Respiratory Drugs Flashcards
how does salbutamol work
beta 2 agonist
receptors found in smooth muscle of bronchi, GI tract, uterus and vessels
stimulation leads to relaxation
what relationship does salbutamol have with potassium
Drives K+ from extracellular to intracellular
used in treatment of hyperkalaemia + glucose and insulin
what must long acting beta 2 agonists be prescribed with
steroids, otherwise associated with increased asthma deaths
how does tiotropium bromide work? (Spiriva)
Anticholinergic
muscarinic receptor antagonist - brings about parasympathetic effects - causes bronchodilation and reduces mucus secretion
important contraindications of tiotropium bromide
patients susceptible to angle closure glaucoma - can cause rise in IOP
how does prednisolone work?
corticosteroid
anti-inflammatory effects - reduces prostaglandin and leukotriene synthesis
what are the possible side effects of prednisolone
increased risk and severity of infection muscle weakness, skin thinning, gastritis HTN, hypokalaemia, oedema suppresses ACTH secretion if withdrawn quickly - Addisonian crisis prolonged treatment >> adrenal atrophy
How does Carbocysteine work
mucolytic
reduces viscosity of sputum
contraindications of Carbocysteine?
pregnancy
active peptic ulceration
non-productive cough
how does theophylline work?
adenosine receptor antagonist (ATP)
reduces inflammation and innate immunity
relaxes airways in COPD patients
what extrapulmonary effects does theophylline have?
increases heart muscle contractility, rate, BP, renal blood flow
should theophylline be prescribed to an active smoker?
no, because of cardiac side effects
when is Oxygen therapy contraindicated?
Patients with chronic type 2 respiratory failure
respiratory drive is driven by chronic hypoxaemia
O2 can lead to respiratory acidosis
what are the various methods of delivery for Oxygen
Non-rebreather reservoir - 15L/min
Venturi mask - variable
Nasal cannulae - 2-6L/min
