Pharmacological aspects of successful long-term analgesia

Persistent pain represents a major quality-of-life burden for patients and a challenge for their physician. Chronic pain often arises from multiple tissue sources and involves multiple chemical mediators and pain transmission pathways. Successful long-term pain management requires analgesic regimens that can treat pains of multiple origin and type. Safety and tolerability are also a high priority when prescribing chronic therapy. Recent publications and regulatory developments affecting anti-inflammatory drugs have limited the options available for the management of chronic pain. Major concerns in long-term use of anti-inflammatory drugs include renal toxicity, gastrointestinal ulceration and bleeding and cardiovascular events, which can be of particular concern for elderly patients. Opioid agents avoid the end-organ toxicity seen with anti-inflammatory drugs, but their use may be limited, especially in the long term, by side effects such as constipation or sedation and by concerns about the potential for physical or psychological dependence. Paracetamol (acetaminophen) has a favourable safety and tolerability profile, although exceeding the recommended dose (up to 4 g/day) carries a risk of liver damage. It exerts simultaneous anti-nociception at both spinal and supra-spinal sites, and has shown self-synergy between these two routes of activity. Tramadol, an atypical weak opioid with a multi-modal mechanism of action, inhibits re-uptake of multiple neurotransmitters and has an improved safety and tolerability profile compared with traditional opioids. Rational combinations of analgesic drugs offer a viable approach to managing persistent pain that involves multiple sites or pathways. The combination of paracetamol plus tramadol brings together two well-known analgesics that have different but complementary mechanisms of analgesic action. Laboratory studies have demonstrated that these agents interact to produce synergistic analgesia with a desirable safety/efficacy profile.     

Combination analgesia in 2005 - a rational approach: focus on paracetamol-tramadol

A multimodal (or balanced) approach to anaesthesia is a familiar concept that offers important benefits in the management of both acute and chronic pain. Rational combinations of analgesic agents with different mechanisms of action can achieve improved efficacy and/or tolerability and safety compared with equianalgesic doses of the individual drugs. Combining different agents also enhances efficacy in complex pain states that involve multiple causes. Combinations of paracetamol plus a weak opioid agent are widely used. One such combination, paracetamol plus tramadol, exploits the well-established complementary pharmacokinetics and mechanisms of action of these two drugs. This combination has demonstrated genuine synergy in animal studies and also combines paracetamol's rapid onset of efficacy with tramadol's prolonged analgesic effect. Numerous studies have confirmed the efficacy and tolerability of paracetamol plus tramadol in both acute and chronic pain. As a single-dose treatment for acute post-operative pain, this combination delivers rapid and sustained pain relief that is greater than either agent alone. There is also extensive evidence for efficacy in the long-term management of chronic pain conditions, including osteoarthritis, low back pain and fibromyalgia. In the setting of chronic pain, paracetamol plus tramadol has shown sustained efficacy, safety and tolerability for up to 2 years without the development of tolerance. The efficacy of this combination has been demonstrated as well in respect to reduction of pain intensity and, more importantly, with regard to improvement of function and quality of life and the reduction of disability. Comparative trials have shown that paracetamol plus tramadol has comparable efficacy to paracetamol plus codeine, but with reduced somnolence and constipation compared with the codeine combination. The paracetamol plus tramadol combination is also free of organ toxicity associated with selective and non-selective non-steroidal anti-inflammatory drugs. Hence, paracetamol plus tramadol offers an effective and well-tolerated alternative to anti-inflammatory drugs or other paracetamol plus weak opioid combinations.     

Cox-2 inhibitors and other nonsteroidal anti-inflammatory drugs in the treatment of pain in the elderly.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed therapies for acute and chronic pain in the elderly. NSAIDs are effective in treating many disorders, but their use often is limited by toxicities, especially gastrointestinal and renal toxicity. COX-2 inhibitors are a major therapeutic advance, providing the analgesic and anti-inflammatory activity of NSAIDs, with a significant improvement in gastrointestinal safety. These new agents may be ideal therapies for older patients at risk for NSAID-related gastrointestinal toxicity.     

