Long-term efficacy of OROS® hydromorphone combined with pregabalin for chronic non-cancer neuropathic pain.

BACKGROUND AND OBJECTIVES: Treatment for chronic non-cancer neuropathic pain can be complicated by side effects and drug interactions. Combining opioid analgesics and calcium channel modulators may overcome these and improve efficacy. The objective of the present study was to evaluate the efficacy and safety of OROS® hydromorphone combined with pregabalin in patients with chronic non-cancer neuropathic pain. METHODS: This retrospective observational study was conducted on clinical records from patients aged ≥18 years with chronic non-cancer neuropathic [>4 on the Douleur Neuropathique en 4 questions (DN4) scale] pain of ≥6 months duration, with severe intensity [>4 on the Numerical Rating Scale (NRS); range 0-10], who attended all visits and had ≥12 months of follow-up at the Tor Vergata University Polyclinic Hospital, from November 2008 to February 2011. Patients received an oral combination of OROS® hydromorphone and pregabalin. Pain was evaluated at each visit (months 1, 3, 6, 9, and 12) using the NRS and DN4 scale; Patients' Global Impression of Change (PGIC) was administered at months 1, 6, and 12. Dosage and side effects were recorded at each visit. RESULTS: Of 1,292 patients (32 % men, mean ± SD age 67.6 ± 11.9 years), 1,126 attended all visits. Seventeen percent (n = 224) had purely neuropathic pain. Initial mean dosage was 6.06 ± 2.00 mg/day for OROS® hydromorphone, 113.02 ± 21.94 mg/day for pregabalin. Dosages increased up to month 6, and returned to near initial dosages at month 12 (range 4-120 mg/day for OROS® hydromorphone; 75-600 mg/day for pregabalin). NRS pain scores (mean ± standard deviation) were 7.25 ± 1.34 at baseline and 1.85 ± 1.36 at 12 months (p < 0.0001); DN4 scores were 6.19 ± 1.65 at baseline, reduced to 1.84 ± 1.25 at 12 months (p < 0.0001), reductions of 74.4 and 70.2 %, respectively. More than 90 % of patients had a ≥50 % score reduction on both scales after 12 months. The PGIC scale showed that >75 % of patients felt improvement at 1 month, increasing to 91 % and 93 % at 6 and 12 months. The incidence of side effects was similar between elderly (aged >65 years) and younger subjects; there were no cases of addiction. CONCLUSIONS: The OROS® hydromorphone and pregabalin combination was efficacious for chronic non-cancer neuropathic pain and well tolerated, providing significant pain reduction without the risk of addiction and with a good tolerability profile, regardless of age.

Palmitoylethanolamide in the treatment of chronic pain caused by different etiopathogenesis.

OBJECTIVE: To assess the efficacy and safety of palmitoylethanolamide (PEA), an endogenous fatty acid amide belonging to the N-acylethanolamines family, in reducing pain severity in patients with pain associated to different pathological conditions. METHODS: This was an observational study conducted on 610 patients who were unable to effectively control chronic pain with standard therapies. PEA (600 mg) was administered twice daily for 3 weeks followed by single daily dosing for 4 weeks, in addition to standard analgesic therapies or as single therapy. The primary outcome measure was the mean score pain severity evaluated by the numeric rating scale. Safety was also evaluated. RESULTS: PEA treatment significantly decreased the mean score pain intensity evaluated in all patients who completed the study. The PEA effect was independent of the pain associated pathological condition. PEA-induced decrease of pain intensity was present also in patients without concomitant analgesic therapy. Importantly, PEA showed no adverse effects. CONCLUSIONS: In this study, PEA was effective and safe in the management of chronic pain in different pathological conditions.

Adherence and long-term effect of oxycodone/paracetamol in chronic noncancer pain: a retrospective study.

INTRODUCTION: Long-term administration of opiates in patients with chronic noncancer pain (CNCP) is subject to debate due to insufficient clinical evidence to support efficacy and tolerability. METHODS: This retrospective analysis used hospital records to investigate the effects of low doses of the combination of oxycodone/paracetamol on CNCP in an outpatient clinic setting to verify adherence to therapy and long-term efficacy. All patients receiving therapy for CNCP were examined between May and September 2010 and information was collected on medication, duration of therapy, and static and dynamic pain measured using numeric rating scales (NRS) from relevant charts. RESULTS: Two hundred and thirty-one patients (157 men, 68%) with a mean (± SD) age of 66.4±15.5 years were analyzed. Pain indexes at baseline revealed a mean (± SD) static NRS (sNRS) of 3.5±1.77 and a mean dynamic NRS (dNRS) of 7.24±1.33. At last follow-up, mean (± SD) pain reductions versus baseline were 1.58±1.42 for sNRS and 3.04±1.43 for dNRS (P<0.0001 for both). Regarding the duration of therapy, 54 patients (23.4%) were treated for <4 months, and 177 patients (76.6%) for 4 months up to 23 months. Pain reduction was significant in all groups (P<0.0001) but was greatest in patients who had been receiving therapy for ≥4 months. Improvements in pain relief were not associated with an increase in daily dose, which remained stable or decreased slightly over time. DISCUSSION: The results of this study support the hypothesis that an opiate-based combination at low doses improves tolerability and adherence and results in patients obtaining long-term efficacy. Larger studies of the use of opiates in this setting and clinical monitoring on the regional and national level may convince clinicians to view opiates as efficacious analgesics and not as dangerous substances of abuse.

