Efficacy and Safety Assessment of a Novel Once-Daily Tablet Formulation of Tramadol : A Randomised, Controlled Study versus Twice-Daily Tramadol in Patients with Osteoarthritis of the Knee

A Model-Based Meta-analysis to Compare Efficacy and Tolerability of Tramadol and Tapentadol for the Treatment of Chronic Non-Malignant Pain

Introduction

Pain is a major symptom in many medical conditions which can be relieved thanks to analgesics. The goal of this work was to present an indirect comparison of efficacy and tolerability profiles of two analgesics, tramadol and tapentadol, in patients with chronic non-malignant pain.

Methods

In the absence of a head-to-head comparison between these two opioid drugs, model-based meta-analyses were used to characterize the pain intensity time dynamics and evaluate the proportions of most frequent adverse events (constipation, nausea, vomiting, dizziness, and somnolence) and drop-outs (due to adverse event, as well as due to lack of efficacy) in each treatment group. Using these models, the investigational treatments were compared on the basis of Monte Carlo simulation outcomes.

Results

Data were extracted from 45 Phase II and Phase III studies representing a total of 81 treatment arms, i.e., approximately 13,000 patients. The pain intensity model shows, that after having adjusted for differences in baseline pain intensity and placebo effects, tramadol 300 mg once daily (qd) was slightly more effective in reducing pain than tapentadol 100–250 mg twice daily (bid), with a 46% change from baseline for the former versus 36% for the latter. From a tolerability standpoint, both drugs showed, as expected, increased risks of adverse events compared to placebo. Yet, tapentadol was associated with slightly lower risks of constipation, and nausea than tramadol.

Conclusion

Overall, the analysis showed that the benefit–risk profiles of tramadol 300 mg qd and tapentadol 100–250 mg bid were approximately even. The amount of data to characterize dose–response relationships was sufficient only in the tramadol group; public access to tapentadol efficacy and tolerability readouts across a wide dose range in chronic non-malignant pain would allow a comparison of therapeutic indices, a straight quantitation of the benefit–risk ratio. Knowing that their side-effects have been identified as potential hindrance to prescription, a broad and open access to clinical trial data in this indication is encouraged in order to facilitate the evaluation of the opiate analgesics clinical utility.

Electronic supplementary material

The online version of this article (doi:10.1007/s40122-014-0023-5) contains supplementary material, which is available to authorized users.

Tramadol Extended-Release for the Management of Pain due to Osteoarthritis

Current knowledge on pathogenesis of osteoarticular pain, as well as the consequent several, especially on the gastrointestinal, renal, and cardiovascular systems, side effects of NSAIDs, makes it difficult to perform an optimal management of this mixed typology of pain. This is especially observable in elderly patients, the most frequently affected by osteoarthritis (OA). Tramadol is an analgesic drug, the action of which has a twofold action. It has a weak affinity to mu opioid receptors and, at the same time, can result in inhibition of the reuptake of noradrenaline and serotonin in nociceptorial descending inhibitory control system. These two mechanisms, "opioidergic" and "nonopioidergic," are the grounds for contrasting certain types of pain that are generally less responsive to opioids, such as neuropathic pain or mixed OA pain. The extended-release formulation of tramadol has good efficacy and tolerability and acts through a dosing schedule that allows a high level of patients compliance to therapies with a good recovery outcome for the patients' functional status.

Extended-release formulations of tramadol in the treatment of chronic pain

INTRODUCTION

Tramadol is a centrally acting analgesic available throughout the world. Its dual opioid and non-opioid mechanisms of action, favorable efficacy and safety clinical profiles and non-controlled regulatory status in most markets contribute to its widespread use. A drawback of the immediate-release formulation of tramadol (four-times-a-day dosing) might be addressed by an extended-release formulation. Extended-release formulations also can offer advantages in the management of chronic pain: convenience, reduced pill burden (possibly leading to improved compliance) and the attenuation of peaks and troughs in serum concentration (possibly leading to reduced adverse effects).

AREAS COVERED

The authors review tramadol's mechanisms of action and the clinical literature regarding the use of tramadol extended-release formulations for the management of conditions involving chronic pain, such as neuropathic pain syndromes, osteoarthritis and cancer pain.

EXPERT OPINION

Based on the literature cited, extended-release formulations of tramadol seem to offer a rational and important addition to the analgesic armamentarium. As is true for all such options, the benefits and risks must be assessed for each patient.