Rofecoxib as adjunctive therapy for haemophilic arthropathy

Joint haemorrhage and subsequent haemophilic arthropathy are significant complications in haemophilia. The pathophysiology involves inflammation and angiogenesis. Cyclooxygenase-2 (COX-2) inhibitors are anti-inflammatory agents, which have potent anti-inflammatory, anti-angiogenic and analgesic properties yet do not affect platelet function in the manner of traditional non-steroidal anti-inflammatory drugs. These properties make such agents potentially useful as adjunctive therapy in haemophilia. There is only one prior report describing rofecoxib treatment in a single haemophilia patient. Our objectives were to determine the safety and efficacy of rofecoxib in treating acute haemarthrosis, chronic synovitis, target joints and pain. We conducted a retrospective medical record review of patients treated with rofecoxib for acute haemarthrosis, chronic synovitis, target joint or pain. The safety and efficacy of rofecoxib treatment were determined based on subjective patient reports and physical examinations during follow-up clinic visits. A total of 28 patients between 3 and 37 years of age were treated for a total of 42 courses of rofecoxib treatment. All courses were evaluated for safety and 31 for efficacy. Rofecoxib was used for eight acute haemarthrosis, four target joints, seven cases of synovitis and 12 episodes of pain. Efficacy was demonstrated particularly for chronic synovitis and pain and no serious adverse events occurred. This is the largest study to date evaluating COX-2 inhibitors as adjunctive therapy in haemophilia and suggests that these agents may be an important adjunctive therapy in the management of haemophilia.     

A rationale for combining acetaminophen and NSAIDs for mild-to-moderate pain

Analgesic therapy that combines individual agents with different mechanisms of action has potential advantages for the management of mild-to-moderate pain in the outpatient setting. Theoretically, this approach can lead to greater efficacy and fewer adverse events. While the precise mechanism of action for the analgesic effect of acetaminophen remains uncertain, accumulating evidence suggests that its activity resides primarily in the central nervous system. In contrast, the site of action for the analgesic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is predominantly peripheral, within injured or inflamed tissue. Several controlled clinical studies among patients with musculoskeletal conditions, dental pain, or postoperative pain have shown that combinations of acetaminophen and NSAIDs provide additive pain-relieving activity, thereby leading to dose-sparing effects and improved safety. Further studies are warranted to determine the clinical utility and safety of acetaminophen/NSAID combinations as analgesic therapy for common conditions associated with mild-to-moderate pain.     

Pain management today - what have we learned?

Pain is a leading cause of morbidity worldwide, with published data showing its prevalence as high as 50% for chronic pain in the European population. This prevalence is likely to continue to rise, particularly in elderly people with comorbid conditions and complex aetiologies of pain. There is thus a rapidly growing demand for safe and effective pain management. Management of mild-to-moderate pain has traditionally been based upon the use of non-steroidal anti-inflammatory drugs (NSAIDs) and the synthetic non-opioid analgesic paracetamol (acetaminophen), the latter of which acts centrally, inhibiting brain cyclo-oxygenase (COX) and nitric oxide synthase. Both the NSAIDs and paracetamol are effective for mild-to-moderate pain and are widely recommended and used. However, NSAIDs may not be tolerated due to gastrointestinal (GI) symptoms and can result in potentially fatal peptic ulceration and bleeding. Selective COX-2 inhibitors were developed to reduce the GI side effects and complications, but large-scale studies have highlighted another serious potential effect of anti-inflammatory drugs: cardiovascular events. Both the European Medicines Agency (EMEA) and the Food and Drugs Administration (FDA) in the US have issued advice to apply cautions and restrictions when prescribing COX-2 inhibitors, particularly for patients at increased cardiovascular risk and for long-term use. The FDA also applied cardiovascular warnings with regard to nonselective NSAIDs. Both the EMEA and the FDA have recommended using the lowest effective dose for the shortest duration. These concerns and warnings have left physicians seeking safe alternatives to anti-inflammatory drugs for both short- and long-term uses in many patients. These developments have generated a climate of uncertainty in the absence of official guidance on the selection of alternative analgesic regimens. Amongst the possible strategies, combinations of drugs that provide analgesic efficacy at reduced individual doses may confer the optimal risk-benefit ratio for pain management in the long term or in patients at increased cardiovascular risk. Weak opioids devoid of serious organ-damaging effects combined with paracetamol may well be safer for long-term therapy. Fixed-dose combinations of paracetamol with weak opioids, such as codeine, dextropropoxyphene or tramadol are currently available. Paracetamol plus tramadol is an effective and safe multimodal analgesic regimen for the management of both acute and chronic moderate-to-severe pain. Re-evaluating the role of weak opioids, such as tramadol, and combinations in pain management may prove a valuable option for prescribers seeking alternatives to anti-inflammatory drugs.     

