What are the 2 classes of drugs used to treat asthma?
What are the 4 types of bronchodilators?
1. Beta 2 agonists2. Xanthine drugs3. Cysteinyl-leukotriene receptor antagonists4.Muscarinic antagonists
What are the 2 types of anti-inflammatories used to treat asthma?
1. Corticosteroids2. Cromoglicate
Beta 2 agonist description
Potent BronchodilatorsRelax SM directlyMost effective drugs for acute asthmaCan be Short or Long acting
Short acting Beta 2 agonist?
SalbutamolRapid onset of actionTaken as neededInhaledNot suitable as sole therapy
Long acting Beta 2 agonist?
SalmeterolTaken as preventativeInhaledNot suitable for acute attacks
Xanthine drugs summary
Administered orally or IVAct directly on the SM to cause bronchodilationInhibit phosphodiesterases- altering cAMP or cGMP, causing adenosine receptor antagonism
An example of a Xanthine drug?
TheophyllineRapid onset of actionSymptomatic reliefNot suitable for sole therapyLow therapeutic indexS/E's include GIT upset, CNS effects and dysrhthmias
Cysteinyl-leukotriene antagonist summary
Relax SM directly to cause bronchoconstrictionTreats both stages of asthma attackAdministered orallyHigh affinity cysteinyl-leukotriene receptor antagonism
Example of cysteinyl-leukotriene receptor antagonist?
MontelucastUsed for mild asthma, only has 1/3 of Salbutamol's effectsUsed as add on therapy for beta 2 agonists or steroidsFew side effects (GIT upset)
Muscarinic antagonist summary
Weak bronchodilatorsInhaledCompete with ACh at M3 receptorVery few side effectsUsed in children
Example of a muscarinic antagonist?
Used for moderate and severe asthmaModerate- orally. Severe- IV.Bind steroid receptors and influence gene transcription to decrease cytokine production and increase beta 2 receptor production.Decrease inflammatory response, bronchial reactivity and mucosal secretion.Increases airway diameter.
Example of Inhaled Steroid?
Example of systemic steroid?
CromoglicateUsed as a preventative, useless during an attackBlocks bronchoconstriction but doesn't cause bronchodilationInhaledMechanism largely unknown (decreases histamine release?)