1. Opioids Safe and Effective for the Elderly
Opioid therapy may be underutilized in the elderly. Older patients may be less likely than younger patients to complain of pain or to accept opioid analgesics because they fear addiction; they associate opioids (particularly morphine) with severe or terminal illness, and they fear that complaining about pain may lead to investigations or hospitalization (Robinson 2007). Also, some physicians are reluctant to prescribe opioids for elderly patients.
While older patients are less likely to complain about pain, they appear to have the same pain thresholds as younger patients. It is known that elderly patients have comparable pain levels to younger ones, and that the dose of morphine necessary to achieve pain VAS1 < 4 is not significantly affected by age (Wilder-Smith 2005).
Opioids are generally safe in the elderly if carefully titrated. As a class, opioids cause less organ toxicity than NSAIDs, and in single-dose studies, they appear to cause less cognitive impairment than benzodiazepines (Hanks 1995). Clinics caring for elderly patients with well-defined pain conditions have found very low rates of abuse and addiction (Ytterberg 1998, Mahowald 2005).
2. Risks for the Elderly
2.1 Risks for the Elderly
1. Overdose: Several pharmacokinetic factors put the elderly at higher risk for opioid overdose than younger patients, including lower serum binding, lower stroke volume (slows liver metabolism), and greater sensitivity to the psychoactive and respiratory effects of opioids; (Freye 2004, Wilder-Smith 2005).
2. Oversedation: A high proportion of elderly patients on opioids are also on benzodiazepines and other psychotropic medications (Hartikainen 2005), increasing the risk of sedation.
2.2 Reducing Risks for the Elderly
- Educate the patient and caregiver about signs of overdose, e.g., slurred or drawling speech, emotional lability, ataxia, “nodding off” during conversation or activity (see Table B-5.2: Opioid Risks).
- Avoid opioids in cognitively impaired patients living alone, unless ongoing medication supervision can be organized.
- Consider a three-day “tolerance check:” contact the patient three days after starting the prescription to check for any signs of sedation.
- Monitor renal function (creatinine and creatinine clearance) (Pergolizzi 2008).
3. Prescribing Cautions for the Elderly
Suggested prescribing recommendations for the elderly are as follows:
- Start initial titration at no more than 50% of the suggested initial dose for adults, and lengthen the time interval between dose increases. (See Table B-9.1: Opioid Suggested Initial Dose and Titration.)
- Among strong opioids, oxycodone and hydromorphone may be preferred over oral morphine for the elderly because they are less likely to cause constipation and sedation (Clark 2004).
- Controlled-release (CR) formulations are recommended for the elderly for reasons of compliance even though there is no evidence CR formulations are more effective than immediate-release (IR) formulations. However, for breakthrough pain or activity-related pain, IR formulations can be used (Pergolizzi 2008).
- Morphine solutions are preferable to tablets in some situations, e.g., patients with swallowing problems, or patients requiring less than 5 mg morphine per tablet (Pergolizzi 2008).
- For elderly patients on benzodiazepines, try to taper the benzodiazepine dose to reduce the risk of falls and cognitive impairment.
R17. Summary of Peer-Reviewed Evidence
1. Evidence suggests that many elderly patients who might benefit from opioid therapy are not receiving it.
A national Canadian survey documented that 29% of Canadian adults experienced chronic pain, with increasing frequency in elderly patients (Moulin 2002). Although most of these patients had moderate to severe pain that interfered with function, only 7% were receiving opioids stronger than codeine. In a study of 83,000 patients in 12 primary-care clinics in Wisconsin, only 201 patients were receiving opioid therapy for chronic pain (Adams 2001). Another survey found that up to 35% of primary-care physicians in Canada would never prescribe opioids even for moderate to severe chronic pain (Morley-Forster 2003). Solomon et al. described prescription opioid use among elderly with arthritis and low back pain. They found that elderly patients most commonly receive weak opioids, and rarely strong opioids (Solomon 2006).
2. Controlled-release opioids are preferred for the elderly for reasons of compliance.
“Consensus Statement of an International Expert Panel with Focus on the Six Clinically Most Often Used World Health Organization Step III Opioids” recommends a preference for sustained-release preparations because they increase patient compliance, as dosing frequency can be reduced. Patients should also be prescribed short-acting analgesics for the treatment of breakthrough pain. This recommendation is despite the fact that there is no evidence to support the use of long-acting analgesics over short-acting analgesics (Pergolizzi 2008).
3. Morphine solutions may be used in some situations.
The consensus statement of the International Expert Panel recommends that morphine solutions are a better option than tablets for p.r.n. (as needed) use. If the patient is frail and/or elderly, a low dose, e.g., 5 mg 4-hourly (or less), will help to reduce the likelihood of drowsiness, confusion or unsteadiness (Pergolizzi 2008).