Chronic Pain: How Challenging Are DDIs in the Analgesic Treatment of Inpatients with Multiple Chronic Conditions?

The Medication Quantification Scale 4.0: An Updated Index Based on Prescribers' Perceptions of the Risk Associated With Chronic Pain Medications

To quantify risks associated with drug utilization in the real world for the treatment of chronic pain (CP), an index called the Medication Quantification Scale (MQS) was developed in 1992 in the United States and last updated in 2003. This study aimed to update, adapt to the contemporary Canadian context, and validate a revised version of the MQS (the MQS-4.0). Step 1: An expert committee adapted the MQS to the Canadian clinical practice context. Step 2: An update of risk weights given to medication subclasses was achieved using a prescriber survey (weights were derived from median 0-10 scores given to each subclass). Step 3: Construct validity of the MQS-4.0 was assessed after applying risk weights to the medication use profile of persons living with CP covered by public drug insurance plan. Thirty-six medication subclasses were included in the MQS-4.0. A total of 207 prescribers (physicians, pharmacists, and nurse practitioners) participated in the perception survey; 10.63% identified as pain specialists. When risk weights were applied to prescription claims (n = 9,122), the MQS-4.0 score was associated (P < .05) with the MQS-III score and variables associated with polypharmacy (eg, Charlson Comorbidity Index, number of prescribers or health care visits). This study provides an updated index intended for adult populations based on prescribers' perceptions of the risk associated with CP medications that can be useful for clinical practice and research among persons living with CP in Canada. It will, however, be relevant to verify whether similar risk weights are obtained in future pain specialist surveys. PERSPECTIVE: The MQS-4.0 is an update of the MQS used for quantifying the risk associated with the use of analgesics/coanalgesics. Adequate psychometrics properties were found.

Polypharmacy and Excessive Polypharmacy Among Persons Living with Chronic Pain: A Cross-Sectional Study on the Prevalence and Associated Factors

Purpose

Polypharmacy can be defined as the concomitant use of ≥5 medications and excessive polypharmacy, as the use of ≥10 medications. Objectives were to (1) assess the prevalence of polypharmacy and excessive polypharmacy among persons living with chronic pain, and (2) identify sociodemographic and clinical factors associated with excessive polypharmacy.

Patients and Methods

This cross-sectional study used data from 1342 persons from the ChrOnic Pain trEatment (COPE) Cohort (Quebec, Canada). The self-reported number of medications currently used by participants (regardless of whether they were prescribed or taken over-the-counter, or were used for treating pain or other health issues) was categorized to assess polypharmacy and excessive polypharmacy.

Results

Participants reported using an average of 6 medications (median: 5). The prevalence of polypharmacy was 71.4% (95% CI: 69.0-73.8) and excessive polypharmacy was 25.9% (95% CI: 23.6-28.3). No significant differences were found across gender identity groups. Multivariable logistic regression revealed that factors associated with greater chances of reporting excessive polypharmacy (vs <10 medications) included being born in Canada, using prescribed pain medications, and reporting greater pain intensity (0-10) or pain relief from currently used pain treatments (0-100%). Factors associated with lower chances of excessive polypharmacy were using physical and psychological pain treatments, reporting better general health/physical functioning, considering pain to be terrible/feeling like it will never get better, and being employed.

Conclusion

Polypharmacy is the rule rather than the exception among persons living with chronic pain. Close monitoring and evaluation of the different medications used are important for all persons, especially those with limited access to care.

[Optimizing the diagnosis and treatment of dorsalgia in real-world clinical practice: the secondary endpoint of the DORISS multicenter observational study]

OBJECTIVE

To evaluate the efficacy of Ipigrix in the complex treatment of patients with dorsalgia (DA) of the lumbosacral spine based on the results of the DORISS observational non-interventional multicenter study.

MATERIAL AND METHODS

Overall 3563 patients with verified diagnoses of DA at 200 clinical centers within the Russian Federation who received comparable baseline therapy according to nosological standards were examined, some of them additionally received oral or staggered treatment with Ipigrix. Baseline therapy for DA was given to 376 patients (treatment group 1), combination of baseline with oral Ipigrix was given to 1026 patients (group 2), and combination with staggered prescription of ipidacrine - to 2161 (group 3). Secondary endpoint of the study included analysis of the improvement of clinical symptoms, values of pain NRS and DN4 scales together with Roland-Morris questionnaire during the period of observation depending on the therapy with an assessment of its safety.

