Areas of emerging interest in analgesia: cardiovascular complications

Why paracetamol (acetaminophen) is a suitable first choice for treating mild to moderate acute pain in adults with liver, kidney or cardiovascular disease, gastrointestinal disorders, asthma, or who are older

Acute pain is among the most common reasons that people consult primary care physicians, who must weigh benefits versus risks of analgesics use for each patient. Paracetamol (acetaminophen) is a first-choice analgesic for many adults with mild to moderate acute pain, is generally well tolerated at recommended doses (≤4 g/day) in healthy adults and may be preferable to non-steroidal anti-inflammatory drugs that are associated with undesirable gastrointestinal, renal, and cardiovascular effects. Although paracetamol is widely used, many patients and physicians still have questions about its suitability and dosing, especially for older people or adults with underlying comorbidities, for whom there are limited clinical data or evidence-based guidelines. Inappropriate use may increase the risks of both overdosing and inadequate analgesia. To address knowledge deficits and augment existing guidance in salient areas of uncertainty, we have researched, reviewed, and collated published evidence and expert opinion relevant to the acute use of paracetamol by adults with liver, kidney, or cardiovascular diseases, gastrointestinal disorders, asthma, or/and who are older. A concern is hepatotoxicity, but this is rare among adults who use paracetamol as directed, including people with cirrhotic liver disease. Putative epidemiologic associations of paracetamol use with kidney or cardiovascular disease, hypertension, gastrointestinal disorders, and asthma largely reflect confounding biases and are of doubtful relevance to short-term use (<14 days). Paracetamol is a suitable first-line analgesic for mild to moderate acute pain in many adults with liver, kidney or cardiovascular disease, gastrointestinal disorders, asthma, and/or who are older. No evidence supports routine dose reduction for older people. Rather, dosing for adults who are older and/or have decompensated cirrhosis, advanced kidney failure, or analgesic-induced asthma that is known to be cross-sensitive to paracetamol, should be individualized in consultation with their physician, who may recommend a lower effective dose appropriate to the circumstances.

The Characteristics of Pain in Patients Diagnosed with Depression and Heart Failure

Heart failure (HF) is a costly and growing health problem that is routinely complicated by chronic pain and depression. The purpose of this paper is to describe the characteristics of pain and pain management in depressed HF patients. In this descriptive cross-sectional study, we analyzed data from 62 participants with depression and class II-IV HF. Study variables of interest were collected from the Brief Pain Inventory, Beck Depression Inventory, and Rand-36. Almost all participants (98%) had some pain in the past month and most had pain in the last 24 hours (66%). The median pain score was 4 (0-10 scale) with the majority reporting moderate to severe pain. The median pain interference score was 4.42 (0-10 scale) with the majority reporting moderate to extreme interference. Medication to treat pain was used by all participants who reported pain, with only 5% also using nonpharmacologic treatment. The majority of participants reported moderate or severe pain while also having moderate to extreme pain interference. Nonpharmacologic pain treatments were severely underused. Women were more likely to have higher levels of pain intensity and more pain interference than men, suggesting that additional screening for the impact of pain is especially important in women. The wide variety of body areas affected, along with moderate to high intensity pain and considerable interference scores reported, indicate that pain was ineffectively treated. Nonpharmacologic treatments should be considered to decrease the impact of pain.

The patterns of toxicity and management of acute nonsteroidal anti-inflammatory drug (NSAID) overdose

The nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for their analgesic, anti-inflammatory and antipyretic actions. They are commonly taken in overdose in many areas of the world. The majority of patients with acute NSAID overdose will remain asymptomatic or develop minor self-limiting gastrointestinal symptoms. However, serious clinical sequelae have been reported in patients with acute NSAID overdose and these include convulsions, metabolic acidosis, coma and acute renal failure. There appear to be some differences between the NSAIDs in terms of the relative risk of these complications; in particular mefenamic acid is most commonly associated with convulsions. The management of these serious clinical features is largely supportive and there are no specific antidotes for acute NSAID toxicity.

The changing role of non-opioid analgesic techniques in the management of postoperative pain

Given the expanding role of ambulatory surgery and the need to facilitate an earlier hospital discharge, improving postoperative pain control has become an increasingly important issue for all anesthesiologists. As a result of the shift from inpatient to outpatient surgery, the use of IV patient-controlled analgesia and continuous epidural infusions has steadily declined. To manage the pain associated with increasingly complex surgical procedures on an ambulatory or short-stay basis, anesthesiologists and surgeons should prescribe multimodal analgesic regimens that use non-opioid analgesics (e.g., local anesthetics, nonsteroidal antiinflammatory drugs, cyclooxygenase inhibitors, acetaminophen, ketamine, alpha 2-agonists) to supplement opioid analgesics. The opioid-sparing effects of these compounds may lead to reduced nausea, vomiting, constipation, urinary retention, respiratory depression and sedation. Therefore, use of non-opioid analgesic techniques can lead to an improved quality of recovery for surgical patients.

