Use of non-opioid analgesics as adjuvants to opioid analgesia for cancer pain management in an inpatient palliative unit: does this improve pain control and reduce opioid requirements?

Abstract

Background Cancer pain is complex, and despite the introduction of the WHO cancer pain ladder, few studies have looked at the prevalence of adjuvant medication use in an inpatient palliative medicine unit. In this study, we evaluate the use of adjuvant pain medications in patients admitted to an inpatient palliative care unit and whether their use affects pain scores or opiate dosing. Methods In this retrospective observational study, patients admitted to the inpatient palliative care unit over a 3-month period with a diagnosis of cancer on opioid therapy were selected. Data pertaining to demographics, diagnosis, oral morphine dose equivalent of the opioid at the time of discharge, adjuvant analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), and pain scores as reported by nurses and physicians were collected. Results Seventy-seven patients were eligible over a 3-month period, out of which 65 (84 %) were taking an adjuvant medication. The most commonly prescribed adjuvant was gabapentin (70 %). Fifty-seven percent were taking more than one adjuvant. There were more women in the group receiving adjuvants (57 vs. 17%, p=0.010). Those without adjuvants compared with those on adjuvants did not have worse pain scores on discharge as reported by physicians (0.8±0.8 vs. 1.0±0.7, p=0.58) or nurses (2.0±2.7 vs. 2.1±2.6, p=0.86). There was no difference in morphine equivalent doses of the opioid in both groups (median (min, max); 112 (58, 504) vs. 200 (30, 5,040)) at the time of discharge; 75-80 % of patients had improvement in pain scores as measured by a two-point reduction in numerical rating scale (NRS). Discussion This study shows that adjuvant medications are commonly used for treating pain in patients with cancer. More than half of study population were on two adjuvants or an adjuvant plus NSAID along with an opioid. We did not demonstrate any benefit in terms of improved pain scores or opioid doses with adjuvants, but this could reflect confounding variables and physician choice. Larger prospective studies are needed to define the opioid-sparing effects of adjuvants. Conclusion Adjuvant agents are used in over 80 % of those treated for cancer pain.

The research on long-term clinical effects and patients’ satisfaction of gabapentin combined with oxycontin in treatment of severe cancer pain

“…The analgesic adjuvant medications were prescribed in every ladder of WHO 3-step analgesic therapy, showing that adjuvant was important for treatment of cancer pain. [19] Shinde et al [5] found that more than 80% patients were on the 2 or more than 2 adjuvant medications along with opioid in their retrospective observational study, which reviewed the efficacy of cancer pain regimen for the patients during staying in palliative cancer treatment center. But their results showed that there were not any benefits in terms of improved pain scores or opioid doses with adjuvants, but this could reflect confounding variables as a wide variety of diseases with varying severity, physician choices of combined regimen with inconsistent length of observation.…”

“…Adjuvant drugs can treat specific type of pain, improve the symptom of the accidental pain, increase the analgesic effect, and sometimes reduce side effects to some extent. Shinde et al [5] demonstrated that adjuvant drugs were used in 80% of cancer pain treatment in their retrospective study. Gabapentin, a new generation of anticonvulsant drug, was found to reduce metastatic bone cancer pain [6] and improve visceral pain.…”

Sex differences in innate immunity and its impact on opioid pharmacology

“…Although it is not known whether the response to NSAIDs is sexually dimorphic, robust sex differences have been observed in studies examining the prevalence of NSAID use (Dominick et al, 2003;Fosbol et al, 2008). Indeed, disparate incidence rates of 57% female vs. 17% male for NSAID prescriptions for cancer pain have been reported (Shinde et al, 2015). NSAIDs inhibit the enzyme cyclooxygenase (COX), which is responsible for production of inflammatory prostanoids.…”

Patterns and predictors of outpatient opioid use after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

“…However, it is currently unclear whether the perioperative opioid-sparing effects of these non-opioid analgesic adjuncts reduce the risk of prolonged opioid use [27]. Furthermore, outside the perioperative setting, some studies have not demonstrated opioid-sparing effects associated with non-opioid analgesic use [28,29]. For example, in a retrospective study of 78 cancer patients admitted to a palliative care unit, the administration of non-opioid analgesic adjuncts was not associated with reduced opioid consumption or improved pain scores [28].…”