Outcomes associated with opioid use in the treatment of chronic noncancer pain in older adults: a systematic review and meta-analysis

This systematic review summarizes existing evidence regarding the efficacy, safety, and abuse and misuse potential of opioids as treatment for chronic noncancer pain in older adults. Multiple databases were searched to identify relevant studies published in English (1/1/80-7/1/09) with a mean study population age of 60 and older. Forty-three articles were identified and retained for review (40 reported safety and efficacy data, the remaining 3 reported misuse or abuse outcome data). The weighted mean subject age was 64.1 (mean age range 60-73). Studies enrolled patients with osteoarthritis (70%), neuropathic pain (13%), and other pain-producing disorders (17%). The mean duration of treatment studies was 4 weeks (range 1.5-156 weeks), and only five (12%) lasted longer than 12 weeks. In meta-analyses, effect sizes were -0.557 (P<.001) for pain reduction, -0.432 (P<.001) for physical disability reduction, and 0.859 (P=.31) for improved sleep. The effect size for the Medical Outcomes Study 36-item Health Survey was 0.191 (P=.17) for the physical component score and -0.220 (P=.04) for the mental component score. Adults aged 65 and older were as likely as those younger than 65 to benefit from treatment. Common adverse events included constipation (median frequency of occurrence 30%), nausea (28%), and dizziness (22%) and prompted opioid discontinuation in 25% of cases. Abuse and misuse behaviors were negatively associated with older age. In older adults with chronic pain and no significant comorbidity, short-term use of opioids is associated with reduction in pain intensity and better physical functioning but poorer mental health functioning. The long-term safety, efficacy, and abuse potential of this treatment practice in diverse populations of older persons remain to be determined.

Adverse event profile of tramadol in recent clinical studies of chronic osteoarthritis pain

OBJECTIVE

To review the safety profile of tramadol hydrochloride (tramadol) in the treatment of chronic osteoarthritis pain, with specific reference to the incidence of adverse events (AEs) reported in large clinical trials.

METHODS

An extensive review of published clinical trials with tramadol was conducted, using literature searches in MEDLINE and EMBASE (since 1997) and the key search terms: tramadol, immediate-release (IR), extended-release (ER), sustained-release (SR), chronic pain, and osteoarthritis. Studies were included based on appropriate study design, appropriately reported safety data, and chronic osteoarthritis as a pain condition. Secondary analyses of previously published pain studies were excluded.

RESULTS

Fifteen studies met the inclusion criteria. The most common AEs reported across all tramadol formulations were nausea, dizziness, constipation, vomiting, somnolence, and headache. Most AEs were mild to moderate in severity and occurred more commonly during initial treatment than during maintenance treatment. Differences in the rates of selected gastrointestinal and central nervous system AEs were seen between long-acting and immediate-release tramadol formulations, both within individual studies and across all studies. AEs appeared to be dose-dependent in fixed-dose studies.

CONCLUSIONS

This review provides a robust base for descriptive assessment of AEs associated with long-acting tramadol formulations. Although the actions of different tramadol formulations are biologically similar, differences in pharmacokinetics, drug-release patterns, and availability may influence the incidence of AEs associated with tramadol. Because of the limitations of a qualitative safety analysis across studies with different populations and study designs, any observed differences should be interpreted with caution, but these differences may help educate healthcare providers about tramadol treatment in patients with chronic osteoarthritis pain and help them select the optimal dose for specific patients.

Impact of opioid rescue medication for breakthrough pain on the efficacy and tolerability of long-acting opioids in patients with chronic non-malignant pain

Background

There is little evidence that short-acting opioids as rescue medication for breakthrough pain is an optimal long-term treatment strategy in chronic non-malignant pain. We compared clinical studies of long-acting opioids that allowed short-acting opioid rescue medication with those that did not, to determine the impact of opioid rescue medication use on the analgesic efficacy and tolerability of chronic opioid therapy in patients with chronic non-malignant pain.

Methods

We searched MEDLINE (1950 to July 2006) and EMBASE (1974 to July 2006) using terms for chronic non-malignant pain and long-acting opioids. Independent review of the search results identified 48 studies that met the study selection criteria. The effect of opioid rescue medication on analgesic efficacy and the incidence of common opioid-related side-effects were analysed using meta-regression.

Results

After adjusting for potentially confounding variables (study design and type of opioid), the difference in analgesic efficacy between the ‘rescue’ and the ‘no rescue’ studies was not significant, with regression coefficients close to 0 and 95% confidence intervals that excluded an effect of more than 18 points on a 0–100 scale in each case. There was also no significant difference between the ‘rescue’ and the ‘no rescue’ studies for the incidence of nausea, constipation, or somnolence in both the unadjusted and the adjusted analyses.

Conclusions

We found no evidence that rescue medication with short-acting opioids for breakthrough pain affects analgesic efficacy of long-acting opioids or the incidence of common opioid-related side-effects among chronic non-malignant pain patients.

