Skip to main content

Acetaminophen causes childhood asthma, researcher argues




Is acetaminophen responsible for the worldwide rise in childhood asthma over the past 30 years? Citing a mounting pile of circumstantial evidence from epidemiologic observational studies, John McBride of Akron’s Children’s Hospital in Ohio believes so, and that it’s time to officially push the worry button.
The theory is that the fear of aspirin-induced Reye’s syndrome in the 1980s resulted in a large increase in the amount of acetaminophen prescribed to children, causing the observed spike in asthma incidence we’ve seen since then. How? Acetaminophen depletes glutathione, an antioxidant peptide that can curb inflammation in the airways. This hypothetical etiology was proposed by Varner back in 1998, and McBride reiterated it in his review in the November Pediatrics, in which he argues the acetaminophen-asthma link is now strong enough that doctors should counsel the parents of children with asthma (or at risk for asthma) to avoid acetaminophen when possible.
Strong words. What’s the evidence?
  • Children who took acetaminophen in the first year of life had a 50% greater risk of developing asthma symptoms, compared to kids who took no acetaminophen, in the“Isaac” observational study of 200,000 children in 31 countries, published in Lancetin 2008. There was a dose-response relationship: children taking acetaminophen monthly had a 3-fold likelihood of asthma symptoms.
  • In an analysis in ERJ in 2000 tracking acetaminophen (paracetamol) sales in 36 countries, amount of paracetamol sold correlated directly with the prevalence of asthma in that country.
  • A 2009 meta-analysis in Chest aggregated 13 observational studies including 425,000 children and adults, and found an odds ratio of 1.63 for asthma and/or wheezing for children and adults who took acetaminophen.
  • Only one randomized trial in Pediatrics 2002 suggests acetaminophen might worsen wheezing or asthma: among 1,879 children taking asthma inhalers, those randomized to take ibuprofen as needed for a febrile illness were less likely to see a doctor for asthma than those randomized to acetaminophen as needed.
Not all Dr. McBride’s colleagues share his confidence in the acetaminophen-asthma link (including the author of the Chest study), pointing out the inherent flaws of these types of association studies. For example, could an unmeasured confounder be responsible for the observed association between acetaminophen and childhood asthma? Viral infections are also arisk factor for development of asthma, and children with viral infections often receive acetaminophen. In a study by Lowe et al in BMJ 2010, controlling for the number of viral infections abolished any independent effect of acetaminophen on risk for childhood asthma.
Longitudinal cohort studies or randomized trials are the only way to answer questions like these with any surety. At least one small randomized trial is underway to test the effects of paracetamol on lung function in children. Clinicaltrials.gov doesn’t show any others listed under acetaminophen or paracetamol and asthma.
McBride JT. The Association of Acetaminophen and Asthma Prevalence and Severity.Pediatrics 2011;128:1181-1185.
Labels:

Comments

Post a Comment

Popular posts from this blog

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more

Lumbar and thoracic epidural in Pediatrics-Technical aspect

The midline approach is most commonly used. The ligamentum   flavum is considerably thinner and less dense in infants than in older children and adults. This makes recognition of engagement in the ligament more difficult and requires both extra care and slower, more deliberate passage of the needle to avoid subarachnoid puncture. The angle of approach to the epidural space is slightly more perpendicular to the plane of the back than in older children and adults, owing to the orientation of the spinous   processes in infants and small children. The loss of resistance technique should be used, but only with saline, not air. There are several reports of venous air embolism in infants and children when air was used to test for loss of resistance Use a short (5 cm) 18-gauge Tuohy needle and a 20- or 21-gauge catheter in infants and children. Epidural kits specifically for infants and children are available Maximum of 0.4 mg/kg/hr of bupivacaine after the initial block is estab...
Post a Comment
Read more