| Literature DB >> 23355774 |
Abstract
The elderly population is projected to make up 20% of the total United States population by the year 2030. In addition, epidemiological data suggests increasing prevalence of chronic pain and frailty with advancing age. Pain, being a subjective symptom, is challenging to manage effectively. This is more so in elderly populations with age-specific physiological changes that affect drug action and metabolism. Elderly patients are also more likely to have multiple chronic health pathologies, declining function, and frailty. The barriers present for patients, providers, and health systems also negatively impact efficient and effective pain control. These factors result in disproportionate utilization of health resources by the older population group. The scientific literature is lagging behind in age-specific studies for the elderly population. As a result, there is a lack of age-specific standardized management guidelines for various health problems, including chronic pain. Increasing efforts are now being directed to studies on pain control in the elderly. However, pain management remains inconsistent and suboptimal. This article is an attempt to suggest an informed, comprehensive guide to achieve effective pain control in the presence of these limitations.Entities:
Keywords: chronic pain; elderly; frailty; geriatric pain
Mesh:
Substances:
Year: 2013 PMID: 23355774 PMCID: PMC3552607 DOI: 10.2147/CIA.S30165
Source DB: PubMed Journal: Clin Interv Aging ISSN: 1176-9092 Impact factor: 4.458
Physiologic changes with aging and its effects
| System | Changes | Effect | Effect of drug use |
|---|---|---|---|
| Gastrointestinal | Altered secretions | Altered drug absoption | Altered oral bioavailability |
| Decreased blood flow | Altered bioavailability | ||
| Altered motility | Altered transit time | ||
| Altered absorptive surface | |||
| Liver | Small liver mass | Decreased serum albumin | Increased bioavailability |
| Reduced hepatic blood flow | Decreased metabolism of drugs | Higher toxicity risk | |
| Decreased hepatic enzymes | by 30%–40% | ||
| (oxidation and cytochrome p-450) | |||
| Decreased protein synthesis | |||
| Decreased regeneration rate | |||
| Cardiac | Decreased cardiac index | Rapid and high drug peak | Higher toxicity risk |
| Renal | Reduced size | Decreased renal elimination | Required dose adjustment |
| Decreased renal blood flow | |||
| Reduced renal function (gfr), | |||
| 1% per year after age 50 | |||
| General | Increased body fat | Increased volume of distribution | Delayed elimination and onset |
| Decreased body water | for lipophilic medication | of drug of action | |
| Increased plasma concentration of hydrophilic drugs | Higher frequency of side effects | ||
| Nervous system | Decreased cerebral blood flow | Decreased descending inhibitory | Increased pain with noxious stimuli |
| Neuronal loss/atrophy | pain control and altered | Altered response to pain | |
| Decreased synthesis of neurotransmitters Decreased opioid receptor density | pain processing | ||
| Muscle | Decreased muscle mass | Decreased functioning |
Abbreviation: gfr, glomerular filtration rate.
Figure 1Management of pain in frail older adults.
Abbreviation: NSAID, nonsteroidal anti inflammatory drug.
Opioid equianalgesic conversion table
| Elimination | IV equivalent to IV morphine | PO equivalent to IV morphine | |
|---|---|---|---|
| (t½) in hours | 10 mg (single dose) | 10 mg (single dose) | |
| Morphine | 2–4 | 10 mg | 20–60 mg |
| Fentanyl | 4 | 100 mcg | N/A |
| Hydrocodone | 4 | N/A | 30–40 mg |
| Oxymorphone | 2–3 | 1 | 10 |
| Hydromorphone | 3 | 2 mg | 10 mg |
| Methadone | 20–120 | 10 mg | 10–20 mg |
| Oxycodone | 3 | N/A | 20–30 mg |
Notes
very long elimination time causes methadone to accumulate over many days.
Abbreviations: IV, intravenous; PO, oral; N/A, not applicable.