Pain management today—what have we learned?

Pain is a leading cause of morbidity worldwide, with published data showing its prevalence as high as 50% for chronic pain in the European population. This prevalence is likely to continue to rise, particularly in elderly people with comorbid conditions and complex aetiologies of pain. There is thus a rapidly growing demand for safe and effective pain management. Management of mild-to-moderate pain has traditionally been based upon the use of non-steroidal anti-inflammatory drugs (NSAIDs) and the synthetic non-opioid analgesic paracetamol (acetaminophen), the latter of which acts centrally, inhibiting brain cyclo-oxygenase (COX) and nitric oxide synthase. Both the NSAIDs and paracetamol are effective for mild-to-moderate pain and are widely recommended and used. However, NSAIDs may not be tolerated due to gastrointestinal (GI) symptoms and can result in potentially fatal peptic ulceration and bleeding. Selective COX-2 inhibitors were developed to reduce the GI side effects and complications, but large-scale studies have highlighted another serious potential effect of anti-inflammatory drugs: cardiovascular events. Both the European Medicines Agency (EMEA) and the Food and Drugs Administration (FDA) in the US have issued advice to apply cautions and restrictions when prescribing COX-2 inhibitors, particularly for patients at increased cardiovascular risk and for long-term use. The FDA also applied cardiovascular warnings with regard to nonselective NSAIDs. Both the EMEA and the FDA have recommended using the lowest effective dose for the shortest duration. These concerns and warnings have left physicians seeking safe alternatives to anti-inflammatory drugs for both short- and long-term uses in many patients. These developments have generated a climate of uncertainty in the absence of official guidance on the selection of alternative analgesic regimens. Amongst the possible strategies, combinations of drugs that provide analgesic efficacy at reduced individual doses may confer the optimal risk–benefit ratio for pain management in the long term or in patients at increased cardiovascular risk. Weak opioids devoid of serious organ-damaging effects combined with paracetamol may well be safer for long-term therapy. Fixed-dose combinations of paracetamol with weak opioids, such as codeine, dextropropoxyphene or tramadol are currently available. Paracetamol plus tramadol is an effective and safe multimodal analgesic regimen for the management of both acute and chronic moderate-to-severe pain. Re-evaluating the role of weak opioids, such as tramadol, and combinations in pain management may prove a valuable option for prescribers seeking alternatives to anti-inflammatory drugs.     

The burden of acute postoperative pain and the potential role of the COX-2-specific inhibitors

Pain has been recognized as a problem of global proportions, and postoperative pain is one of the most common types of pain. Postoperative pain is acute and, although it is preventable and/or treatable, it is often undertreated. Lack of appropriate analgesic management has significant impact on clinical and economic outcomes. Negative clinical outcomes of inadequately managed acute postoperative pain include extended hospitalization, compromised prognosis, higher morbidity and mortality, and the development of a chronic pain state as a result of neuronal plasticity. Although estimating the economic burden of postoperative pain is difficult, this burden is considerable and results from direct costs due to excess health-care resource use, as well as indirect costs due to reduced patient functionality and productivity. These latter factors also have a significant adverse impact on patients' quality of life and may be associated with the development of depression and anxiety. Thus, improved clinical outcomes are dependent not only on the availability of effective drugs but also on their appropriate utilization. A multimodal approach incorporating different drugs and techniques is effective in reducing postoperative pain but is limited by the currently available therapies. The efficacy of opioids is well established, but there are concerns about dependency, respiratory depression and side-effects, which patients often find intolerable. Non-steroidal anti-inflammatory drugs (NSAIDs) are effective as adjunctive medication in a multimodal regimen but are associated with side-effects, such as platelet dysfunction and renal and gastrointestinal toxicity, that have special clinical significance in patients undergoing surgical procedures. Cyclooxygenase-2-specific inhibitors such as celecoxib, rofecoxib and valdecoxib, were developed to provide the efficacy of non-specific NSAIDs while limiting associated toxicity. These agents have demonstrated analgesic efficacy and an opioid-sparing effect in a variety of surgical procedures, suggesting their value as an alternative to non-specific NSAIDs. Further studies are needed to determine the impact of these drugs on clinical and economic outcomes when used in a programme of postsurgical pain management.     

