Pharmacotherapy of Osteoarthritis

Evaluation of vitamin C protective effect on the cerebrocortical antioxidant defense, histopathological, pro-apoptotic p53 and anti-apoptotic Bcl2 expressions against tramadol neurotoxicity in rats

BACKGROUND

Reported tramadol toxicity emphasizes the necessity to recognize its mechanism of toxicity, particularly to the brain tissue.

AIM

This study aimed to evaluate the protective effect of vitamin C (Vit C) in cerebrocortical toxicity mediated by tramadol in rats using biochemical and histological parameters.

MATERIAL AND METHODS

Forty-eight albino rats were randomly divided into eight groups, (n = 6/group) as follow: the control group received normal saline and vitamin C group received vitamin C (200 mg/kg per oral). Tramadol 50, 100, 150 groups received tramadol in doses of (50, 100 and 150 mg/kg per oral, respectively); Tramadol 50+ Vit C, 100+ Vit C, 150+ Vit C groups received vitamin C (200 mg/kg per oral) plus tramadol in doses of (50, 100 and 150 mg/kg per oral, respectively). Rats had received vitamin C and tramadol daily for 30 days. Blood and brain tissues samples were harvested for biochemical, histopathological, immunohistochemical and electron microscopic examinations.

RESULTS

Tramadol administration leads to a significant elevation of MDA, NO levels and a significant decrease in antioxidants parameters (CAT, SOD and GSH) in the tissues of cerebral cortices in rats which were directly proportional to the dose of tramadol. In histological investigations, tramadol-treated groups showed pyknotic pyramidal cells, multiple red neurons and shrinking red neurons with hallows around it and apoptotic cells were detected. These biochemical abnormalities and histological impairment were ameliorated in groups with tramadol low doses by the co-treatment with vitamin C.

CONCLUSION

vitamin C has antioxidant and anti-apoptotic potentials against tramadol neurotoxicity via suppression of oxidative stress, lipid peroxidation, structural abnormalities, and down-regulation of p53 and overexpression of Bcl2 in the nervous tissues.

Tramadol for osteoarthritis

BACKGROUND

Tramadol is often prescribed to treat pain and is associated physical disability in osteoarthritis (OA). Due to the pharmacologic mechanism of tramadol, it may lead to fewer associated adverse effects (i.e. gastrointestinal bleeding or renal problems) compared to non-steroidal anti-inflammatory drugs (NSAIDs). This is an update of a Cochrane Review originally published in 2006.

OBJECTIVES

To determine the benefits and harms of oral tramadol or tramadol combined with acetaminophen or NSAIDs in people with osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase databases, as well as the US National Institutes of Health and World Health Organization trial registries up to February 2018. We searched the LILACS database up to August 2015.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of tramadol, or tramadol in combination with acetaminophen (paracetamol) or NSAIDs versus placebo or any comparator in people with osteoarthritis.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane.

