Of special note, methadone should not be the first choice for ER/LA opioid due to its unique long half-life and ability to prolong the QT interval.34 Only clinicians familiar with its use should prescribe methadone, while referring to the drug’s clinical practice guideline for further advice.
At the start, prescribe the lowest effective dosage (referring to the product labeling for guidance) and calculate total daily dose in terms of morphine milligram equivalents (MME) (TABLE 335-37).28 Exercise caution when considering opioids for patients with respiratory sleep disorders and for patients ≥ 65 years due to altered pharmacokinetics in the elderly population.38 Also make dose adjustments for renal and hepatic insufficiency (TABLE 435).
Doses between 20 to 50 MME/d are considered relatively low dosages.28 Be cautious when prescribing an opioid at any dosage, and reassess evidence of individual benefits and risks before increasing the dosage to ≥ 50 MME/d.28 Regard a dosage of 90 MME/d as maximal.28 While there is no analgesic ceiling, doses greater than 90 MME/d are associated with risk for overdose and should prompt referral to a pain specialist.31 Veterans Administration guidelines cite strong evidence that risk for overdose and death significantly increases at a range of 20 to 50 MME/d.33 Daily doses exceeding 90 MME/d should be documented with rational justification.28
Noncontrolled medications are preferred in the treatment of chronic pain. However, the utility of adjuvant options such as NSAIDs, duloxetine, or gabapentin were limited in Mr. G’s case due to his ESRD. Calcium channel α2-δ ligands may have been effective in reducing symptoms of neuropathic pain but would have had limited efficacy against osteoarthritis. Based on his low risk for opioid misuse, we decided to start Mr. G on oxycodone 2.5 mg PO, every 6 hours as needed for moderate-to-severe pain, and to follow up in 1 month. We also explained proper lifting form to him and encouraged him to continue with physical therapy.
Deciding to continue therapy with opioids
There is a lack of convincing evidence that opioid use beyond 6 months improves quality of life; patients do not report a significant reduction in pain beyond this time.28 Thus, a repeat evaluation of continued medical necessity is essential before deciding in favor of ongoing, long-term treatment with opioids. Continue prescribing opioids only if there is meaningful pain relief and improved function that outweighs the harms that may be expected for a given patient.31 With all patients, consider prescribing naloxone to accompany dispensed opioid prescriptions.28 This is particularly important for those at risk for misuse (history of overdose, history of substance use disorder, dosages ≥ 50 MME/d, or concurrent benzodiazepine use). Resources for prescribing naloxone in primary care settings can be found through Prescribe to Prevent at http://prescribetoprevent.org. Due to the established risk of overdose, avoid, if possible, concomitant prescriptions of benzodiazepines and opioids.31
Continue to: Follow-up and monitoring