A comparison of the analgesic efficacy of Tramadol Contramid OAD versus placebo in patients with pain due to osteoarthritis

One thousand twenty-eight (1,028) patients with pain due to osteoarthritis (OA) of the knee were enrolled in this multicenter, randomized, double-blind, parallel study designed to assess the analgesic efficacy and safety of Tramadol Contramid OAD compared to placebo. An open-label phase was followed by a double-blind phase, in which a total of 646 patients were randomized to double-blind treatment with placebo or Tramadol Contramid OAD. Patients were titrated to their optimal dose (200mg or 300 mg), which was maintained for 12 weeks. An absolute mean reduction of 3.0+/-2.1 on a Pain Intensity Numerical Rating Scale (PI-NRS) was noted in the Tramadol Contramid OAD treatment group. The difference between active and placebo groups regarding this absolute mean reduction was statistically significant (P<0.001) throughout the study. The responder analysis demonstrated that a significantly greater percentage of patients in the active treatment arm achieved a reduction of >or=1 and >or=2 points on the PI-NRS score by the end of the study (P=0.035). A significantly greater percentage of respondents in the Tramadol Contramid OAD group indicated improvement on both the Patient and Physician Global Impressions of Change (P=0.0002). Both the 200mg and 300 mg doses contributed to the overall superiority of Tramadol Contramid OAD. The most frequent adverse events were consistent with the known side effects of tramadol and were generally mild to moderate in intensity. These results confirm that Tramadol Contramid OAD given once daily is an efficacious and safe treatment for pain due to OA.

Study of hydration of cross-linked high amylose starch by solid state 13C NMR spectroscopy

Starch is subjected to chemical treatments such as cross-linking or hydroxypropylation to meet the material requirements for food uses or controlled release in the pharmaceutical industries. In this work, two types of cross-linking formulations have been employed for the preparation of high amylose starch for use as an excipient for sustained drug release. The structural differences and chain dynamics of the modified starches in the dry and hydrated states have been compared by the use of variable contact time cross polarization-magic angle spinning solid state (13)C NMR spectroscopy.

Pharmacokinetics and dose proportionality of three Tramadol Contramid® OAD tablet strengths

A three-way crossover study in 27 human volunteers was conducted to characterize the pharmacokinetics and to assess the dose proportionality of 100 mg, 200 mg and 300 mg strengths of a novel once-a-day tramadol controlled-release tablet (Tramadol Contramid OAD) following single-dose administration. Serial blood samples were collected at predefined timepoints over a 48 h period and racemic tramadol and O-desmethyltramadol concentrations in plasma were determined using a validated LC-MS/MS method. Pharmacokinetic parameters were derived using noncompartmental methods. Following dose normalization and logarithmic transformation of concentration-dependent parameters, the results were compared using analysis of variance (ANOVA). The residual variability thereby obtained was used to construct 90% classical confidence intervals. The two one-sided tests procedure was used for all pairwise comparisons. Dose proportionality was concluded since the 90% CI for the ratio of geometric means was included in the acceptance range of 0.80-1.25 for all comparisons.

Tramadol for osteoarthritis

BACKGROUND

Tramadol is increasingly used for the treatment of osteoarthritis because, in contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol does not produce gastrointestinal bleeding or renal problems, and does not affect articular cartilage.

OBJECTIVES

We sought to determine the analgesic effectiveness, the effect on physical function, the duration of benefit and the safety of oral tramadol in people with osteoarthritis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS databases up to August 2005.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of tramadol or tramadol plus paracetamol on pain levels and/or physical function in people with osteoarthritis. No language restriction was applied.

DATA COLLECTION AND ANALYSIS

We analyzed separately placebo-controlled and active-controlled studies. We used fixed-effect models for the meta-analyses as the results across studies were similar.

MAIN RESULTS

We included eleven RCTs with a total of 1019 participants who received tramadol or tramadol/paracetamol and 920 participants who received placebo or active-control. The placebo-controlled studies indicated that participants who received tramadol had less pain (-8.5 units on a 0 to 100 scale; 95% confidence interval (CI) -12.0 to -5.0) than patients who received placebo. This represents a 12% relative decrease in pain intensity from baseline. Participants who received tramadol had a 37% increase (95% CI 1.2 to 1.5) in the likelihood of reporting moderate improvement (number needed to treat to benefit = 6; 95% CI 4 to 9). Participants who received tramadol had 2.27 times the risk of developing minor adverse events and 2.6 times the risk of developing major adverse events, compared to participants who received placebo. Of every eight people who receive tramadol or tramadol/paracetamol, one will stop taking the medication because of adverse events, number needed to treat to harm (NNTH)= 8 (95% CI 7 to 12) for major adverse events. No conclusion could be drawn on how tramadol or tramadol/paracetamol compared with available pharmacological treatments because of the limited number of studies that evaluated such therapies.

AUTHORS' CONCLUSIONS

Tramadol or tramadol/paracetamol decreases pain intensity, produces symptom relief and improves function, but these benefits are small. Adverse events, although reversible and not life threatening, often cause participants to stop taking the medication and could limit tramadol or tramadol plus paracetamol usefulness.