Biologic drugs as analgesics for the management of osteoarthritis

BackgroundBiologic drugs are novel therapeutic agents with demonstrated effectiveness in the management of a variety of chronic inflammatory disorders. Unmet needs in the treatment of chronic pain have led physicians to utilize a similar approach to patients suffering from conditions not characterized by systemic inflammation such as osteoarthritis (OA). The aim of this review is to discuss the current knowledge on the use of commonly used biologic agents [i.e., anti-tumor necrosis factor alpha (anti-TNF alpha) and anti-nerve growth factor (anti-NGF)] for the management of OA.MethodsA narrative literature review of studies investigating the use of biologic agents for the management of osteoarthritis was conducted. We searched MEDLINE and EMBASE for English language publications. A hand-search of reference lists of relevant studies was also performed.ResultsCurrent evidence does not support TNF-alpha inhibition for the management of OA, although a selected subgroup of these patients with a marked inflammatory profile may benefit from this therapy. Anti-NGF therapy has been shown to reduce pain and improve function compared to placebo and non-steroidal anti-inflammatory drugs in OA but concerns remain regarding the safety of such treatment. The discrepant results observed in RCTs of biologic agents may be related to heterogeneity, small sample sizes, and differences in the mode of administration of these drugs.ConclusionAnti-NGF therapy is efficacious for pain in patients with hip and knee OA. Despite the fact that current data suggests that anti-cytokine treatments have limited efficacy in patients with chronic osteoarthritic pain, larger and better designed studies in more selected populations are justified to determine whether such therapeutic approaches can improve outcomes in this disabling condition where our medical treatment armamentarium is relatively poor.     

PDE4 inhibitors in COPD--a more selective approach to treatment

Chronic obstructive pulmonary disease (COPD) is a serious and mounting global public health problem. Although its pathogenesis is incompletely understood, chronic inflammation plays an important part and so new therapies with a novel anti-inflammatory mechanism of action may be of benefit in the treatment of COPD. Cilomilast and roflumilast are potent and selective phosphodiesterase (PDE)4 inhibitors, with an improved therapeutic index compared with the weak, non-selective PDE inhibitor, theophylline. Unlike theophylline, which is limited by poor efficacy and an unfavourable safety and tolerability profile, the selective PDE4 inhibitors are generally well tolerated, with demonstrated efficacy in improving lung function, decreasing the rate of exacerbations and improving quality of life, with proven anti-inflammatory effects in patients with COPD. Theophylline is a difficult drug to use clinically, requiring careful titration and routine plasma monitoring due to the risk of toxic side effects, such as cardiovascular and central nervous system adverse events, with dose adjustments required in many patients, including smokers, the elderly and some patients on concomitant medications. In contrast, the selective PDE4 inhibitors are convenient medications for both patient and physician alike. Hence these agents represent a therapeutic advance in the treatment of COPD, due to their novel mechanism of action and potent anti-inflammatory effects, coupled with a good safety and tolerability profile.     

A turbulent decade for NSAIDs: update on current concepts of classification, epidemiology, comparative efficacy, and toxicity

Non-steroidal anti-inflammatory drugs (NSAIDs) represent a diverse class of drugs and are among the most commonly used analgesics for arthritic pain worldwide, though long-term use is associated with a spectrum of adverse effects. The introduction of cyclooxygenase-2-selective NSAIDs early in the last decade offered an alternative to traditional NSAIDs with similar efficacy and improved gastrointestinal tolerability; however, emerging concerns about cardiovascular safety resulted in the withdrawal of two agents (rofecoxib and valdecoxib) in the mid-2000s and, subsequently, in an overall reduction in NSAID use. It is now understood that all NSAIDs are associated with some varying degree of gastrointestinal and cardiovascular risk. Guidelines still recommend their use, but little is known of how patients use these agents. While strategies and guidelines aimed at reducing NSAID-associated complications exist, there is a need for evidence-based algorithms combining cardiovascular and gastrointestinal factors that can be used to aid treatment decisions at an individual patient level.     

