Respiratory Flashcards
How does salbutamol work ?
Stimulate B2 receptors in airways (sympathetic stimulation) promoting bronchodilation
- also inhibits uterine smooth muscle contraction in premature labour
Indictations for salbutamol
- asthma
- chronic bronchitis
- Premature labour
- severe bronchospasm
Contraindications and cautions of salbutamol
- Tachyarrhythmias
- hypersensitivity
Caution in:
- CV disease
- hyperthyroidism
- long QT
- diabetes
What are the side effects of beta 2 agonists?
- fine tremor (usually in hands)
- nervous tension
- headache
- muscle cramps
- palpitations
- Hypokalaemia (rare)
What is the main route of elimination of salbutamol ?
Hepatic
Under what conditions is salbutamol more likely to cause hypokalaemia ?
If delivered by nebuliser or parenterally
What drug class is ipratropium bromide ?
Anticholinergic, antimuscarinic bronchodilator
Indications for ipratropium bromide
- reversible airways obstruction
- COPD
- rhinitis
How does ipratropium bromide work ?
- Inhibit parasympathetic impulses (from CNS and PNS) by competitively blocking acetylcholine therefore preventing contraction of smooth muscle (specifically lungs)
- also inhibits muscarinic ACh receptors, inhibiting mucous secretion in the bronchi
In which patients should antimuscarinics be used with caution ?
- benign prostatic hyperplasia
- bladder outflow obstruction
- those at risk of closed angle glaucoma
What are the side effects of antimuscarinic bronchodilators ?
- dry mouth (most common)
- nausea
- headache
What are the possible interactions of ipratropium bromide ?
- Clarithromycin and erythromycin
- Increased side effects with antidepressants
What class of drug is prednisolone ?
Corticosteroid
How does prednisolone work ?
- Inhibits Phospholipase A2 activity = decreased arachidonic acid production (precursor for prostaglandin and leukotriene synthesis)
- therefore less inflammatory mediators produced= anti inflammatory effect
- immunosupressive effect (decreased B and T lymphocyte response)
Indications for prednisolone:
Suppression of inflammatory and allergic disorders:
- IBD
- asthma
- croup
- immunosupression (leukaemia, transplant)
- rheumatic diseases
Contraindications of prednisolone
- adrenal suppression
- systemic infection
- osteoporosis
Side effects of corticosteroids
- more susceptible to infections (severe with atypical presentation)
- bruising
- hirsutism (abn. Female hair growth)
- moon face
Interactions of prednisolone
Phenytoin and rifampicin cause decreased effects of prednisolone
Elimination of prednisolone
Renal
Why can’t prednisolone treatment be stopped abruptly ?
Adrenal crisis
What drug class is oxygen ?
Therapeutic gas
Indications for oxygen therapy?
- resuscitation (100%)
- acute hypoxic events e.g. MI, asthma, PE, sepsis (60%)
- risk of hypercapnic respiratory failure e.g. COPD
What oxygen saturation should be aimed for in those at risk of hypercapnic respiratory failure (COPD) ?
88-92%
Which drug is in the brown inhaler (disease controller)?
Inhaled corticosteroid e.g. Beclometasone , budesonide, fluticasone
Other than inhaled corticosteroids which other disease modifying drugs can be used ?
Leukotriene modifiers - prevents wheezing and shortness of breath in asthma by blocking release of leukotrienes from mast cells, basophils and eosinophils which normally cause constriction and increased mucus production
What drug class is salbutamol ?
Short acting Beta-2 agonist
