Leukotriene Receptor Antagonists
CLASS
- Leukotriene Receptor Antagonists
- example is Montelukast
MECHANISM OF ACTION
- Leukotrienes are central to the pathophysiology of acute asthma
- Leukotrienes are synthesized from arachiodonic acid and released from membrane phospholipids when inflammatory cells are activated
- Ltb4, LtD4, LtC4 and LE4 bind receptor (CysLT) on mast cells, eosinophils and alveolar macrophages produce the features of asthma
- Smooth muscle contraction and bronchoconstriction
- chemotaxis and activation: leukocyte infiltration and stimulation of production of pro-inflammatory cytokines
- Capillary leak and airway oedema
- Proliferation of smooth muscle cells and fibroblasts
- LRA -> inhibitors of the leukotriene pathway
- Leukotriene inhibitors are specific for the airway receptors and may block this reaction
ROUTE
- taken PO once or twice daily
USE
- have been shown to have steroid sparing effects
- preventative role in community
- particularly useful in NSAID and aspirin induced asthma
- limited role in ICU
- If a patient is in the recovery phase of an asthma attack and there is a history of frequent attacks then its addition to other preventer medications would be appropriate
- Indicated in management of asthma when inhaled glucocorticoids not tolerated or for patients who have not responded to inhaled glucocorticoids
BENEFICIAL EFFECTS
- shown to reduce the severity of initial response to allergen induced asthma
- attenuates the late and delayed response
- decreases prolonged airway hyperresponsiveness
- improves lung function
- decreases need for beta adrenergic agonists
- fewer symptoms of asthma
- decrease exacerbations
ADVERSE EFFECTS
- side effects – increases LFTs
- interactions – wafarin -> increase INR
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC