The use of analgesics in patients with asthma

An analysis of multidrug multicomponent crystals as tools for drug development

In a typical tablet or capsule formulation, the active drug is often present as a crystalline solid. This solid emerges from the relationships between the individual atoms within the crystal, which confer a distinct set of physical properties. Then, it follows that if we modify the packing arrangement of the individual molecules within these crystals, we can modulate their properties. This can be achieved by crystal engineering. Crystal engineering has also seen teams arrange multiple drug molecules within the same crystal, resulting in dramatic improvements to drug properties in the lab. The success of drugs like SEGLENTIS® and Entresto® have revitalised interest in these forms, but controversy surrounding their translation has prompted this reconsideration of their clinical utility. I reflect on the current academic, clinical, and commercial interest in multidrug multicomponent crystals, drawing parallels with developments pre-Bragg, contributing to a nuanced understanding of the potential and limitations of crystal engineering in pharmaceutical applications.

Asthma Is Associated with Back Pain and Migraine-Results of Population-Based Case-Control Study

(1) Background: Worldwide, asthma, back pain, and migraine are major public health problems due to their high prevalence, effect on the quality of life, and huge economic costs. The association of asthma with an increased risk of these types of pain has been suggested; however, no conclusive results have been obtained to date. The aims of our study were (1) to describe and compare the prevalence of three types of pain localization, namely migraine or frequent headaches (MFH), chronic neck pain (CNP), and chronic low back pain (CLBP), in adults with and without asthma in Spain during the years 2014 and 2020 and (2) to identify which variables were associated with the presence of these types of pain in adults with asthma. (2) Methods: A cross-sectional study and a case-control study were conducted. The 2014 and 2020 European Health Interview Surveys for Spain were used as the data source. (3) Results: A total of 2463 individuals were interviewed and had self-reported asthma. In this group, the prevalence of pain was high, with CLBP (30.9%) being the most common, followed by CNP (26.7%) and MFH (13.3%). All types of pain remained stable from 2014 to 2020. In both surveys, the women with asthma reported a remarkably higher prevalence of all the types of pain analyzed than the men with asthma. After matching by age and sex, the prevalence of all pain types was significantly higher in the patients with asthma than in the matched individuals without asthma. Multivariable adjustment showed that asthma increased the likelihood of CNP by 1.45 times (OR 1.45; 95% CI 1.19-1.76), that of CLBP by 1.37 times (OR 1.37; 95% CI 1.11-1.64), and that of MFH by 1.19 times (OR 1.19; 95% CI 1.02-1.51). The three types of pain analyzed were associated with the female sex and worse self-rated health. (4) Conclusions: Among the men and women with asthma, the prevalence of all the pain types was high and remained stable over time. The prevalence was higher and the severity was greater among the women with asthma than among the men with asthma. The prevalence of any pain was significantly higher in people with asthma than in the sex-age-matched individuals without asthma. Multivariable analysis showed that the variables associated with the reporting of the three types of pain in people with asthma were female sex, worse self-reported health, and self-reported mental illness.

Use of pharmaceuticals amongst athletes tested by Anti-Doping Norway in a five-year period

Introduction

The aim of the study was to map the use of pharmaceuticals by Norwegian athletes registered on doping control forms (DCFs) in a five-year period to examine general and some class specific use of pharmaceuticals across sports and athlete levels.

Method

Anonymous data from DCFs collected in 2015-2019 were manually entered into a database using the Anatomical Therapeutic Chemical (ATC) system for classification of the pharmaceuticals. Variables entered were year of control, gender, age group, athlete level, sport, test type, nationality, and pharmaceuticals (and dietary supplements) used.

Results

Pain killers in the ATC groups M01 A (Nonsteroidal anti-inflammatory drugs - NSAIDs) and N02 B (other analgesics), and anti-asthmatics in ATC groups R03 A and R03 B were the most frequently used pharmaceuticals. National level athletes reported more use of pharmaceuticals (1.4 ± 1.7 pharmaceuticals per form) than recreational level athletes (0.9 ± 1.2). The highest proportion of DCFs containing information about at least one pharmaceutical were found in speed skating (79.1%), alpine skiing (74.0%), rowing (72.4%) and cross-country skiing (71.7%). Painkillers were most frequently used in muscular endurance sports (30.4% and 21.2 % for M01A and N02 B, respectively) and ball and team sports (17.9% and 17.0%). Use of hypnotics was reported from ice-hockey players and alpine skiers in around 8% of the cases.

Coclusion

Use of anti-asthmatics was most often reported amongst athletes specially exposed to cold, chemicals and heavy endurance training. Athletes in specialized sports requiring high levels of strength and/or endurance reported a higher use of pharmaceuticals out-of-competition compared to in-competition, while there was no such difference in complex sports, such as team, gymnastic, aiming and combat sports.

Comparative Efficacy of Analdent (Herbal Analgesic Preparation) and Aceclofenac on Pain Intensity After Tooth Extraction: A Split-Mouth Randomized Clinical Trial

Background and Aim

Pain management following tooth extraction is crucial in minimizing patient suffering and risk of infection and hastening the recovery. Safety issues with routinely prescribed drugs such as NSAIDs for pain management call for search of an effective and safe alternative. Advances in the field of alternative medicine have led to the use of various natural products for pain management in the field of dentistry. The aim of the study was to compare the efficacy between the analdent and aceclofenac in terms of alleviation of post-operative pain and facial swelling after extraction of tooth.

Methods

A split-mouth randomized clinical trial was conducted on 22 participants in the age range of 13-25 years requiring extraction of first permanent premolars for orthodontic reason. The extraction sites were randomized to receive either analdent or aceclofenac post-orthodontic extraction. Post-extraction dental pain was assessed after 8 h, 24 h, 48 h and 72 h post-operatively using a visual analog scale, and incidence of swelling was recorded.

Results

Pain score showed a significant reduction (p = 0.001) post-operatively within analdent (herbal drug) group as well as Zerodol (aceclofenac) group. However, there was no significant difference in pain intensity between the two groups at each interval. Two participants in analdent group and one participant in aceclofenac group reported swelling after 8 h of extraction which subsided after cold pack application.

Conclusion

Analdent was found to be equally effective as aceclofenac in managing pain after the tooth extraction with relatively no side effects.CTRI Registration Number: CTRI/2020/ 03/024296 dated 27/03/2020.

Frequency and Knowledge of Analgesics Self-Use and Their Adverse Effects in the Eastern Province of Saudi Arabia

Background Paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used over-the-counter (OTC) medications, both locally in Saudi Arabia (SA) and globally. They are widely available and can be easily obtained; however, the potential health risks of these drugs are well-documented. This study aimed to measure the frequency of analgesics' self-use and assess the general population's knowledge of their adverse effects. Methodology This is a descriptive, cross-sectional study that was conducted through an online self-administered questionnaire. It targeted adults who are non-healthcare professionals living in the eastern province of SA. Results The sample consisted of 345 participants, of which 196 (56.8%) were male and 149 (43.2%) were female. The most self-used medication was paracetamol at 91%, followed by ibuprofen at 38.8%. Although the prevalence of self-use was high, a low frequency of repeated use was evident, as 49.3% of the participants rarely used them and 19.4% used them only every few months. There was a significant association between the female gender, lower levels of education, and a higher frequency of repeated use of analgesics. About 54.5% of the participants recognized three side effects or fewer, while 90 (26.1%) of them showed knowledge about four to six side effects. Conclusions Considering that paracetamol and NSAIDs are easily procurable OTC, the knowledge of the general population about their harmful adverse effects needs to be enhanced, specifically that of the most vulnerable patient groups.

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.

Risk of wheezing and asthma exacerbation in children treated with paracetamol versus ibuprofen: a systematic review and meta-analysis of randomised controlled trials

Background

Paracetamol and ibuprofen are the most commonly used medications for fever and pain management in children. While the efficacy appears similar with both drugs, there are contradictory findings related to adverse events. In particular, incidence of wheezing and asthma among children taking paracetamol compared to ibuprofen, remain unsettled.

Methods

We conducted a meta-analysis of randomized controlled trials (RCTs) that compared wheezing and asthma exacerbations in children taking paracetamol versus ibuprofen. A comprehensive search was conducted in five databases. RCTs reporting on cases of wheezing or asthma exacerbations in infants or children after the administration of paracetamol or ibuprofen were included. The pooled effect size was estimated using the Peto’s odds ratio.

Results

Five RCTs with 85,095 children were included in the analysis. The pooled estimate (OR 1.05; 95%CI 0.76–1.46) revealed no difference in the odds of developing asthma or presenting an exacerbation of asthma in children who received paracetamol compared to ibuprofen. When the analysis was restricted to RCTs that examined the incidence of asthma exacerbation or wheezing, the pooled estimate remained similar (OR 1.01; 95%CI 0.63–1.64). Additional bias adjusted quality effect sensitivity model yielded similar results (RR 1.03; 95%CI 0.84–1.28).

Conclusion

Although, Ibuprofen and paracetamol appear to have similar tolerance and safety profiles in terms of incidence of asthma exacerbations in children, we suggest high quality trials with clear definition of asthma outcomes after receiving ibuprofen or paracetamol at varying doses with longer follow-up are warranted for any conclusive finding.

Pre- and post-operative management of dental implant placement. Part 1: management of post-operative pain

Although dental implant placements have high success rates and a low incidence of morbidity, post-operative pain and complications with the healing process have been reported. There is little guidance available regarding optimal pre- and post-operative management of dental implant placement. This first paper discusses the mechanisms of pain associated with dental implant placement and offers guidance to clinicians on optimal pre- and post-operative pain management regimes. The second paper aims to discuss pre- and post-operative means of reducing the risk of early healing complications.

Prenatal and infant paracetamol exposure and development of asthma: the Norwegian Mother and Child Cohort Study

BACKGROUND

Paracetamol exposure has been positively associated with asthma development. The relative importance of prenatal vs infant exposure and confounding by indication remains elusive. We examined the association of prenatal and infant (first 6 months) paracetamol exposure with asthma development while addressing confounding by indication.

METHODS

We used information from the Norwegian Mother and Child Cohort Study, including 53169 children for evaluation of current asthma at 3 years, 25394 for current asthma at 7 years and 45607 for dispensed asthma medications at 7 years in the Norwegian Prescription Database. We calculated adjusted relative risks (adj. RR) and 95% confidence intervals (CI) using log-binomial regression.

RESULTS

There were independent modest associations between asthma at 3 years with prenatal paracetamol exposure (adj. RR 1.13; 95% CI: 1.02-1.25) and use of paracetamol during infancy (adj. RR 1.29; 95% CI: 1.16-1.45). The results were consistent for asthma at 7 years. The associations with prenatal paracetamol exposure were seen for different indications (pain, respiratory tract infections/influenza and fever). Maternal pain during pregnancy was the only indication that showed an association both with and without paracetamol use. Maternal paracetamol use outside pregnancy and paternal paracetamol use were not associated with asthma development. In a secondary analysis, prenatal ibuprofen exposure was positively associated with asthma at 3 years but not asthma at 7 years.

CONCLUSIONS

This study provides evidence that prenatal and infant paracetamol exposure have independent associations with asthma development. Our findings suggest that the associations could not be fully explained by confounding by indication.

Aspirin and multiple sclerosis

Aspirin is widely used to lessen the risks of cardiovascular events. Some studies suggest that patients with multiple sclerosis have an increased risk for some cardiovascular events, for example, venous thromboembolism and perhaps ischemic strokes, raising the possibility that aspirin could lessen these increased risks in this population or subgroups (patients with limited mobility and/or antiphospholipid antibodies). However, aspirin causes a small increased risk of hemorrhagic stroke, which is a concern as it could potentially worsen a compromised blood-brain barrier. Aspirin has the potential to ameliorate the disease process in multiple sclerosis (for example, by limiting some components of inflammation), but aspirin also has the potential to inhibit mitochondrial complex I activity, which is already reduced in multiple sclerosis. In an experimental setting of a cerebral ischemic lesion, aspirin promoted the proliferation and/or differentiation of oligodendrocyte precursors, raising the possibility that aspirin could facilitate remyelination efforts in multiple sclerosis. Other actions by aspirin may lead to small improvements of some symptoms (for example, lessening fatigue). Here we consider potential benefits and risks of aspirin usage by patients with multiple sclerosis.

Prenatal and infant exposure to acetaminophen and ibuprofen and the risk for wheeze and asthma in children

BACKGROUND

Several studies have reported an association between use of over-the-counter antipyretics during pregnancy or infancy and increased asthma risk. An important potential limitation of these observational studies is confounding by indication.

OBJECTIVES

We investigated the association of antipyretic intake during pregnancy and during the first year of life (infancy) with asthma-related outcomes before and after controlling for early-life respiratory tract infections.

METHODS

We included 1490 mother-child pairs in Project Viva, a longitudinal prebirth cohort study. We categorized prenatal acetaminophen exposure as the maximum intake (never, 1-9 times, or ≥10 times) in early pregnancy or midpregnancy and ibuprofen intake as presence or absence in early pregnancy. We expressed intake of antipyretics in infancy as never, 1 to 5 times, 6 to 10 times, or more than 10 times. We examined the associations of acetaminophen and ibuprofen (per unit increase in exposure category) during pregnancy and infancy with wheeze, asthma, and allergen sensitization in early childhood (3-5 years of age, n = 1419) and midchildhood (7-10 years of age, n = 1220).

RESULTS

Unadjusted models showed an increased asthma risk in early childhood for higher infant acetaminophen (odds ratio [OR], 1.21; 95% CI 1.04-1.41) and ibuprofen (OR, 1.35; 95% CI, 1.19-1.52) intake. Controlling for respiratory tract infections attenuated estimates for acetaminophen (OR, 1.03; 95% CI, 0.88-1.22) and ibuprofen (OR, 1.19; 95% CI, 1.05-1.36). Prenatal acetaminophen was associated with increased asthma (OR, 1.26; 95% CI, 1.02-1.58) in early childhood but not midchildhood.

CONCLUSIONS

Adjustment for respiratory tract infections in early life substantially diminished associations between infant antipyretic use and early childhood asthma. Respiratory tract infections should be accounted for in studies of antipyretics and asthma to mitigate bias caused by confounding by indication.

Aspirin sensitivity and coronary artery disease: implications for the practicing cardiologist

Aspirin is the most commonly used antiplatelet agent in patients with coronary artery disease (CAD). It continues to play a key role as an antiplatelet agent given its long-term safety, efficacy and low cost. Aspirin or NSAID hypersensitivity is not an uncommon occurrence and can vary from generalized urticaria and angioedema to exacerbation of upper and lower respiratory tract reactions. It is not uncommon for clinicians to avoid using aspirin and alternative agents when encountering aspirin hypersensitivity among CAD patients. However, given the critical role of aspirin in CAD patients, particularly among those who receive the drug-eluting stents, aspirin desensitization can be useful. This article highlights the importance of aspirin desensitization, the mechanism and the process involved. We draw attention to recently described rapid desensitization protocols and how they can be more useful than the old procedure.

The time delay between drug intake and bronchospasm for nonsteroidal antiinflammatory drugs sensitive patients

A study was performed to assess the time between drug intake and drug induced hypersensitivity reaction for patients sensitive to nonsteroidal antiinflammatory drugs (NSAID) in clinical patient history and after oral provocation tests. Drug hypersensitivity ENDA questionnaires were filled for the patients with suspected sensitivity to NSAID. Oral provocation tests were performed with suspected NSAID according to the ENDA/EAACI recommendations. There were 76 patients with history of hypersensitivity reactions after use of NSAID enrolled in the study. Recorded were 154 hypersensitivity reactions to NSAID in the clinical history. In the clinical history median time of immediate reactions (76 cases, 81%) between drug intake and bronchospasm was 20 minutes [15-30 minutes]. Median time of nonimmediate reactions (18 cases, 19%) was 120 minutes [120-390 minutes]. There were 50 oral provocation tests performed, 14 of them (28%) were positive. Median time between drug intake and immediate reactions (8; 57% of cases) was 22.5 minutes [20-30 minutes] and median time of nonimmediate reactions (6; 43% of cases) was 167.5 minutes [125-206.25 minutes]. Time delay between drug intake and bronchospasm in the clinical history and after oral provocation test was not statistically different.

The prevalence of aspirin-induced asthma in Saudian asthmatic patients

BACKGROUND

Aspirin-induced asthma (AIA), is a distinct clinical syndrome affecting some asthmatic patients. Although the name of the condition relates to aspirin, it is well established that affected patients are cross-sensitive to all non-steroidal anti-inflammatory drugs (NSAIDs).

OBJECTIVES

Assessing the prevalence of AIA among Saudian asthmatic patients.

METHODS

This is a retrospective study of the medical records of asthmatic patients.

RESULTS

The prevalence of AIA in the patients studied was found to be 12.6%. Statistical analyses indicated that AIA was associated with more severe asthma [odds ratio (OR) (95% Confidence interval (CI)) in Group I cases 2.86 (1.24 to 6.59) respectively (p<0.05)]. The results showed that some allergic conditions were significantly more common in Group I for allergic rhinitis (OR=2.19, 95% CI 0.89-5.37, p<0.05), pollinosis (OR=1.59, 95% CI 0.85-2.98, p<0.05) for antibiotic allergy (OR=1.25, 95% CI 0.65-2.41, p<0.05) and for atopic dermatitis (OR=1.34, 95% CI 0.70-2.55, p<0.05). Family history of allergy had a more significant role in Group I cases (OR=1.27, 95% CI 0.68-2.37, p<0.05). No gender difference on asthma severity was detected in either group (Chi(2)=2.19, p>0.05).

CONCLUSION

The prevalence of respiratory symptoms triggered by aspirin/NSAID use was 12.6% in the asthmatics studied. AIA appears to be a significant problem and further investigations of the mechanisms of these responses and the possible link between this syndrome and other allergic co-morbidities are required.

Randomised aspirin assignment and risk of adult-onset asthma in the Women's Health Study

BACKGROUND

Randomised data in men show a small but significant reduction in the risk of adult-onset asthma among those given aspirin. The results from an observational study in women suggest that frequent use of aspirin decreases the risk of adult-onset asthma, but randomised data in women are lacking. A study was undertaken to test the effect of 100 mg aspirin or placebo on alternate days on the risk of adult-onset asthma in the Women's Health Study.

METHODS

A randomised, double-blind, placebo-controlled clinical trial of aspirin and vitamin E was performed in apparently healthy women with no indication or contraindication to aspirin therapy and no history of asthma at study entry. Female health professionals self-reported an asthma diagnosis on yearly questionnaires.

RESULTS

Among 37 270 women with no reported history of asthma prior to randomisation and during 10 years of follow-up, there were 872 new cases diagnosed with asthma in the aspirin group and 963 in the placebo group (hazard ratio 0.90; 95% CI 0.82 to 0.99; p = 0.027). This apparent 10% lower relative risk of incident adult-onset asthma among those assigned to aspirin was significantly modified by body mass index, with no effect in women with a body mass index of >/=30 kg/m2. The effect of aspirin on adult-onset asthma was not significantly modified by age, smoking status, exercise levels, postmenopausal hormone use or randomised vitamin E assignment.

CONCLUSIONS

In this large randomised clinical trial of apparently healthy adult women, administration of 100 mg aspirin on alternate days reduced the relative risk of a newly reported diagnosis of asthma.

[Ibuprofen in childhood: evidence-based review of efficacy and safety]

Ibuprofen is the non-steroidal anti-inflammatory drug most prescribed for the treatment of fever and moderate pain in childhood. Its analgesic and antipyretic efficacy is now well documented: at equal doses ibuprofen appears slightly more effective than acetaminophen in the treatment of fever and is equivalent for analgesia. However, adverse effects should be taken into account in the choice between ibuprofen and acetaminophen. Lot of studies (case reports, cohort studies, case-control studies and one multicenter double-blind randomized control trial) have reported ibuprofen adverse effects at therapeutics doses. These data suggest there is an increased risk of invasive group A streptococcal infection after chickenpox and of acute renal failure in case of hypovolemia after a treatment by ibuprofen. Gastroduodenal and hemorrhagic adverse events could also happen, but the causality with ibuprofen is not demonstrated. Therefore, ibuprofen is not recommended for the treatment of fever or moderate pain during chickenpox or during a disease with a risk of dehydration, until other pharmacoepidemiology studies more accurately quantify the risk of adverse events of ibuprofen in children.

A teenager with severe asthma exacerbation following ibuprofen

Aspirin-sensitive asthma, aspirin-intolerant asthma, aspirin- (or non-steroidal anti-inflammatory drug [NSAID]) exacerbated respiratory disease are terms for a disorder commonly described as affecting adults aged > 30y. With this perception, ibuprofen was administered for postoperative pain management to a 17-year-old boy with allergic rhinitis and previous severe asthma (at a time when well controlled), who then had a severe asthma exacerbation. Analysis of the literature in response to this case highlights four points: 1) NSAID-exacerbated asthma is not only a disorder of adults; it occurs in up to of 2% in asthmatic children, approaching probably 30% in older children with severe asthma and nasal disease. 2) The asthmatic reaction is dose-dependent and can occur with sub-therapeutic doses. Oral NSAID/aspirin challenge should be conducted in an environment where a severe asthma exacerbation can be appropriately managed. 3) The therapeutic use of non-selective [COX-1 preferential] NSAIDs should be avoided when sensitivity is known or suspected in adults and teenagers with severe asthma and chronic rhinosinusitis or nasal polyps. Use of these agents in younger children with mild episodic wheeze is probably safe. 4) Paracetamol use is probably safe, but aspirin-exacerbated respiratory disease may occur with clinical doses in a subgroup of aspirin-exacerbated respiratory disease patients. COX-2 selective inhibitors are probably safe, although this is controversial. Opioids and tramadol are suitable analgesic alternatives for patients with known or suspected susceptibility.

Mechanism of action of paracetamol

Paracetamol (acetaminophen) is generally considered to be a weak inhibitor of the synthesis of prostaglandins (PGs). However, the in vivo effects of paracetamol are similar to those of the selective cyclooxygenase-2 (COX-2) inhibitors. Paracetamol also decreases PG concentrations in vivo, but, unlike the selective COX-2 inhibitors, paracetamol does not suppress the inflammation of rheumatoid arthritis. It does, however, decrease swelling after oral surgery in humans and suppresses inflammation in rats and mice. Paracetamol is a weak inhibitor of PG synthesis of COX-1 and COX-2 in broken cell systems, but, by contrast, therapeutic concentrations of paracetamol inhibit PG synthesis in intact cells in vitro when the levels of the substrate arachidonic acid are low (less than about 5 mumol/L). When the levels of arachidonic acid are low, PGs are synthesized largely by COX-2 in cells that contain both COX-1 and COX-2. Thus, the apparent selectivity of paracetamol may be due to inhibition of COX-2-dependent pathways that are proceeding at low rates. This hypothesis is consistent with the similar pharmacological effects of paracetamol and the selective COX-2 inhibitors. COX-3, a splice variant of COX-1, has been suggested to be the site of action of paracetamol, but genomic and kinetic analysis indicates that this selective interaction is unlikely to be clinically relevant. There is considerable evidence that the analgesic effect of paracetamol is central and is due to activation of descending serotonergic pathways, but its primary site of action may still be inhibition of PG synthesis. The action of paracetamol at a molecular level is unclear but could be related to the production of reactive metabolites by the peroxidase function of COX-2, which could deplete glutathione, a cofactor of enzymes such as PGE synthase.

Ibuprofen and increased morbidity in children with asthma: fact or fiction?

NSAIDs are commonly avoided by patients with aspirin-induced asthma based on the premise that there is a significant cross-reactivity between aspirin and other NSAIDs. However, ibuprofen, a NSAID sold over the counter in most countries, is commonly given to children for relief of fever and mild-to-moderate pain. Consequently, increased risk of acute bronchospasm induced by ibuprofen in children with asthma remains a persistent concern. More recently, the assumption that children with asthma are at a greater risk for exacerbations of their disease if they take ibuprofen has been questioned. There is little evidence to measurably increases morbidity in the great majority of children with asthma. In addition, recent evidence suggest that ibuprofen measurably increases morbidity in the great majority of [corrected] children with asthma. Given the infrequent occurrence of aspirin/NSAID sensitivity in children with asthma, it seems reasonable to allow the use of ibuprofen in this population unless there is a personal or family history of aspirin-induced asthma. In addition, the inflammatory pathogenesis of asthma, anti-inflammatory effect of ibuprofen, and evidence suggesting ibuprofen may reduce morbidity in children with asthma raises the intriguing possibility that ibuprofen might actually have therapeutic benefit for at least some children with asthma.

Tolerability of Paracetamol

The excellent tolerability of therapeutic doses of paracetamol (acetaminophen) is a major factor in the very wide use of the drug. The major problem in the use of paracetamol is its hepatotoxicity after an overdose. Hepatotoxicity has also been reported after therapeutic doses, but critical analysis indicates that most patients with alleged toxicity from therapeutic doses have taken overdoses. Importantly, prospective studies indicate that therapeutic doses of paracetamol are an unlikely cause of hepatotoxicity in patients who ingest moderate to large amounts of alcohol. Controlled clinical trials have found that paracetamol is very well tolerated by the gastrointestinal tract. While variable results have been found in case control studies, most studies have shown no change or a small increase in the relative risk of perforations, ulcer or bleeding in the upper gastrointestinal tract. However, associations between the use of paracetamol and gastrointestinal toxicity, as well as with chronic renal disease and asthma, are very likely to reflect biases in some case control studies. In particular, such biases may be caused by the perceived high tolerability of paracetamol in these diseases. The consequent use of paracetamol in these diseases states then leads to an apparent association between paracetamol and the disease. Despite metabolism of paracetamol to reactive compounds, hypersensitivity reactions are rare, although urticaria occurs in occasional patients. Paracetamol appears to be well tolerated during pregnancy although prospective studies are required.

Systematic review of prevalence of aspirin induced asthma and its implications for clinical practice

OBJECTIVE

To reassess the prevalence of aspirin induced asthma and other issues related to the syndrome.

DATA SOURCES

Biosis, SciSearch (1990 to March 2002), Embase (1974 to March 2002), Medline (1966 to March 2002), Toxline, Derwent Drug File (1964 to March 2002), Conference Papers Index and Inside Conferences, Int'l Pharmaceutical Abstracts, Pharma-Online (1978 to March 2002).

SELECTION CRITERIA

Study type, patient population, and outcome measures. Review was restricted to respiratory responses to analgesics available without prescription.

RESULTS

The prevalence of aspirin induced asthma was highest when determined by oral provocation testing (adults 21%, 95% confidence interval 14% to 29%; children 5%, 0% to 14%) than by verbal history (adults 3%, 2% to 4%; children 2%, 1% to 3%). Cross sensitivity to doses of over the counter non-steroidal anti-inflammatory drugs was present in most patients with aspirin induced asthma: ibuprofen, 98%; naproxen, 100%; and diclofenac, 93%. The incidence of cross sensitivity to paracetamol among such patients was only 7%.

CONCLUSIONS

Aspirin induced asthma in adults is more prevalent than previously suggested. When there is a clinical necessity to use aspirin or a non-steroidal anti-inflammatory drug and there is uncertainty about safety, oral provocation testing should be performed.

Paracetamol and asthma

Paracetamol (acetaminophen) is one of the over-the-counter analgesics that is used frequently for the self-management of some of the common disorders. There seems to be two types of relations between paracetamol and asthma - paracetamol intolerance leading to bronchospasm in analgesic-induced asthmatics; and the relation between asthma and the amount and frequency of consumption of paracetamol. Paracetamol is generally recommended as one of the safer analgesics in both analgesic tolerant and intolerant asthmatics, without the fear of severe bronchospasm that aspirin and other non-steroidal anti-inflammatory drugs can induce in these patients. However, Paracetamol is reported to cross-react with aspirin at a rate of approximately 20-30% in a dose-dependent way. Therefore, it should not be recommended to analgesic intolerant asthmatics, without performing oral provocation tests to prove its safety. The possible association between the amount and frequency of paracetamol consumption and the prevalence and degree of asthma as suggested by some of the recent surveys, needs to be investigated further.