MAIN RESULTS

We included 22 RCTs (11 more than the previous review) of which 21 RCTs were included in meta-analyses for 3871 participants randomized to tramadol alone or tramadol in combination with another analgesic and 2625 participants randomized to placebo or active control. Seventeen studies evaluated tramadol alone and five evaluated tramadol plus acetaminophen. Thirteen studies used placebo controls and eleven studies used active controls (two trials had both placebo and active arms). The dose of tramadol ranged from 37.5 mg to 400 mg daily; all doses were pooled. Most trials were multicenter with a mean duration of two months. Participants were predominantly women with hip or knee osteoarthritis, with a mean age of 63 years and moderate to severe pain. There was a high risk of selection bias as only four trials reported both adequate sequence generation and allocation concealment. There was a low risk for performance bias as most studies blinded participants. There was a high risk of attrition bias as 10/22 trials showed incomplete outcome data. Most of the trials were funded by the pharmaceutical industry.Moderate quality evidence (downgraded due to risk of bias) indicated that tramadol alone and in combination with acetaminophen had no important benefit on pain reduction compared to placebo control (tramadol alone: 4% absolute improvement, 95% confidence interval (CI) 3% to 5%; 8 studies, 3972 participants; tramadol in combination with acetaminophen: 4% absolute improvement, 95% CI 2% to 6%; 2 studies, 614 participants).Fifteen out of 100 people in the tramadol group improved by 20% (which corresponded to a clinically important difference in pain) compared to 10/100 in the placebo group (5% absolute improvement). Twelve out of 100 people improved by 20% in the tramadol in combination with acetaminophen group compared to 7/100 in the placebo group (5% absolute improvement).Moderate quality evidence (downgraded due to risk of bias) indicated that tramadol alone and in combination with acetaminophen led to no important benefit in physical function compared to placebo (tramadol alone: 4% absolute improvement, 95% CI 2% to 6%; 5 studies, 2550 participants; tramadol in combination with acetaminophen: 4% absolute improvement, 95% CI 2% to 7%; 2 studies, 614 participants).Twenty-one out of 100 people in the tramadol group improved by 20% (which corresponded to a clinically important difference in physical function) compared to 16/100 in the placebo group (5% absolute improvement). Fifteen out of 100 people improved by 20% in the tramadol in combination with acetaminophen group compared to 10/100 in the placebo group (5% absolute improvement).Moderate quality evidence (downgraded due to risk of bias) indicated that, compared to placebo, there was a greater risk of developing adverse events with tramadol alone (risk ratio (RR) 1.34, 95% CI 1.24 to 1.46; 4 studies, 2039 participants) and tramadol in combination with acetaminophen compared to placebo (RR 1.91, 95% CI 1.32 to 2.76; 1 study, 308 participants). This corresponded to a 17% increase (95% CI 12% to 23%) with tramadol alone and 22% increase (95% CI 8% to 41%) with tramadol in combination with acetaminophen.The three most frequent adverse events were nausea, dizziness and tiredness. Moderate quality evidence (downgraded due to risk of bias) indicated that there was a greater risk of withdrawing from the study because of adverse events with tramadol alone compared to placebo (RR 2.64, 95% CI 2.17 to 3.20; 9 studies, 4533 participants), which corresponded to a 12% increase (95% CI 9% to 16%).Low quality evidence (downgraded due to risk of bias and inconsistency) indicated that there was a greater risk of withdrawing from the study because of adverse events with tramadol in combination with acetaminophen compared to placebo (RR 2.78, 95% CI 1.50 to 5.16; 2 studies, 614 participants), which corresponded to a 8% absolute improvement (95% CI 2% to 19%).Low quality evidence (downgraded due to risk of bias and imprecision) indicated that there was a greater risk of developing serious adverse events with tramadol alone compared to placebo (110/2459 participants with tramadol compared to 22/1153 participants with placebo; RR 1.78, 95% CI 1.11 to 2.84; 7 studies, 3612 participants), which corresponded to a 1% increase (95% CI 0% to 4%). There were no serious adverse events reported in one small study (15 participants) of tramadol with acetaminophen compared to placebo.

AUTHORS' CONCLUSIONS

Moderate quality evidence indicates that compared to placebo, tramadol alone or in combination with acetaminophen probably has no important benefit on mean pain or function in people with osteoarthritis, although slightly more people in the tramadol group report an important improvement (defined as 20% or more). Moderate quality evidence shows that adverse events probably cause substantially more participants to stop taking tramadol. The increase in serious adverse events with tramadol is less certain, due to the small number of events.

The Diagnosis and Therapy of Degenerative Knee Joint Disease: Expert Consensus from the Chinese Pain Medicine Panel

At present, there are many constantly updated guidelines and consensuses on the diagnosis and treatment of osteoarthritis both at home and abroad. The recommendations established using methods of evidence-based medicine has experienced strict research on controlling bias and promoting reproduction rate. As a result, the previous evidence was reevaluated, and a lot of changes were provoked in the diagnosis and treatment concept of osteoarthritis. However, several methods not recommended by foreign guidelines are still in use in the current clinical practice in China. On the one hand, Chinese experts have not reached extensive consensus on whether it is necessary to make changes according to foreign guidelines. On the other hand, almost all the current relevant guidelines are on osteoarthritis, but the lesions around knee joints which, as a whole, bear the largest weight in human body, cannot be ignored. For this purpose, Chinese Association for the Study of Pain (CASP) organized some leading experts to formulate this Chinese Pain Specialist Consensus on the diagnosis and treatment of degenerative knee osteoarthritis (DKOA) in combination with the guidelines in foreign countries and the expert experience of clinical practice in China. The consensus, which includes the definition, pathophysiology, epidemiology, clinical manifestation, diagnostic criteria, and treatments of DKOA, is intended to be used by first-line doctors, including pain physicians to manage patients with DKOA.

Anti-inflammatory effects of an injectable copolymer of fatty acids (Ara 3000 beta®) in joint diseases

Background

In inflammatory joint disease, such as osteoarthritis or arthritis, there is an increased level of pro-inflammatory cytokines, such as interleukin-1β. These cytokines stimulate the expression and release of matrix metalloproteases (MMP), leading to the degradation of cartilage extracellular matrix and subsequently mobility difficulty and suffering for patients. The aim of this study was to examine the therapeutic potential of a fatty acid copolymer in in vitro and in vivo models of cartilage inflammation.

