sites • Avoid heating pads/electric blankets as heat can increase rate of release Skaer TL. Health Quality Life Outcomes 2006
Disadvantage to transdermal fentanyl use • Delayed onset of pain control. • Delay for dosage adjustments to take effect • Patch size and skin surface area availability Muijsers RBR, Wagstaff AJ. Drugs 2001
Beyond fentanylCompounded transdermals • Compounding – preparation of medication for a specific patient • Useful for preparing administration routes not readily available • Must be prepared by accredited compounding pharmacy Latta KS. J Pain Pall Care Pharm 2002
Topical morphine • Not extensively studied • Primarily used for cutaneous pain from tumor infiltrating skin • Painful ulcers • Limited stability in topical formulations Donnelly S et al. Supp Care Cancer 2002
Transdermal lidocaine and amitriptyline • Amitriptyline: tricyclic antidepressant used for neuropathic pain • Study compared topical amitriptyline to topical lidocaine or placebo for neuropathic pain • 35 patients • Topical lidocaine reduced pain intensity compared to placebo minimally • Amitriptyline was ineffective Ho KY et al. Clin J Pain 2008
Potential transdermal compounded drugs • Topical hydromorphone • Swish-and-spit hydromorphone • Rectal lidocaine • Ativan, benadryl, Haldol, Reglan (ABHR) cream for nausea
Fentanyl via transdermal iontophoresis • Patient-controlled transdermal system • Allows for delivery of charged molecules across intact skin using electric current • On-demand button delivers fentanyl • Studies have shown PCTS to be comparable to morphine PCA • No IV interruptions/alarms, catheter-related problems • Fewer gaps in analgesia Polomano RC et al. J PeriAnesthesia Nurs 2008
Conclusions • Transdermal fentanyl is a useful alternative to PO/IV opioid analgesics • Monitor patients during titration period to ensure adequate pain control • Think outside the box – consult compounding pharmacist for patients with special pain control needs
Resources • Johns Hopkins opioid program – hopweb.org • Ken Latta, BS, RPh – Manager, Duke Compounding Facilitylatta001@mc.duke.edu