Asthma I Flashcards
Ashtmatics have activated?
T-cells
what is used in Asthma tx?
1) Bronchodilators
2) Anti-inflammatory drugs
Main Bronchodilators used in the tx of Asthma
β2-ADRENOCEPTOR AGONISTS
1) SABA –> salbutamol (albuterol), metaproterenol, terbutaline
2) LABA –> salmeterol and formoterol
MoA of β2 -ADRENOCEPTOR AGONISTS
β2- adrenoceptor stimulation –> smooth muscle relax –> ——– -> inhibit mediator release from mast cells –> ———– from monocytes –> Increase —- by action on cilia
β2- adrenoceptor stimulation –> smooth muscle relax –> bronchodilation –> Bronchodilation Inhibit mediator release from mast cells. Inhibit TNF-α release from monocytes
–> Increase mucus clearance by action on cilia
Administration of Salbutamol (Albuterol), Salmeterol and Formoterol
- Given by inhalation (Aerosol, Powder, Nebulizer)
- Also orally and IV
3 Short-acting adrenergic β2 agonists (SABA) drugs used for symptomatic releif of Asthma
salbutamol (albuterol), metaproterenol, terbutaline
(Duration of action is 3–5 h)
duration of action of LABA
8-12 hrs
duration of action of SABA
3-5 hrs
2 Longer-acting adrenergic
β2 agonists (LABA) drugs used in the tx of Asthma
salmeterol and formoterol
(Duration of action is 8–12 h)
Clinical uses of Albuterol
Short-acting used for Acute symptoms of Asthma
(Wheezing, chest pain, coughing, dizinessn fainting)
Clinical uses of Salmeterol and Formoterol
Long-acting, used to contorl Acute symptoms of Asthma
AE of Salbutemol, Salmeterol and Formoterol
1) Tremor (most common)
2) Arrythmias
3) Anxiety
4) headache
5) Tachycardia
6) high doses - lactic acidosis and Hypokalaemia
Contraindications of β2 -ADRENOCEPTOR AGONISTS
CV disease
- drugs cause Arrythmias and Tachycardia
Asthma drugs that block leukotriene receptors (CysLT1)
Montelukast and zafirlukast
* not as effective as β2-ADRENOCEPTOR AGONISTS
MoA of Montelukast and zafirlukast
Antileukotrines –> block leukotriene receptors (CysLT1)
CU of Montelukast and zafirlukast
1) Exercise-induced asthma
2) Adjunct to tx
3) Alternative to tx w/ ICS (inhaled corticosteroids) for Chronic asthma
MoA of Cysteneil (CysTL 1/2) Leukotrienes and their receptors
1) Potent spasmogens of bronchial muscle
2) Increase mucus secretion
3) May contribute to bronchial hyperactivity
Do Montelukast ,zafirlukast and Zileuton provide symptomatic relief in Asthma patients?
NO
AntiLeukotriene drugs
1) Montelukast, zafirlukast
2) Zileuton
(Oral drugs)
MoA of Zileuton
5-LOX inhibitor –> decreases the conversion of Arachidonic acid to leukotrienes
AE of Antileukorienes
* Montelukast , zafirlukast, Zileuton
1) Hepatotoxicity (esp Zileuton)
2) headache
3) GI disturbances
4) increased risk of respiatory tract infection
**SOS: Neuropsychotic events**
Clinical uses of Zileuton
Adjunctive to steroids in the tx of Asthma
Mthyelxanthines used in the tx of Asthma
Theophylline-oral (also used as aminophylline- IV)
MoA of Theophylline
Methylxanthine –> bronchodilation by inhibiting PDE IV
* It also has anti-inflammatory actions
Clinical uses of Theophylline
1) w/ steroids, in patients whose asthma does not respond adequantly to β2-receptor agonists.
2) in addition to steroids in COPD
3) IV theophylline+ ehtylenendiamine (to increase H2O solubility) in acute severe asthma
AE of Theophylline
1) Nausea, diarrhea
2) Insomnia, nervousness
3) Serious dysrhythmias (cardiotoxicity), which can be fatal
4) Seizures (neurotoxicity), which can be fatal
what hepatic enzyme meatbolizes Theophylline
CYP450,
Therfore limited use due to narrowe theraputic index (causes neuro-/cardio-toxicity)
Glucocorticoids used in the tx of Acute severe Asthma
Beclometasone, budesonide, fluticasone, mometasone, ciclesonide, flunisolide
What drugs are used to prevent the progression of Chronic Asthma, and is effective in acute sever asthma?
budesonide, fluticasone
(Glucocorticoids)
Administration of budesonide, fluticasone
inhalation with a metered-dose or dry powder inhaler
1st line therapy for chronic asthma?
budesonide, fluticasone
**Main anti-inflammatory drugs in asthma for all ages**
MoA of Glucocorticoids
Anti-inflammatories –> inhibit the synthesis of virtually all Cytokines and inflammatory agents
AE of Glucorticoids such as budesonide and fluticasone, used for chronic asthma therapy
1) Oral thrush –> Oropharyngeal candidiasis
2) Sore throat and croaky voice
How can oral thrush be prevented when using inhaled Glucocorticoids
1) “Spacing” devices
2) Rinse mouth after use
Treatment approach for sever acute asthma
O2, Nebulised salbutamol, IV hydrocortisone followed by a course of oral prednisolone
* Additional measures: Nebulised ipratropium, IV salbutamol, IV aminophylline, Abx (if bacterial infection is present)
* medical emergency
Biological therapy in Asthma
Omalizumab
- Tezelelumab
- Benralizumab
- Dupilumab
- umab
**
MoA of Omalizumab?
Anti-inflammatory biological therapy
Anti-IgE