Methods

Inflammation was mimicked in vitro by treatment of human articular chondrocytes with interleukin-1β. Effects of a co-treatment with a copolymer of fatty acids (Ara 3000 beta®) were determined by evaluating MMP production by RT-PCR and ELISA, NO release by Griess assay, and PGE2 expression by ELISA. In addition, in vivo analysis (evolution of weight and edema) were also performed after injection of Freund adjuvant in rats treated or not with the copolymer of fatty acids.

Results

The copolymer of fatty acids clearly reduces inflammation in joint. In vitro, it impairs IL1 stimulated-MMP production and release, as well as the release of NO and PGE2 and the activation of NFκB. Furthermore, in vivo experiments using adjuvant induced-arthritis corroborates the anti-inflammatory effects of the copolymer of fatty acids, with a reduction of edemas, erythemas and ankylosis in arthritic rats.

Conclusions

The results support the hypothesis that a copolymer of fatty acids, such as Ara 3000 beta®, is a powerful anti-inflammatory compounds, suggesting that it has a potential for preventing cartilage degradation associated with chronic inflammatory joint disease.

Glucosamine for osteoarthritis: biological effects, clinical efficacy, and safety on glucose metabolism

Osteoarthritis is a chronic degenerative disorder that currently represents one of the main causes of disability within the elderly population and an important presenting complaint overall. The pathophysiologic basis of osteoarthritis entails a complex group of interactions among biochemical and mechanical factors that have been better characterized in light of a recent spike in research on the subject. This has led to an ongoing search for ideal therapeutic management schemes for these patients, where glucosamine is one of the most frequently used alternatives worldwide due to their chondroprotective properties and their long-term effects. Its use in the treatment of osteoarthritis is well established; yet despite being considered effective by many research groups, controversy surrounds their true effectiveness. This situation stems from several methodological aspects which hinder appropriate data analysis and comparison in this context, particularly regarding objectives and target variables. Similar difficulties surround the assessment of the potential ability of glucosamine formulations to alter glucose metabolism. Nevertheless, evidence supporting diabetogenesis by glucosamine remains scarce in humans, and to date, this association should be considered only a theoretical possibility.

Non-surgical management of early knee osteoarthritis

Conservative approach is usually the first choice for the management of the knee degeneration processes, especially in the phase of the disease recognized as early osteoarthritis (OA) with no clear lesions or associated abnormalities requiring to be addressed surgically. A wide spectrum of treatments is available, from non-pharmacological modalities to dietary supplements and pharmacological therapies, as well as minimally invasive procedures involving injections of various substances aiming to restore joint homeostasis and provide clinical improvement and possibly a disease-modifying effect. Numerous pharmaceuticals have been proposed, but since no therapy has shown all the characteristic of an ideal treatment, and side effects have been reported at both systemic and local level, the use of pharmacological agents should be considered with caution by assessing the risk/benefit ratio of the drugs prescribed. Both patients and physicians should have realistic outcome goals in pharmacological treatment, which should be considered together with other conservative measures. A combination of these therapeutic options is a more preferable scenario, in particular considering the evidence available for non-pharmacological management. In fact, exercise is an effective conservative approach, even if long-term effectiveness and optimal dose and administration modalities still need to be clarified. Finally, physical therapies are emerging as viable treatment options, and novel biological approaches are under study. Further studies to increase the limited medical evidence on conservative treatments, optimizing results, application modalities, indications, and focusing on early OA will be necessary in the future. Level of evidence IV.

Carbonic anhydrase inhibitors. Inhibition of human erythrocyte isozymes I and II with a series of antioxidant phenols

The inhibition of two human cytosolic carbonic anhydrase (hCA, EC 4.2.1.1) isozymes I and II, with a series of phenol derivatives was investigated by using the esterase assay, with 4-nitrophenyl acetate as substrate. 2,6-Dimethylphenol, 2,6-diisopropylphenol (propofol), 2,6-di-t-butylphenol, butylated hydroxytoluene, butylated hydroxyanisole, vanillin, guaiacol, di(2,6-dimethylphenol), di(2,6-diisopropylphenol), di(2,6-di-t-butylphenol), and acetazolamide showed K(I) values in the range of 37.5-274.5 microM for hCA I and of 0.29-113.5 microM against hCA II, respectively. All these phenols were non-competitive inhibitors with 4-nitrophenylacetate as substrate. Some antioxidant phenol derivatives investigated here showed effective hCA II inhibitory effects, in the same range as the clinically used sulfonamide acetazolamide, and might be used as leads for generating enzyme inhibitors possibly targeting other CA isoforms which have not been yet assayed for their interactions with such agents.

