When starting a patient on a new opioid, or switching the patient from one opioid to another, the clinician should carefully monitor for side effects of both the drug and its metabolites. The direct side effects and side effects from metabolites of most opioids are similar ( Table 2 ). Direct side effects usually appear early on in therapy and often improve over time. In contrast, adverse effects from metabolites often have a more insidious onset, related to their slow accumulation.
Some health care professionals are reluctant to prescribe opioids for patients with advanced end-stage disease, particularly when there is a potential for respiratory compromise. Therapeutic doses can reduce respiratory rate and depth, but the resulting hypercarbia from mild hypoventilation stimulates central chemoreceptors, leading to a compensatory increase in respiratory rate to maintain arterial oxygen levels. When properly titrated, these drugs are safe for this population.
Morphine, hydromorphone, oxycodone, and codeine belong to one class of opioids called phenanthrenes. Fentanyl and meperidine belong to another class known as phenylpiperidines. Although genuine allergies to opioids are rare, in the case where there is a documented allergy, an opioid with another chemical structure should be chosen.
Geriatrics and Aging. 2009;12(1):48-52. © 2009 1453987 Ontario, Ltd.
Cite this: Prescribing Opioids to Older Adults: A Guide to Choosing and Switching Among Them - Medscape - Jan 01, 2009.