Update on guidelines for the treatment of chronic musculoskeletal pain

Chronic musculoskeletal pain is a major—and growing—burden on today’s ageing populations. Professional organisations including the American College of Rheumatology (ACR), American Pain Society (APS) and European League Against Rheumatism (EULAR) have published treatment guidelines within the past 5 years to assist clinicians achieve effective pain management. Safety is a core concern in all these guidelines, especially for chronic conditions such as osteoarthritis that require long-term treatment. Hence, there is a consensus among recommendations that paracetamol should be the first-line analgesic agent due to its favourable side effect and safety profile, despite being somewhat less effective in pain relief than anti-inflammatory drugs. Cyclooxygenase-2 (COX-2)-selective anti-inflammatory drugs were developed with the goal of delivering effective pain relief without the serious gastrointestinal (GI) side effects linked with traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs). Clinical trial evidence supported these benefits, and COX-2 inhibitors were widely adopted, both in clinical practice and in official guidelines. Recently, accumulating data have linked COX-2 inhibitors with serious cardiovascular and/or cardiorenal effects and/or serious cutaneous adverse reactions (SCARs), particularly at anti-inflammatory doses or when used long term. Regulatory authorities in both Europe and the USA have responded to these data with the withdrawal of rofecoxib and valdecoxib, and the strengthening of prescribing advice on all anti-inflammatory drugs. COX-2 inhibitors and non-selective NSAIDs should now be used with increased caution in patients at increased cardiovascular and/or cardiorenal risk, e.g., patients with congestive heart failure, hypertension, etc. Regulatory advice and good clinical practice are to use anti-inflammatory drugs at the lowest effective dose and for the shortest possible time. There are as yet no updated official guidelines that incorporate these new data and regulatory advice. An international multidisciplinary panel, the Working Group on Pain Management, has generated new recommendations for the treatment of moderate-to-severe musculoskeletal pain. These guidelines, formulated in response to recent developments concerning COX-2 inhibitors and other NSAIDs, focus on paracetamol as the baseline drug for chronic pain management; when greater analgesia is desired, the addition of weak opioids is recommended based on a preferable GI and cardiovascular profile, compared with non-steroidal anti-inflammatory drugs.     

Update on guidelines for the treatment of chronic musculoskeletal pain

Chronic musculoskeletal pain is a major - and growing - burden on today's ageing populations. Professional organisations including the American College of Rheumatology (ACR), American Pain Society (APS) and European League Against Rheumatism (EULAR) have published treatment guidelines within the past 5 years to assist clinicians achieve effective pain management. Safety is a core concern in all these guidelines, especially for chronic conditions such as osteoarthritis that require long-term treatment. Hence, there is a consensus among recommendations that paracetamol should be the first-line analgesic agent due to its favourable side effect and safety profile, despite being somewhat less effective in pain relief than anti-inflammatory drugs. Cyclooxygenase-2 (COX-2)-selective anti-inflammatory drugs were developed with the goal of delivering effective pain relief without the serious gastrointestinal (GI) side effects linked with traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs). Clinical trial evidence supported these benefits, and COX-2 inhibitors were widely adopted, both in clinical practice and in official guidelines. Recently, accumulating data have linked COX-2 inhibitors with serious cardiovascular and/or cardiorenal effects and/or serious cutaneous adverse reactions (SCARs), particularly at anti-inflammatory doses or when used long term. Regulatory authorities in both Europe and the USA have responded to these data with the withdrawal of rofecoxib and valdecoxib, and the strengthening of prescribing advice on all anti-inflammatory drugs. COX-2 inhibitors and non-selective NSAIDs should now be used with increased caution in patients at increased cardiovascular and/or cardiorenal risk, e.g., patients with congestive heart failure, hypertension, etc. Regulatory advice and good clinical practice are to use anti-inflammatory drugs at the lowest effective dose and for the shortest possible time. There are as yet no updated official guidelines that incorporate these new data and regulatory advice. An international multidisciplinary panel, the Working Group on Pain Management, has generated new recommendations for the treatment of moderate-to-severe musculoskeletal pain. These guidelines, formulated in response to recent developments concerning COX-2 inhibitors and other NSAIDs, focus on paracetamol as the baseline drug for chronic pain management; when greater analgesia is desired, the addition of weak opioids is recommended based on a preferable GI and cardiovascular profile, compared with non-steroidal anti-inflammatory drugs.     