Arterial blood pressure regulation following aorta clamping and declamping during surgery.

In this paper, we propose the use of black box models for the system identification of the cardiopulmonary baroreflex control of arterial resistance and of ventricular contractility and of arterial baroreflex control of heart rate (HR) from invasive, continuous measurements of arterial blood pressure (ABP) and central venous pressure (CVP), and non invasive, continuous recordings of ECG and respiration. Two crucial phases of the abdominal aortic aneurism (AAA) repair were investigated: the clamping and declamping of aorta. The objective of the present work is to evaluate and to test the ability to monitor baroreflex responses to clamping and declamping maneuvers preceding and following aneurism removal.

Estimation of baroreflex sensitivity during anesthesia induction with propofol.

This paper presents the analysis of the autonomic nervous system (ANS) control and cardiac baroreflex sensitivity in patients undergoing general anesthesia for major surgery, with the goal of evaluating the effects of anesthesia bolus induction with propofol on autonomic control of heart rate (HR) and arterial blood pressure (ABP). The increase in baroreflex gain in the LF band observed through two different methods hints at the fact that the baroreflex may increase heart period (HP) following a transient ABP decrease, but its response displays a larger amplitude, to compensate for the blunting of the sympathetic action on heart rate and vascular resistance.

Oxycodone/paracetamol: a low-dose synergic combination useful in different types of pain.

The combination of two analgesic agents offers several advantages in the treatment of chronic pain. Paracetamol (acetaminophen) has central analgesic activity without a nonsteroidal anti-inflammatory drug (NSAID)-like or opioid-like effect. Oxycodone is a semisynthetic opioid agonist. The oral fixed-dose combination of oxycodone and paracetamol immediate-release formulation has a synergistic mechanism of action that is useful for moderate-to-severe pain and for nonresponders to NSAIDs or paracetamol alone. This fixed-dose combination offers several advantages: lower individual drug doses can be used because of their synergistic mechanisms of action, its opioid-sparing effect and it has a good efficacy and tolerability profile. Efficacy and safety of this fixed-dose combination were assessed in a wide range of clinical settings: in patients with osteoarthritis or chronic musculoskeletal pain, including when complicated by a neuropathic component; for chronic pain in elderly patients; cancer-related pain; postoperative pain; and for neuropathic pain, in the latter case usually given in combination with an NSAID or other drugs. The large variety of indications for which this fixed-dose combination may be useful can be attributed to the pharmacological synergy between oxycodone and paracetamol and because lower individual drug dosages can be used, suggesting that this should be a first-line agent for the treatment of chronic moderate-to-severe pain.

Clinical and psychosocial correlates of acute pain in herpes zoster.

BACKGROUND: Acute and persistent pain are the most significant clinical manifestations of herpes zoster (HZ), but the characteristics of acute pain in HZ patients have been inadequately investigated. OBJECTIVES: To correlate the severity of acute pain with clinical, demographic and psychosocial characteristics of HZ patients. STUDY DESIGN: Five hundred thirty-three patients with acute HZ were recruited by 119 dermatologists who collected medical and demographic data at diagnosis, provided counselling and therapy where appropriate and asked the patients to complete the Short Italian Questionnaire designed for comprehensive evaluation of HZ patients. RESULTS: In a univariate analysis, greater acute pain severity was significantly associated with female gender, number of dermatomes affected, presence of prodromal pain, abnormal sensations (dysesthesia), education level, anxiety and depression. Quality of life, even if greatly reduced, did not correlate with the intensity of pain. In a multivariate model, the intensity of pain was independently associated with the extent of rash (p=0.042), presence of prodromal pain (p=0.005), dysesthesia, education level (p=0.040), and depression (p<0.001), but not with gender, anxiety or quality of life. CONCLUSIONS: This study suggests that in patients with acute HZ the severity of the disease and depression at presentation are the main correlates of pain intensity.