Chronic opioid use is a risk factor for the development of central sleep apnea and ataxic breathing.

BACKGROUND: Chronic opioid therapy for pain management has increased dramatically without adequate study of potential deleterious effects on breathing during sleep. METHODS: A retrospective cohort study comparing 60 patients taking chronic opioids matched for age, sex, and body mass index with 60 patients not taking opioids was conducted to determine the effect of morphine dose equivalent on breathing patterns during sleep. RESULTS: The apnea-hypopnea index was greater in the opioid group (43.5/h vs 30.2/h, p < .05) due to increased central apneas (12.8/h vs 2.1/h; p < .001). Arterial oxygen saturation (SpO2) in the opioid group was significantly lower during both wakefulness (difference 2.1%, p < .001) and non-rapid eye movement (NREM) sleep (difference 2.2%, p < .001) but not during rapid eye movement (REM) sleep (difference 1.2%) than in the nonopioid group. Within the opioid group, and after controlling for body mass index, age, and sex, there was a dose-response relationship between morphine dose equivalent and apnea-hypopnea (p < .001), obstructive apnea (p < .001), hypopnea (p < .001), and central apnea indexes (p < .001). Body mass index was inversely related to apnea-hypopnea index severity in the opioid group. Ataxic or irregular breathing during NREM sleep was also more prevalent in patients who chronically used opioids (70% vs 5.0%, p < .001) and more frequent (92%) at a morphine dose equivalent of 200 mg or higher (odds ratio = 15.4, p = .017). CONCLUSIONS: There is a dose-dependent relationship between chronic opioid use and the development of a peculiar pattern of respiration consisting of central sleep apneas and ataxic breathing. Although potentially significant, the clinical relevance of these observations remains to be established.

Etoricoxib provides analgesic efficacy to patients after knee or hip replacement surgery: a randomized, double-blind, placebo-controlled study.

UNLABELLED: In this randomized, double-blind, placebo-controlled, multicenter study we assessed the analgesic effect of etoricoxib (a new cyclooxygenase-2 inhibitor) in patients having had knee or hip replacement surgery. A total of 228 patients with moderate or severe pain were randomly allocated within 72 h after surgery to receive etoricoxib 120 mg, controlled-release naproxen sodium 1100 mg, or placebo (1:1:1) on day 1 followed by etoricoxib and placebo (1:2) on days 2 to 7. Patients reported pain scores, rescue (opioid-combination) medication use, and the response to study drug. On day 1, etoricoxib provided an analgesic effect superior to placebo and similar to controlled-release naproxen sodium as demonstrated by the total pain relief score over 8 h, the primary end-point; least-squares mean scores were 11.0, 11.5, and 5.6, respectively (P < 0.001 versus placebo). Similarly, a larger percentage of patients receiving etoricoxib and naproxen sodium than those receiving placebo reported good to excellent responses to study drug: 53%, 60%, and 26% respectively. On days 2-7, etoricoxib demonstrated a significant reduction of rescue medication use, 35% (P < 0.001 versus placebo). The clinical relevance of the decrease was confirmed by Patient's Global Evaluation (P < 0.05 versus placebo). Patients receiving etoricoxib also experienced significantly less "worst" and "average" pain than did those on placebo. Etoricoxib was generally well tolerated in this study; the incidence of adverse experiences was infrequent and similar across treatment groups. In summary, etoricoxib provided analgesia that was similar to controlled-release naproxen sodium on day 1 and superior to placebo with reduced supplemental opioid use over 7 days. IMPLICATIONS: In a postsurgery setting (knee and hip replacements), etoricoxib 120 mg provided analgesia superior to placebo and similar to controlled-release naproxen sodium 1100 mg. Patients receiving etoricoxib suffered less pain and took less opioid rescue medication compared with patients on placebo.