Asthma Pharmacology Flashcards
what are the drugs used as relievers
SABAs
LABAs
CystLT antagonists
What is the role of reliever drugs in asthma
Act as bronchodilators
What drugs are used as preventers in asthma
Glucocorticoids
Cromoglicate
Humanised monoclonal IgE
What is the role of preventer drugs in asthma
Act as anti-inflammatory
Reduce airway inflammation
Which drug is used for both relieving and prevention in asthma
Methylxanthines
what is the main role of beta 2 adrenoreceptor agonists
act as physiological antagonists of all spasminogens
What is an example of a SABA
Salbutamol
What is the first line treatment for mild, intermittent asthma
SABAs
What effects does a SABA cause on the airways
bronchial smooth muscle relaxation
increase mucus clearance
decrease mediator release from mast cells and monocytes
What are some side effects of SABAs
fine tremor
tachycardia
arrhythmia
hypokalaemia
What is an example of LABA
Salmeterol, formoterel
When would a LABA be prescribed
useful in nocturnal asthma
Which other drugs should LABAs be used with
Glucocorticoids
Why can asthmatics not use non-selective beta agonists (e.g. propranolol)
Risk of bronchospasm
What is an example of CysLT1 receptor antgonist
Montelukast
How do CysLT1 receptor antagonists work
They act competitively at CysLT1 receptors to block CysLTs causing smooth muscle contraction, mucus secretion and oedema
examples of CysLTs
LTC4
LTD4
LTE4
What are CysLTs derived from
mast cells
What is the result of using CysLT antagonist
bronchodilation (early phase)
Anti-inflammatory (late phase)
What types of asthma are CysLT1 receptor antagonists effective in
mild persistent asthma (as add on therapy)
severe asthma (in combination with corticosteroids)
Antigen induced and exercise induced bronchospasm
What are 2 examples of methylxanthines
theophylline and aminophylline
what is the effect of methyxantines
bronchodilation
anti-inflammatory
inhibit mediator release from mast cells
increase mucus clearance
how do methyanthines improve lung ventilation
increase diaphragmatic contractility and reduce fatigue
why are methylxanthines problematic
very narrow therapeutic window
adverse effects in both therapeutic and supra-therapeutic concentrations
numerous drug interactions
what are the side effects of methylxanthines
dysrhythmia seizures hypotension nausea vomiting abdominal discomfort headache
what are the 2 major classes of steroid hormone produced by adrenal cortex
glucocorticoid
mineralcorticoids
which class of steroid hormone produced fro adrenal gland is used in treatment of asthma
glucocorticoid
glucocorticoid increases/decreases inflammatory response
decreases
glucocorticoid increases/decreases immune response
decreases
glucocorticoid increases/decreases liver glycogen deposition
increases
glucocorticoid increases/decreases gluconeogenesis
increases
glucocorticoid increases/decreases glucose output from the liver
increases
glucocorticoid increases/decreases glucose utilisation
decreases
glucocorticoid increases/decreases protein catabolism
increases
glucocorticoid increases/decreases bone catabolism
increases
glucocorticoid increases/decreases gastric acid and pepsin secretion
increases
what are some examples of synthetic derivatives of cortisol
beclometasone
budesonide
fluticasone
why are glucocorticoids used in the prophylaxis of asthma
they have no direct bronchodilator effect when given acutely, hoover they can minimise adverse systemic effects
what type of nuclear receptor do glucocorticoids signal via
GRalalpha
are glucortcoids lipophilic or lipophobc
lipophilic
how do glucocorticoids enter the cell
diffuse across the plasma membrane
where do glucocorticoids combine with GRalpha
within the cytoplasm
what happens with glucocorticoid combine with GRalpha
produce dissociation of inhibitory heat shock proteins and activates the receptor
what do glucocorticoids do to genes when I the promoter region
transactivate (switch transcription on for anti-inflammatory genes)
trans-repressed (switch transcription off)
where do glucocorticoids act to regulate genes
glucocorticoid response elements (GREs)
where is the glucocorticoid response element
within the promotor region of specific genes
What do glucocorticoids do to TH2 cytokines
decrease their formation
induce apoptosis
How do glucocorticoids act on mast cells
reduce the number of cells and decrease Fce expression
How do glucocorticoids act on immunoglobulins
prevent IgE production
which inflammatory cells do glucocorticoids decrease
Eosinophil T-lymphocyte cytokines mast cells Macriphage cytokines Dendritic cells
Which structural cells do glucocorticoids affect
epithelial - decease cytokines and mediaors
Endothelial cells - leak
Airway smooth muscle - increase beta 2 receptors and decrease cytokines
mucus gland - decrease secretion
Common side effects of glucocorticoids
dysphonia
oropharyngeal candidiasis
Which steroid is used in chronic, severe or rapidly deteriorating asthma
oral prednisolone in combination with inhaled steroid
What is the action of cromones
they produce a weak anti-inflammatory effect
when are cromones used
prophylactically in treatment of atopic asthma
what is a specific cromone agent
sodium cromoglicate
what is an example of monoclonal antibodies against IgE
Omalizumab
how does Omalizumab work?
brinds to IgE via Fc t prevent attachment to FCe receptors on mast cells
what is an example of monoclonal antibody against IL5
mepolizumab
