Transdermal pain management Yousuf Zafar, MD Duke Cancer Care Research Program.

Transdermal pain management

Yousuf Zafar, MDDuke 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

Mechanism of actionµ-opioid receptor

µ

µµ

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 avoidedMuijsers RBR, Wagstaff AJ. Drugs 2001

First-pass effect

First-pass effect

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

Delayed onset of pain control.

Delay for dosage adjustments to take effect

Patch size and skin surface area availability

Disadvantage to transdermal fentanyl use

Muijsers RBR, Wagstaff AJ. Drugs 2001

Beyond fentanylCompounded transdermals

Latta KS. J Pain Pall Care Pharm 2002

Compounding – preparation of medication for a specific patient

Useful for preparing administration routes not readily available

Must be prepared by accredited compounding pharmacy

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 ineffectiveHo 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 analgesiaPolomano 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 [email protected]