Drugs For Bronchial Asthma Flashcards
What is asthma
Asthma is a COPD chxd by reversible bronchospasm and chronic inflammation in the respiratory tract. Symptoms generally include cough, wheezing, chest tightness and shortness of breath.
Pathophysiology of bronchial asthma
The major pathophysiologic mechanism is release of chemical mediators by IgE sensitised mast cells and other cells involved in immune response. Allergens like pollen,dust act as an antigen and activate IgE which sensitive mast cells and lead to their degranulation and thus releasing prostaglandin, leukotrienes , cytokines etc. This would then lead to bronchospasm and increased mucus sectetion
Bronchodilators include
B2 adrenergic agonists
Methylxanthines
Anticholinergics
BAM
The B2 adrenergic agonists
Include the selective and non selective
Selective- INCLUDE
SABA- Salbutamol and terbutaline(salt)
LABA- Salmeterol and formoterol
Non selective- Adrenaline
However dangerous due to its action on B1
Mechanism of action of b2aa
Activate B2 adrenergic receptors of the bronchial smooth muscles leading to an increase in cAMP production that would lead to bronchodilation and reduce release of chemical mediators. They are the mainstay of reversible airway obstruction.
Adverse effects of B2AA
Palpitations
Tachycardia/tremor
Hypokalemia.
SABA can be used in form of a metered dose inhaler T/F
T
Methylxanthines include
Aminophylline
Theophylline
Doxophylline
Mechanism of action of Methylxanthines
They are bronchodilators that act by inhibiting phosphodiesterases which break down cAMP to 5’AMP, thus leading to increased levels of cAMP and subsequent bronchodilation
Adverse effects of mtx
The constant battle of the methylxanthines
Heart: palpitation,tachycardia,hypotension or even death due to cardiac arrythmias
Kidney:diuresis
Git: nausea vomiting gastritis or aggravation of pus
Cns: headache restlessness or even seizures.
Narrow therapeutic index
Uses of Methylxanthines
Bronchial asthma and COPD however rarely used due to adverse effects
Premature apnea in infants- very low dose aminophylline
Anticholinergic drugs include
Ipratropium and tiotropium bromide
This Theophylline of a man😒🙄
Lazy- food delays it’s rate of absorption
Ajebutter- poorly water soluble, can only be taken orally
Amebo-drug interaction
Phenytoin/rifampicin/phenobarbital
Cimetidine/ciprofoxacin/erythromycin.
Cross match of saba and laba
SABA- Acute attacks
Salmeterol- maintenance
Formoterol- prophylaxis
MOA of anticholinergics
Act on muscarinic receptors to block effects of ach on bronchial smooth muscles and cause bronchodilation
Anticholinergics are best effective when administered alone as inhalers. T/F
False, they have slow onset of action and have better effects when administered with b2 agonists
Anti inflammatory agents in the treatment of bronchial asthma include
Corticosteroids
Mast cells stabilisers
The antibodies.
Leukotriene modifiers
Leukotriene Antagonists ibclude
Zafirlukast
Minteleukast
Zileuton
MOA of leukotriene Antagonists
Act by blocking the effects of cysteine leukotrienes
Zileuton exerts selective inhibition of 5-lipoxygenase.
PK of leukotriene Antagonists
Reduce hyper activity
Well absorbed after oral administration
Highly bound to plasma proteins
Less side effects
Mast cells stabilisers include
Sodium chromoglicate,
nedocromil sodium
ketotifen
MOA of mast cell stabilisers
Stabilise mast cells membrane thereby preventing degranulation and release of chemical mediators.
This Sodium chromoglicate is an actual babe 🔥💦
Poorly absorbed orally thus given by inhalation …just inhale her nice perfume
Used for prophylaxis not in acute asthma…no stress
Can also be used in allergic conjunctivitis,dermatitis,rhinitis etc..still an all rounder🔥🔥
Which of the mast cell stabilisers have H1 blocking effect?
Ketotifen
The glucocorticoids include
Inhalational- beclomethasone, budesonide and fluticasone
Systemic- hydrocortisone, prednisolone etc
MOA of glucocorticoids
Secrete lipocortin which inhibits phospholipase A2 and thereby prevents formation of various mediators such as PGs and txas
Thus they have antiallergic, antiinflammatory and immunosuppressant effect
The glucocorticoids do not have direct bronchodilatory effect and thus are given with bronchodilators. T/f
T.
Have synergistic effect when given with LABA asin fluticasone+salmeterol=seritide
Adverse effects of glucocorticoids
Sodium and water retention, htn, muscle weakness,osteoporosis, gastric irritation due to inhibition of COX2
The antiIgE antibody involved in bronchial asthma is known as?
MOA?
Omalizumab
Prevents IgE from binding to mast cells
Thus prophylactic
In asthma, avoid
NBCS
NSAIDS
Badrenergic blockers like propanolol
Cholinergic agents
Sedatives
Drugs for status asthmatics
O-oxygen
Salbutamol nebulised
Hydrocortisone 200mg IV
Ipratropium bromide nebulised
Theophylline