RESULTS

The results of the analysis of covariance allowed to exclude the influence of confounders (age and initial indicators of the utilized scales) on DA outcomes and demonstrated the greatest pain reduction in patients who additionally received Ipigrix via the staggered scheme. The inter-group comparison aligned by pseudorandomization showed statistically significant benefits of combined therapy regardless of the type of Ipigrix administration concerning main vertebral syndrome manifestations, sensory and motor disturbances, relief of pain, as well as neuropathic symptoms, improvement of neurophysiological parameters and restoration of life functioning without serious drug related adverse events.

CONCLUSION

Ipigrix (ipidacrine) can be considered an effective and safe adjuvant analgesic in the treatment of DA.

Association between Opioids Prescribed to Medical Inpatients with Pain and Long-Term Opioid Use

OBJECTIVES

Opioid receipt during medical hospitalizations may be associated with subsequent long-term use. Studies, however, have not accounted for pain, which may explain chronic use. The objective of this study was to identify the association between opioid exposure during a medical hospitalization and use 6 to 12 months later.

METHODS

This was an observational cohort study using electronic health record data from 10 hospitals in the Cleveland Clinic Health System in 2016. Eligible patients were opioid-naïve adults with pain age 18 years and older, admitted to a medical service. Outcomes were opioid receipt during hospitalization and on discharge, and long-term opioid use, defined as ≥2 prescriptions for at least 30 pills 6 to 12 months posthospitalization. We estimated the odds of long-term opioid use by opioid exposure during the hospitalization. Models controlled for patient demographic and clinical characteristics, including patient-reported pain.

RESULTS

Among the 2971 patients in the sample, 64% received opioids during their hospitalization and 28% were discharged with opioids. Overall, 3% of patients had long-term use. Higher pain score was associated with greater odds of long-term use (adjusted odds ratio [aOR] per point increase 1.11; 95% confidence interval [CI] 1.03-1.19). No patient factors were associated with long-term use. Receipt of an opioid during a hospitalization only was not associated with long-term use (aOR 1.44, 95% CI 0.81-2.57), but receipt at discharge was (aOR 1.96, 95% CI 1.08-3.56).

CONCLUSIONS

Although opioid receipt at discharge was associated with long-term use, the number of patients this applied to was small. Pain severity was an important predictor of long-term use and should be accounted for in future studies.

The Distinct Functions of Dopaminergic Receptors on Pain Modulation: A Narrative Review

Chronic pain is considered an economic burden on society as it often results in disability, job loss, and early retirement. Opioids are the most common analgesics prescribed for the management of moderate to severe pain. However, chronic exposure to these drugs can result in opioid tolerance and opioid-induced hyperalgesia. On pain modulation strategies, exploiting the multitarget drugs with the ability of the superadditive or synergistic interactions attracts more attention. In the present report, we have reviewed the analgesic effects of different dopamine receptors, particularly D1 and D2 receptors, in different regions of the central nervous system, including the spinal cord, striatum, nucleus accumbens (NAc), and periaqueductal gray (PAG). According to the evidence, these regions are not only involved in pain modulation but also express a high density of DA receptors. The findings can be categorized as follows: (1) D2-like receptors may exert a higher analgesic potency, but D1-like receptors act in different manners across several mechanisms in the mentioned regions; (2) in the spinal cord and striatum, antinociception of DA is mainly mediated by D2-like receptors, while in the NAc and PAG, both D1- and D2-like receptors are involved as analgesic targets; and (3) D2-like receptor agonists can act as adjuvants of μ-opioid receptor agonists to potentiate analgesic effects and provide a better approach to pain relief.

Characterizing tramadol users with potentially inappropriate co-medications: A latent class analysis among older adults

Background

Although tramadol is an effective weak opioid analgesic, careful monitoring of potential central nervous system adverse reactions in older adults is needed, especially when used with concomitant medications which may trigger the adverse effects. We aimed to characterize tramadol users with potentially inappropriate co-medications in older adults using a latent class analysis (LCA).