Licofelone--clinical update on a novel LOX/COX inhibitor for the treatment of osteoarthritis

Licofelone, a competitive inhibitor of 5-lipoxygenase, cyclooxygenase (COX)-1 and COX-2, is currently in clinical development for the treatment of osteoarthritis (OA). Licofelone decreases the production of proinflammatory leukotrienes and prostaglandins-which are involved in the pathophysiology of OA and in gastrointestinal (GI) damage induced by NSAIDs-and has the potential to combine good analgesic and anti-inflammatory effects with excellent GI tolerability. Initial endoscopy data in healthy volunteers have demonstrated that licofelone is well tolerated and has a GI safety profile similar to placebo and significantly better than naproxen. These tolerability results were confirmed in patients with OA in two separate randomized studies. Furthermore, a long-term study (52 weeks) has shown that licofelone is at least as effective as naproxen in the treatment of OA. Licofelone also appears to be as effective as the selective COX-2 inhibitor celecoxib in the treatment of the signs and symptoms of OA. Licofelone has a GI safety profile similar to that of celecoxib, but may offer the advantage of fewer incidences or worsening of peripheral oedema. Preliminary data have also shown that licofelone coadministration with low-dose aspirin does not lead to increased GI toxicity. The emerging clinical data for licofelone indicate that it is an effective and well-tolerated therapy that could offer safety advantages over current treatment options, and that it could be suitable for the long-term treatment of a broad spectrum of patients with OA.     

Treatment of osteoarthritis with acetaminophen: Efficacy, safety, and comparison with nonsteroidal anti-inflammatory drugs

Osteoarthritis represents a major public health problem with limited effective treatment. Nonsteroidal antiinflammatory drugs (NSAIDs) are widely used to alleviate symptoms such as pain and stiffness. However, these drugs are associated with an increased risk for the development of adverse sequelae, including serious upper gastrointestinal side effects such as symptomatic ulcers, perforation, obstruction, and gastrointestinal bleeding. The simple analgesic acetaminophen has been found to be effective in alleviating pain in patients with osteoarthritis in a placebo-controlled trial, and several trials have evaluated its efficacy and safety compared with NSAIDs. This article reviews data regarding the efficacy and safety of acetaminophen in the treatment of osteoarthritis from randomized, controlled, clinical trials, focusing on studies that compared acetaminophen with NSAIDs. In addition, literature on physician and patient preferences in this area are examined. In summary, judicious use of analgesic agents as pharmacologic therapy in patients with osteoarthritis will achieve satisfactory pain relief in most cases. Acetaminophen merits a trial as initial terapy in patients with mild to moderate pain, based on cost-effectiveness and safety profile.     

Management of chronic pain in the elderly: focus on transdermal buprenorphine

Chronic pain in the elderly is a significant problem. Pharmacokinetic and metabolic changes associated with increased age makes the elderly vulnerable to side effects and overdosing associated with analgesic agents. Therefore the management of chronic cancer pain and chronic nonmalignant pain in this growing population is an ongoing challenge. New routes of administration have opened up new treatment options to meet this challenge. The transdermal buprenorphine matrix allows for slow release of buprenorphine and damage does not produce dose dumping. In addition the long-acting analgesic property and relative safety profile makes it a suitable choice for the treatment of chronic pain in the elderly. Its safe use in the presence of renal failure makes it an attractive choice for older individuals. Recent scientific studies have shown no evidence of a ceiling dose of analgesia in man but only a ceiling effect for respiratory depression, increasing its safety profile. It appears that transdermal buprenorphine can be used in clinical practice safely and efficaciously for treating chronic pain in the elderly.     

Chronic pain. Clinical management of common causes of geriatric pain

Effective management of chronic pain in older persons is attainable, although unnecessarily elusive. A host of factors can impede assessment and drug management, including impaired cognitive function, multiple potential causes of pain, pharmacokinetics and pharmacodynamics unique to the geriatric population, and clinician anxiety regarding analgesic addiction. In the geriatric population, some of the most prevalent chronic pain management cases involve osteoarthritis, low back pain, and neuropathy. Effective pain management is achieved with analgesics (acetaminophen and nonsteroidal anti-inflammatory drugs), opioids, non-opioid agents (e.g., tricyclic antidepressants, anticonvulsants) and invasive techniques (corticosteroid epidural injections/nerve blocks).     

