Respiratory Pharmacology 2

What are the 2 classes of drugs used to treat asthma?

BronchodilatorsAnti-inflammatories

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?

Ipratropium Bromide

Corticosteroid Summary

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?

Beclomethasone(Spacer)

Example of systemic steroid?

PrednisoneOrally

Cromoglicate summary

CromoglicateUsed as a preventative, useless during an attackBlocks bronchoconstriction but doesn't cause bronchodilationInhaledMechanism largely unknown (decreases histamine release?)