Method

Patients aged 65 years or older using tramadol and receiving potentially inappropriate co-medications were included from a nationwide healthcare claims database. We defined antidepressants, first-generation antihistamines, and anxiolytics as potentially inappropriate co-medications. We applied an LCA for grouping tramadol users based on the common characteristics of medication use and healthcare utilization, and each patient was probabilistically assigned to a class. Patients’ characteristics in different latent classes were compared. Potential adverse drug reactions (ADRs) was defined as the any visits for emergency department after the occurrence of potentially inappropriate co-medications. Logistic regression analysis was used to examine the association between latent classes and potential ADRs.

Results

We identified four distinct latent classes of tramadol users representing different patterns of co-medications: multiple potential drug-drug interaction (pDDI) combination users, antihistamines-tramadol users, antidepressants-tramadol users, and anxiolytics-tramadol users. Multiple pDDI combination users showed high proportion of regular tramadol use, tended to visit more medical institutions, and had a high Charlson comorbidity score. The duration of use of potentially inappropriate co-medications with tramadol was the longest in multiple pDDI combination users and the shortest in antihistamines-tramadol users.

When compared with antihistamines-tramadol users, increased potential ADR risk was observed in multiple pDDI combination users (adjusted odds ratio (OR), 1.81; 95% confidence interval (CI), 1.75–1.88), antidepressants-tramadol users (1.24; 1.19–1.29), and anxiolytics-tramadol users (1.04; 1.00–1.08).

Conclusions

Four distinct classes were identified among older adults using tramadol and potentially inappropriate co-medications. Differences in potential ADR risk were observed between these classes. These findings may help to identify patients at a high risk for ADRs owing to potentially inappropriate co-medications with tramadol.

Use of pain relieving drugs in community-dwelling older people with and without type 2 diabetes

AIMS

To analyze the use of pain medication among community-dwelling people aged 65 years or older with and without type 2 diabetes in primary care.

METHODS

A total of 187 patients with and 176 patients without diabetes were randomly selected from a primary care sample of 389 patients with diabetes and 604 age- and gender-matched controls. Pain status was defined as no pain, nociceptive pain or neuropathic pain. Pain medication (paracetamol, NSAID, opioids, neuropathic pain medication) use was based on electronic patient records and checked by a physician during a health examination.

RESULTS

Some pain was present in 90 (51%) patients without and in 106 (57%) patients with diabetes (p = 0.55). Of the patients without diabetes, 109 (62%) and with diabetes 123 (66%) used some pain medication (p = 0.45). The respective proportions for the regular use were 13% and 11% and for the as needed use 56% and 61%. Diabetes was not associated with any of the pain medications used. The use of pain-relieving drugs was most common for neuropathic pain.

CONCLUSIONS

The present study indicated that community-dwelling people with and without diabetes used pain medication similarly. Pain medication was used mostly as needed instead of being regular.

A Review of Scientific Evidence for THC:CBD Oromucosal Spray (Nabiximols) in the Management of Chronic Pain

The 20% prevalence of chronic pain in the general population is a major health concern given the often profound associated impairment of daily activities, employment status, and health-related quality of life in sufferers. Resource utilization associated with chronic pain represents an enormous burden for healthcare systems. Although analgesia based on the World Health Organization’s pain ladder continues to be the mainstay of chronic pain management, aside from chronic cancer pain or end-of-life care, prolonged use of non-steroidal anti-inflammatory drugs or opioids to manage chronic pain is rarely sustainable. As the endocannabinoid system is known to control pain at peripheral, spinal, and supraspinal levels, interest in medical use of cannabis is growing. A proprietary blend of cannabis plant extracts containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) as the principal cannabinoids is formulated as an oromucosal spray (USAN name: nabiximols) and standardized to ensure quality, consistency and stability. This review examines evidence for THC:CBD oromucosal spray (nabiximols) in the management of chronic pain conditions. Cumulative evidence from clinical trials and an exploratory analysis of the German Pain e-Registry suggests that add-on THC:CBD oromucosal spray (nabiximols) may have a role in managing chronic neuropathic pain, although further precise clinical trials are required to draw definitive conclusions.

