Gastrointestinal events after opioid treatment in nonmalignant pain: correlates of occurrence and impact on health-related quality of life.

BACKGROUND: Gastrointestinal (GI) adverse effects are common with oral opioid treatments; their impact on health-related quality of life (HRQoL) is poorly understood.

OBJECTIVES: To estimate the extent to which GI adverse effects impact HRQoL.

DESIGN: 28-day prospective, multicenter, observational registry.

SETTING: Outpatient settings.

PARTICIPANTS: Six hundred thirty-nine patients with acute pain (AP; n = 243) and acute episodes of chronic pain (CP; pain ≥3 months; n = 396) requiring treatment with a prescription medication containing oxycodone immediate-release on an as-needed basis for ≥5 days.

MEASUREMENTS: Modified Memorial Symptom Assessment Scale; 12-item Short Form Health Survey (SF-12) Physical (PCS); and Mental Component Scales (MCS) on days 3, 7, 14, 21, and 28. Repeated measures mixed models provided estimates of impact of GI events on HRQoL.

RESULTS: Forty-seven percent of AP patients and 24 percent of CP patients developed constipation. More AP patients than CP developed nausea (31 percent vs 19 percent). After adjustment for confounders, constipation was associated with a 3.9-point reduction in PCS and a 2.3-point reduction in MCS among AP patients (p < 0.0001). Among AP patients, nausea/vomiting was associated with a reduction in PCS (PCS = 3.2; p < 0.0001) and MCS (MCS = 2.2; p = 0.0042). Among CP patients, constipation was not associated with reductions in HRQoL, and nausea/vomiting was associated with a reduction in MCS but not PCS (MCS = 2.4; p ≤ 0.0001).

CONCLUSION: GI symptoms accompanying oral opioid treatment are common and negatively affect HRQoL differentially for those with AP and CP. Effective approaches for managing opioid-induced GI symptoms are warranted.