Respiratory Pharmacology 2 Flashcards
State examples of inhaled corticosteroids?
Beclometasone Budesonide Ciclesonide Fluticasone propionate Fluticasone furoate Mometasone furoate
Adverse effects of corticosteroids?
SO MANY.
Sleep disturbance, psychosis, acne, oedema, intracranial hypertension, Diabetes mellitus, osteoporosis, cataracts, growth retardation
Difference between Cushing’s disease and Cushing’s syndrome?
Cushings disease: caused by a tumour on pituitary gland, PG produces too much ACTH. ACTH responsible for cortisol production.
Cushing’s syndrome: due to causes outside body increasing levels of cortisol
- e.g. taking corticosteroids
How do long acting beta 2 agonists work for longer?
- Long tail and lipid soluble benzene ring.
- Tail end in lipid membrane
- anchored in membrane
- hence hangs around receptor for longer.
Describe the BTS guidelines towards giving LABA?
LABA 1st choice add-on therapy to inhaled corticosteroids.
Considered before increasing dose of inhaled corticosteroids.
Why should LABAs be given only as an add-on?
- Chronic exposure to LABAs can be associated with tolerance
- and reduced sensitivity to bronchodilator effects of salbutamol.
- More people die on LABA monotherapy than as add on therapy.
Describe the relatively new medication Vilanterol and its perks?
Main difference is that other LABAs have to be taken twice a day. However vilanterol can be taken once a day, may improve patient adherence to medication
Fostair inhaler
Combination of beclomethasone diproprionate and formoterol fumarate
Duoresp
Symbicort
Budesonide and formoterol fumarate
Relvar
Fluticasone furoate and vilanterol
AirFluSal
Seretide
Fluticasone propionate
Salmeterol
- Most people are on Seretide
Examples of leukotriene receptor antagonists
Montelukaust
- v.tasty tablet
Zafirlukast
Pranlukast (not licensed in UK)
Arachidonic acid
Major constituent of cell membrane phospholipids.
Leukotrienes
Potent bronchial smooth muscle constrictors.
- Leukotrienes C4 & D4 approx. 1000x more potent than histamine.
Formation of leukotrienes through which pathway depends on the lipoxygenation of arachidonic acid?
5-lipoxygenase pathway
Describe some side effects of taking Montelukast neuropsychiatric ADRs
Sleep disturbances, depression and agitation.
Disturbances of attention or memory.
Hallucinations
Suicidal behaviour
What is the difference between aminophylline and theophylline?
Aminophylline: drug combo of theophylline and ethylenediamine in a 2:1 ratio.
Aminophylline may be administrated via
ONLY GIVEN AS IV.
Theophylline may be administered
Orally.
Used in oral version,
Describe jist of the action of theophylline
Relaxes smooth muscle of bronchial airways, pulmonary BV and reduces airway responsiveness to histamine, methacholine, adenosine and allergen.
Describe mechanism of action of theophylline?
Competitively inhibits type III and type IV phosphodiesterase.
- enzyme responsible for breaking down cAMP in smooth muscle cells
Also binds to the adenosine A2B receptor and blocks adenosine mediated bronchochonstriction.
Describe action of theophylline in inflammatory states?
- Activates histone deacetylase to prevent transcription of inflammatory genes that require the acetylation of histones for transcription.
Describe the toxicity of theophylline?
Very toxic.
Requires therapeutic drug monitoring to ensure high levels are avoided.
Theophylline overdose can cause…
Vomiting, agitation, restlessness, dilated pupils, sinus tachycardia, and hyperglycaemia
More serious:
- haematemesis
- convulsions
- supraventricular and ventricular arrhythmia’s
What are some biologic therapies?
Omalizumab
- anti-IgE monoclonal antibody
- subcutaneous inj every two or four weeks, depending on IgE level and weight,
Mepolizumab, Reslizumab and benralizumab
- Anti-IL-5 monoclonal antibody
Describe when omalizumab may be given?
Via subcutaneous injection
- for patients with convincing IgE mediated asthma.
- may take 12-16 weeks to show effectiveness
What are complementary determining regions CDRs?
Part of variable chains in immunoglobulins and T cell receptors.
How does Omalizumab work?
- Humanized mAb against IgE
- Binds circulating IgE regardless of specificity
- Forms small, biologically inert Omalizumab: IgE complexes
- Does not activate complement
Omalizumab works by
- Binding to free IgE
- Decreases cell bound IgE
- Decreases expression of high affinity receptors
- Decreases mediator release
- Decreases allergic inflammation
- Prevents exacerbation of asthma and reduces symptoms.
How does mepolizumab work?
Meopolizumab binds with high affinity to IL-5, thus preventing its interaction with the IL-5 receptor expressed by eosinophils and to a lesser extent basophils.