Cost-effectiveness analysis for joint pain treatment in patients with osteoarthritis treated at the Instituto Mexicano del Seguro Social (IMSS): Comparison of nonsteroidal anti-inflammatory drugs (NSAIDs) vs. cyclooxygenase-2 selective inhibitors

Background

Osteoarthritis (OA) is one of the main causes of disability worldwide, especially in persons >55 years of age. Currently, controversy remains about the best therapeutic alternative for this disease when evaluated from a cost-effectiveness viewpoint. For Social Security Institutions in developing countries, it is very important to assess what drugs may decrease the subsequent use of medical care resources, considering their adverse events that are known to have a significant increase in medical care costs of patients with OA. Three treatment alternatives were compared: celecoxib (200 mg twice daily), non-selective NSAIDs (naproxen, 500 mg twice daily; diclofenac, 100 mg twice daily; and piroxicam, 20 mg/day) and acetaminophen, 1000 mg twice daily. The aim of this study was to identify the most cost-effective first-choice pharmacological treatment for the control of joint pain secondary to OA in patients treated at the Instituto Mexicano del Seguro Social (IMSS).

Methods

A cost-effectiveness assessment was carried out. A systematic review of the literature was performed to obtain transition probabilities. In order to evaluate analysis robustness, one-way and probabilistic sensitivity analyses were conducted. Estimations were done for a 6-month period.

Results

Treatment demonstrating the best cost-effectiveness results [lowest cost-effectiveness ratio $17.5 pesos/patient ($1.75 USD)] was celecoxib. According to the one-way sensitivity analysis, celecoxib would need to markedly decrease its effectiveness in order for it to not be the optimal treatment option. In the probabilistic analysis, both in the construction of the acceptability curves and in the estimation of net economic benefits, the most cost-effective option was celecoxib.

Conclusion

From a Mexican institutional perspective and probably in other Social Security Institutions in similar developing countries, the most cost-effective option for treatment of knee and/or hip OA would be celecoxib.

In vitro inhibition of salicylic acid derivatives on human cytosolic carbonic anhydrase isozymes I and II

The inhibition of two human cytosolic carbonic anhydrase (hCA, EC 4.2.1.1) isozymes, hCA I and II, with a series of salicylic acid derivatives was investigated by using the esterase method with 4-nitrophenyl acetate as substrate. IC(50) values for sulfasalazine, diflunisal, 5-chlorosalicylic acid, dinitrosalicylic acid, 4-aminosalicylic acid, 4-sulfosalicylic acid, 5-sulfosalicylic acid, salicylic acid, acetylsalicylic acid (aspirin) and 3-metylsalicylic acid were of 3.04 microM, 3.38 microM, 4.07 microM, 7.64 microM, 0.13 mM, 0.29 mM, 0.42 mM, 0.56 mM, 2.71 mM and 3.07 mM for hCA I and of 4.49 microM, 2.70 microM, 0.72 microM, 2.80 microM, 0.75 mM, 0.72 mM, 0.29 mM, 0.68 mM, 1.16 mM and 4.70 mM for hCA II, respectively. Lineweaver-Burk plots were also used for the determination of the inhibition mechanism of these substituted phenols, most of which were noncompetitive inhibitors with this substrate. Some salicylic acid derivatives investigated here showed effective hCA I and II inhibitory activity, and might be used as leads for generating enzyme inhibitors eventually targeting other isoforms which have not been assayed yet for their interactions with such agents.

Targeting pleiotropin to treat osteoarthritis

Pleiotropin (PTN) is a secreted heparin-binding peptide expressed in mesodermal and neuroectodermal cells during development, but rarely in adult tissues. Although PTN is abundant in fetal or juvenile cartilage, it is undectable in mature cartilage. However, PTN is re-expressed in chondrocytes in early stages of osteoarthritis where it is detectable in situ and in synovial fluids from patients. PTN enhances chondrogenesis by stimulation of extra-cellular matrix synthesis, reduction of degrading matrix metalloproteases and induction of their inhibitors; PTN also slightly reduces pro-inflammatory factors, such as nitric oxide and vascular endothelial growth factor. Furthermore, PTN stimulates chondrocyte clustering and proliferation. Thus, PTN appears to mediate repair and protective processes in osteoarthritic cartilage and appears to be a promising factor to treat osteoarthritis.