CASE 1: OPIOID ROTATION

Objectives

  1. Describe the risk of analgesic nephropathy, uncontrolled hypertension and drug-drug interactions with the use of acetaminophen containing medications.
  2. Discuss appropriate choice of analgesic medications
  3. Demonstrate appropriate doses at which to rotate to a second opioid medication when discontinuing another opioid medication.

Readings

1.Nalamachu, S. Opioid rotations in clinical practice. Adv Ther. 2012;29(10):849-863. Adv Ther. 2012 Oct;29(10):849-863.

2.Arnold R., WeissmanDE. Calculating Opioid Dose Conversions, 2nd Edition. Fast Facts and Concepts. July 2005; 36. Available at: April 24, 2013.

3.WeissmanDE. Opioid Dose Escalation, 2nd Edition. Fast Facts and Concepts. July 2005; 20. Available at: Accessed April 24, 2013.

The Case:

Rose is a 66 year old woman with a past medial history of hypertension, non-insulin requiring diabetes mellitus, chronic renal insufficiency (baseline creatinine 1.9), atrial fibrillation for which she is on coumadin, osteoarthritis involving multiple joints and chronic low back pain.

For the last 3 months she has reported distal lower extremity pain which she describes as burning, increasing in frequency and severity, distinct from her low back pain, exacerbated by exercise and partially relieved by oxycodone 5/325, using 8 tablets/day. Prior to this exacerbation she had been using 3 tablets/day.

Her blood pressurewas previously ≤130/90 and is now 146/96. Her physical examination is significant for point tenderness over L4 &:L5, without paravertebrael spasm or pain on straight leg elevation, and she has reduced range of motion of the lumbar spine and hips. She has symmetrically reduced pulses throughout her bilateral lower extremities. She has inconsistent loss of pinprick and light touch discrimination in both lower extremities and reduced proprioception at both heals.

On monitoring of usual laboratory tests her INR has now decreased from her usual 2.2 to 1.8. The serum creatinine has increased from 1.9 to 2.2.

Question 1

The patients uncontrolled hypertension, worsening renal status and suboptimal INR can be accounted for by:

a.Renal Artery Stenosis

b.Medication non-compliance

c.Increased oxycodone/APAP use

d.Analgesic tolerance

The Case Continues

The patient indicates that she is reluctant to consider any further surgical procedures for herdegenerative disc disease and osteoarthritis. She states that she is increasing her usage of opioids because of lessening effect and shorter duration of action of the oxycodone/APAP.

Question 2

In addition to consideration of further medical work-up you decideto:

  1. Counsel the patient about your concerns that she has become psychologically dependent on her medications
  2. Discontinue oxycodone/APAP because you believe she is addicted to opioid medications
  3. Discontinue oxycodone/APAP because she is non compliant with her medical care
  4. Consider starting a long acting opioid medication

Please explain your answer:______

The Case Continues

The patient and doctor agree to conservative management following an MRI of the spine which reveals multiple level disc herniations with canal and neuroforaminal compression. They agree that a trial of a long acting opioid medication would be appropriate.

However his insurance company does not cover the long acting formulation of oxycodone (Oxycontin).It does cover MSContin and Kadian (Long acting morphine formulations) Duragesic (Long acting fentanyl formulation) and methadone.

Question 3

The best choice of pain medication for this patient would be

  1. Methadone
  2. Morphine
  3. Fentanyl transdermally
  4. Long acting meperidine

Please explain your answer:______

The Case Continues

You discuss starting a Transdermal Fentanyl patch after explaining that it will take 6 hours for the patient to notice the onset of analgesia and 12 to 24 hours to reach a consistent level of analgesia. In addition to educating the patient about the need to vary where they apply the patch and to date each application that they will need to change it every 72 hours (approximately 15% of patients will need to change it every 48 hours). You write a prescription for Transdermal Fentanyl.

Question 4

The best dose of Transdermal Fentanyl would be

  1. 100 MCG q 48 hours
  2. 100MCG q72 hours
  3. 50MCG q72 hours
  4. 25 MCG q72 hours

Please explain your answer:______

What short-acting medication and dose would you choose for breakthrough medication in this patient?:______

The Case Concludes

The patient starts the new regimen along with a stool softener and laxative to manage opioid-associated constipation. The patient is happy with this regimen, has improved pain control and no side effects other than mild constipation.

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