Selecting nonprescription analgesics

Worldwide, there has been an emerging patient demand for access to efficient drugs without consulting a doctor and obtaining a prescription. As a result, there has been an expanding movement of prescription-only drugs to over-the-counter (OTC) status. An increasing number of drugs are becoming available OTC, empowering patients to treat themselves. Where the principle of empowering individuals to treat themselves can fail is when consumers lack the knowledge to do so safely. This potentially applies to the self-selection of analgesic drugs by consumers. When used inappropriately, these drugs pose significant risks. The nonsteroidal antiinflammatory drugs (NSAIDs) are associated with many adverse reactions, interactions, and contraindications in a number of patient groups, even at OTC doses. In particular, in the elderly, the high incidence of cardiovascular and gastrointestinal disease, coupled with age-related decline in renal function and multiple medication use, all warrant extra caution with the use of NSAIDs and make paracetamol the simple analgesic drug of first choice. Despite the possibility of hepatotoxicity in overdose, paracetamol represents a better all-round option for most patients requiring OTC analgesic therapy.

Drug Interactions with Paracetamol

Paracetamol (acetaminophen) is one of the most commonly used analgesic antipyretic drugs worldwide, and it is widely available by prescription and over the counter (OTC). Fortunately, few clinically significant drug interactions have been documented. There is probable potentiation of hepatotoxicity following an overdose from the paracetamol metabolite NAPQI by enzyme-inducing drugs. There is considerable controversy regarding the possible interaction with warfarin in its potential to increase its anticoagulant effects because of discrepancies between observational studies and those in healthy volunteers. Otherwise, no serious adverse drug interactions with therapeutic doses of paracetamol have been confirmed in humans. Because the absorption of paracetamol is so dependent on gastric emptying, other drugs that alter gastric emptying can change its pharmacokinetics; but this would not cause serious adverse effects. Although animal experiments have demonstrated that many compounds can modify paracetamol hepatotoxicity, these are unlikely to be important at therapeutic doses.

Acetaminophen as symptomatic treatment of pain from osteoarthritis

Osteoarthritis is a major public health burden. The incidence of osteoarthritis increases with advancing age. Symptomatic treatments aimed at alleviating the pain and thereby restoring joint function form the basis of the treatment. The chronic course requires long-term treatment with special attention to minimizing the side effects of drugs. Acetaminophen has a good risk/benefit ratio that has prompted international consensus panels to recommend its use as first-line therapy in dosages of up to 4 g/day. This review discusses safety and efficacy data from randomized double-blind trials of acetaminophen used to alleviate pain caused by osteoarthritis.

Analgesia and the patient with osteoarthritis

Osteoarthritis is the most common form of arthritis, its prevalence increasing with age: as much as 80% of the population over 75 years show radiologic signs of the condition. Symptoms include pain, stiffness, and functional impairment; however, not all patients are symptomatic. Management starts with nonpharmacologic interventions, followed by pharmacologic means, and ultimately by surgical intervention. The management is multidisciplinary and is tailored to the needs of the individual patient. It is, therefore, a good model of collaborative care: multidisciplinary management of a chronic condition for which the patients themselves coordinate the use of the management options, with information and guidance from health care professionals and written materials, as needed. Guidelines for the management of osteoarthritis have been developed and are applied in different continents. These guidelines are based on searches of the literature and evidence-based interpretation, in combination with expert opinion. Pharmacologic management guidelines state that based on its overall efficacy, toxicity profile, and cost, paracetamol-acetaminophen should be tried first and, if successful, should be used as the preferred long-term analgesic. In patients who do not experience adequate symptomatic relief with paracetamol-acetaminophen, alternative or additional pharmacologic agents should be considered, especially nonsteroidal anti-inflammatory drugs (NSAIDs). When the combination of paracetamol-acetaminophen with NSAIDs fails, tramadol may be given. Most patients with osteoarthritis are able, after discussion with their physician, to manage their symptoms themselves. They make use of educational occupational, and physical advisers, and they use their medication on demand. The basis of this self-administered pharmacologic management is paracetamol-acetaminophen, sometimes in combination with NSAIDs. A promising option for the future is the development of symptomatic slow-acting drugs for osteoarthritis that possess structure-modifying properties.