Assessment and management of chronic hepatitis B

An understanding of the natural history of CHB is critical for the management of the liver disease. Three clinical patterns with different clinical outcomes are recognized: HBeAg-positive CHB, HBeAg-negative CHB,and inactive CHB. Patients with elevated aminotransferase levels and HBV DNA greater than 105 viral copies per mL in serum and with features of chronic hepatitis on liver biopsy are candidates for therapy regardless of HBeAg status. Multiple host and viral factors and safety profiles of current therapies need to be considered carefully before recommending therapy.There appears to be no role for HBV genotyping in the management of patients. Three antiviral agents are approved for use against CHB infection:IFN-a, lamivudine, and adefovir. Efficacy is moderate at best and is limited by the poor tolerability of IFN and the development of resistance, coupled with concerns regarding the long-term safety with nucleoside analogs. Several new nucleoside and nucleotide analogs and novel agents are at various stages of development as potential therapies for CHB. The ideal compound would be one that is active against all replicative intermediates of the virus and has a low toxicity profile. Despite current shortcomings, the future of therapy for HBV is promising, as newer therapeutic options are being developed based on an understanding of the HBV life cycle.     

Preferential COX-2 inhibition: its clinical relevance for gastrointestinal non-steroidal anti-inflammatory rheumatic drug toxicity

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of arthritis and pain. These drugs tend to cause significant side effects, however, including gastric and intestinal toxicity. The mechanism of action of NSAIDs is through their inhibition of the key enzyme of prostaglandin biosynthesis, the cyclooxygenase. Recently, two forms of cyclooxygenase have been found to exist: COX-1 and COX-2, the constitutive and inducible forms, respectively. COX-1 exists in the stomach, intestine, kidneys and platelets, while COX-2, the inducible form, is expressed during inflammation. The therapeutic effects of NSAIDs are largely the result of inhibition of the enzyme cyclooxygenase-2 (COX-2), whereas the toxic effects (e.g., gastrointestinal, renal and platelet effects) are primarily due to the inhibition of COX-1. Individual NSAIDs show different potencies against COX-1 compared with COX-2 and this explains the variations in the side effects of NSAIDs at their anti-inflammatory doses. Drugs with high potency against COX-2 and a better COX-2-/COX-1 activity ratio will have anti-inflammatory activity with fewer gastrointestinal side effects. In contrast piroxicam and indomethacin, which drugs have a much higher potency against COX-1 than against COX-2, are amongst those with the highest gastrointestinal toxicity. Based on these findings, COX-2 seems to be an ideal target for the development of new anti-inflammatory drugs. Several compounds with preferential or specific COX-2 inhibiting properties have been synthesized and evaluated in pre-clinical and clinical studies i.e. Meloxicam, Celecoxib, MK-966, Flusolid and L-745, 337. The COX-2 selectivity of these novel NSAIDs relate well to their favorable gastrointestinal tolerability profile. Clinical trials have shown meloxicam and celecoxib to be as effective as currently available NSAIDs, but with an improved gastrointestinal tolerability profile. Further clinical trials and large-scale postmarketing surveillance programs are needed, however, to confirm the potential therapeutic benefits of these novel preferential or specific COX-2 inhibitors.     

Selective cyclooxygenase-2 inhibitors: after the smoke has cleared

An enormous amount of fanfare and marketing preceded the introduction of selective inhibitors of cyclooxygenase-2 to the marketplace. These drugs were purported to offer equivalent anti-inflammatory and analgesic effects to conventional non-steroidal anti-inflammatory drugs without causing gastrointestinal injury. Now that there is considerable clinical experience with four drugs of this class having been available for at least two years, it is worthwhile re-visiting some of the original claims to determine whether selective cyclooxygenase-2 inhibitors have thus far lived up to their promise. In short, selective cyclooxygenase-2 inhibitors have proven to be somewhat safer in terms of gastrointestinal toxicity, than some (but not all) conventional non-steroidal antiinflammatory drugs. However their efficacy of the selective cyclooxygenase inhibitors has not always matched that of the conventional nonsteroidal anti-inflammatory drugs and there are significant safety concerns with some of the new drugs that deserve very careful consideration.