[Multimorbidity management and the physician's daily clinical dilemma]

About 20-25% of all persons and about 90% of all patients who are acutely hospitalized in internal medicine departments have multiple acute or chronic diseases. They are multimorbid. The encounter with multimorbid patients has become the most common situation in the health care system. Theoretically, multimorbidity results in an innumerable potential disease constellations. In addition, the likelihood of interactions between diseases (disease-disease interactions, DDI) and the complexity increases overproportionately with each additional disease. However, multimorbidity often occurs in typical diadic, triadic, or higher characteristic combinations, in "disease clusters", e. g., vascular risk factors, heart and lung diseases, Frailty and dementia, psychiatric and somatic disorders. Such combinations lead to a worsening of the overall prognosis. In addition, DDIs are often difficult to treat or are life-threatening. Examples of DDIs include the following: anticoagulation and simultaneous severe bleeding, pain treatment and hypertension or renal insufficiency, depression and reduced medication adherence, chronic obstructive pulmonary disease and depression, Frailty and neurodepressant drugs and frequent falls, and combined psychiatric and somatic disorders. Such DDIs are common. Nevertheless, there are few studies and clinical guidelines that address these issues. The care of multimorbid patients is, therefore, heavily reliant upon guidelines developed mostly for single diseases. However, multimorbidity and serious DDIs are usually not addressed in these. Clinical guidelines can thus inadvertently jeopardize the safety of persons suffering from multiple diseases. In addition, stressful dilemmas arise for physicians encountering DDIs because of difficult treatment decisions.

Drug-drug interactions involving antidepressants: focus on desvenlafaxine

Psychiatric and physical conditions often coexist, and there is robust evidence that associates the frequency of depression with single and multiple physical conditions. More than half of patients with depression may have at least one chronic physical condition. Therefore, antidepressants are often used in cotherapy with other medications for the management of both psychiatric and chronic physical illnesses. The risk of drug-drug interactions (DDIs) is augmented by complex polypharmacy regimens and extended periods of treatment required, of which possible outcomes range from tolerability issues to lack of efficacy and serious adverse events. Optimal patient outcomes may be achieved through drug selection with minimal potential for DDIs. Desvenlafaxine is a serotonin-norepinephrine reuptake inhibitor approved for the treatment of adults with major depressive disorder. Pharmacokinetic studies of desvenlafaxine have shown a simple metabolic profile unique among antidepressants. This review examines the DDI profiles of antidepressants, particularly desvenlafaxine, in relation to drugs of different therapeutic areas. The summary and comparison of information available is meant to help clinicians in making informed decisions when using desvenlafaxine in patients with depression and comorbid chronic conditions.

Opioid-induced inhibition of the human 5-HT and noradrenaline transporters in vitro: link to clinical reports of serotonin syndrome

Background and Purpose

Opioids may inhibit the 5‐HT transporter (SERT) and the noradrenaline transporter (NET). NET inhibition may contribute to analgesia, and SERT inhibition or interactions with 5‐HT receptors may cause serotonergic toxicity. However, the effects of different opioids on the human SERT, NET and 5‐HT receptors have not been sufficiently studied.

Experimental Approach

We determined the potencies of different opioids to inhibit the SERT and NET in vitro using human transporter‐transfected HEK293 cells. We also tested binding affinities at 5‐HT_1A, 5‐HT_2A and 5‐HT_2C receptors. Additionally, we assessed clinical cases of the serotonin syndrome associated with each opioid reported by PubMed and a World Health Organization database.

Key Results

Dextromethorphan, l(R)‐methadone, racemic methadone, pethidine, tramadol and tapentadol inhibited the SERT at or close to observed drug plasma or estimated brain concentrations in patients. Tapentadol was the most potent NET inhibitor. Pethidine, tramadol, l(R)‐methadone, racemic methadone, dextromethorphan and O‐desmethyltramadol also inhibited the NET. 6‐Monoacetylmorphine, buprenorphine, codeine, dihydrocodeine, heroin, hydrocodone, hydromorphone, morphine, oxycodone and oxymorphone did not inhibit the SERT or NET. Fentanyl interacted with 5‐HT_1A receptors and methadone, pethidine and fentanyl with 5‐HT_2A receptors, in the low micromolar range. Opioids most frequently associated with the serotonin syndrome are tramadol, fentanyl, tapentadol, oxycodone, methadone and dextromethorphan.

Conclusions and Implications

Some synthetic opioids interact with the SERT and NET at potentially clinically relevant concentrations. SERT inhibition by tramadol, tapentadol, methadone, dextromethorphan and pethidine may contribute to the serotonin syndrome. Direct effects on 5‐HT_1A and/or 5‐HT_2A receptors could be involved with methadone and pethidine.