When the pain decreased, her troubles began

• has no active metabolites, which decreases the risk of hepatic side effects
  
• offers a high volume of distribution, thus allowing clinical effect with minimal dosing.
  

Oral methadone is a strong analgesic—20 mg is as potent as 100 mg of oral morphine. Start methadone at 5 to 10 mg bid or tid for chronic pain management and titrate according to clinical response and tolerability.^10-12
Beware the potential for addiction when prescribing opioids to any patient.^13,14 The U.S. Drug Enforcement Agency classifies both methadone and fentanyl as schedule II substances, which applies to highly addictive medications with FDA-approved indications. See patients at least biweekly, especially when switching or titrating pain medications, and watch closely for signs of overuse or addiction. Inform patients to:

• watch for symptoms such as oversedation, memory and concentration problems, and sudden changes in personality
  
• call you to clarify if these symptoms are methadone side effects.
  

Increase methadone by 5 mg every 3 to 4 days based on patient tolerance and response. If side effects decrease function or treatment response is lacking, consider a different opioid or another treatment. Decrease visit frequency to once monthly when the pain is under control and the patient experiences no side effects.

Watch for other potential side effects of methadone, such as constipation, sedation, breakthrough pain, sexual dysfunction, decreased immunity, respiratory depression, or prolonged corrected QT intervals.

Patients usually tolerate an immediate switch from transdermal fentanyl to methadone, but a sudden switch from high-dose fentanyl can reduce methadone’s effectiveness. Starting methadone at a high dosage to compensate for loss of effectiveness could increase side effect risk. If the fentanyl dosage exceeds 100 mcg/hr, taper by 25 mcg weekly. Simultaneously start methadone at a low dosage and titrate by 5 to 10 mg weekly as needed.

Table 2

Chronic pain management in the elderly: Dos and don’ts

DO
Use self rating scales, as patient can gauge his/her own pain most accurately
Consider nonpharmacologic treatments and nonnarcotic analgesics first
Watch closely for side effects and drug-drug/drug-disease interactions in patients receiving analgesics long-term
Monitor patients receiving opioids long-term for oversedation, changes in cognition and function
Consider switching to methadone or another opioid if patient cannot tolerate current opioid regimen
DO NOT
Prescribe propoxyphene or meperidine—which carry a higher risk of adverse effects than other opioids—to older patient
Prescribe opioids if the medical history is unclear
Increase opioid dosages without seeing the patient

TREATMENT Medication change

We stop transdermal fentanyl and start oral methadone, 5 mg bid, while continuing oxycodone/acetaminophen at the previous dosage.

Two days later, Mrs. M is much more alert. Since admission 1 week ago, her sedation rating has improved from 3 (mildly sedated) to 4 (almost fully alert). She rates her pain as mild and reports no breakthrough pain or other side effects from methadone. Her MMSE score has improved to 24—suggesting close to normal cognition—and she is much more interactive with staff and family.

Eight days after we start methadone, we stop oxycodone/acetaminophen and increase methadone to 10 mg bid to further improve cognition and alertness and to see if 1 pain medication is suffcient. Two days later, we discharge Mrs. M. She is fully alert, feels little or no joint pain, and is tolerating the methadone increase.

At outpatient follow-up 4 weeks later, Mrs. M remains pain-free and her MMSE score is 29, suggesting normal cognition. Over 8 months, we continue to see her monthly and then bi-monthly, after which we refer her to her primary care physician.

Related resources

• American Association for Geriatric Psychiatry. www.aagponline.org.
  
• American Pain Society. www.ampainsoc.org.
  

Drug brand names

• Alprazolam • Xanax
  
• Clonazepam • Klonopin
  
• Fentanyl (transdermal) • Duragesic
  
• Hydromorphone • Dilaudid
  
• Meperidine • Demerol
  
• Methadone • Dolophine
  
• Oxazepam • Serax
  
• Oxycodone • OxyContin, Roxicodone
  
• Oxycodone/acetaminophen • Percocet
  
• Propoxyphene • Darvon
  
• Sertraline • Zoloft
  

Disclosure

The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.