Pharmacology Flashcards
How do ‘relievers’ work?
act as bronchodilators
what drugs are classed as ‘relievers’?
- short acting Beta2-adrenoceptor agonists (SABAs)
- long acting beta2-adrenoceptor agonists (LABAs)
- cysLT1 (leukotrine) receptor antagonist
- methylxanthines
how do ‘controllers/prevents’ work?
act as anti- inflammatory agents that reduce airway inflammation
what drugs are classed as ‘preventers/relievers’?
glucocorticoids
cromoglicate
humanised monoclonal IgE antibodies
methylxanthines
How do beta2-adrenoceptor agonists work?
relax airway smooth muscle by inhibition of beta2 adrenoceptors and reduce intracellular Ca2+ concentration and activate large conductance potassium channels
what are examples of SABAs?
salbutamol aka albuterol
terbutaline
what is the first line treatment for mild, intermittent asthma?
SABAs
when are SABAs taken?
when needed
how are SABAs administered?
usually by inhalation, oral in children and IV in emergency
How long does it take for SABAs to start working?
often within 5 minutes, maximal effect within 30 minutes
how long does relaxation persist after using a SABA?
3-5 hours
what do SABAs do?
increase mucus clearance, decrease mediator release from mast cells and monocytes
what adverse effects may SABAs have?
fine tremor
tachycardia
cardiac dysrhythmia
hypokalaemia
what are examples of LABAs?
salmeterol and formoterol
How long do LABAs act for?
approx 8 hours
what must LABAs always be co-administered with?
glucocorticoids
what are examples of leukotriene receptor antagonists?
montelukast, zafirlukast
how do leukotriene receptor antagonists work?
act competitively at the cysLT1 receptor derived from mast cells and infiltrating inflammatory cells which cause smooth muscle contraction, mucus secretion and oedema
when are leukotriene receptor antagonists effective?
as add on therapy against early and late bronchospasm in mild persistent asthma and in combination with other medications, including inhaled corticosteroids in more severe conditions
what kind of bronchospams are leukotriene receptor antagonists effective against?
antigen-induced
exercise-induced
how are leukotriene receptor antagonists administered?
orally
what adverse effects have been reported for leukotriene receptor antagonists?
headache and GI upset
when are leukotriene receptor antagonists not recommended?
relief of acute severe asthma
what are methylxanthines present in?
coffee, tea and chocolate-containing beverages
what are examples of methylxanthines?
theophylline and aminophylline
what does theophylline do at high doses?
inhibits PDE3 potentiating the action of cAMP in ASM
what do methylxanthines do?
involve inhibition of isoforms of phosphodiesterases that inactivate cAMP and CGMP
what effects fo methylxanthines have?
combine bronchodilator and anti-inflammatory actions, inhibit mediator release from mast cells, increase mucus clearance, increase diaphragmatic contractility and reduce fatigue
when are methylxanthines used?
second line drugs used in combination with beta2-adrenoceptor agonists and glucocorticoids
what are some adverse effects of methylxanthines if administered at supra-therapeutic concentrations?
dysrhythmia
seizures
hypotension
what are some adverse effects of methylxanthines if administered at therapeutic concentrations?
nausea
vomiting
abdominal discomfort
headache
what are the two major classes of steroid hormone that are released into circulation?
glucocorticoids
mineralcorticoids
what does cortisol regulate?
decreases inflammatory responses decrease immunological responses increase liver glycogen deposition increase gluconeogenesis increase glucose output from liver decrease glucose utilisation increase protein catabolism increase bone catabolism increase gastric acid and pepsin secretion
what do mineralocorticoids (mainly aldosterone) do?
regulate the retention of salt (and water) by the kidney
what are examples of synthetic derivatives of cortisol?
beclometasone
budesonide
fluticasone
what are synthetic derivatives with little, or no mineralcorticoid activity, often used for?
their anti-inflammatory effect in the treatment of asthma
what are glucocorticoids ineffective in?
relieving bronchospasm as they have no direct bronchodilator action.
how are glucocorticoids administered?
preferably by the inhalation route to minimise adverse systemic effects
why are glucocorticoids given in asthma?
for prophylaxis, they prevent inflammation
what are the adverse effects of glucocorticoids?
dysphonia (weak/hoarse voice) oropharyngeal candiadias (thrush)
what may be given in severe, rapidly deteriorating asthma?
oral prednisolone in combination with an inhaled steroid to reduce oral dose required and minimise unwanted systemic effects. bronchodilator drugs are co-administered
when are cromones used?
second line drugs infrequently used in the prophylaxis of allergic asthma (particularly in children)
what is an example of a cromone?
sodium cromoglicate
how is sodium cromoglicate administered?
inhalation
who is sodium cromoglicate more effective in?
children and young adults
what does SAMA stand for?
short acting muscarinic antagonist
what does LAMA stand for?
long acting muscarinic antagonist
what are examples of SAMAs?
ipratropium
what are examples of LAMAs?
tiotropium
glycopyrronium
aclidinium
umeclidinium
how are SAMAs and LAMAs administered?
by inhalation
how do SAMA/LAMA work?
reduce bronchospasm caused by irritant stimuli and also block ACh-mediated basal tone, decrease mucus secretion
what is ipratropium a non-selective blocker for?
M1,M2,M3 receptors
what will glucocorticoids do over several weeks in the treatment of rhinits?
reduce all symptoms, including nasal congestion
what might glucocorticoids be combined with in moderate-to-severe rhinitis?
anti-histamines
what are examples of glucocorticoids given for rhinitis?
beclometasone
fluticasone
prednisolone
what do anti-histamines do?
competitive antagonists that reduce effects of mast cells derived histamine including vasodilatation and increased capillary permeability, activation of sensory nerves and mucus secretion from submucosal glands
how are anti-histamines administered?
orally or an intranasal spray (azelastine)
what are examples of anti-histamines?
loratidine
fexofenadine
cetirizine
what drugs can be used in treatment of rhinitis?
glucocorticoids anti-histamines leukotriene receptor antagonists muscarinic receptor antagonists sodium cromoglicate vasoconstrictors
what is the mechanism of action of vasoconstrictors?
act as directly, or indirectly, to mimic the effect of noradrenaline. produce vasoconstricton via activation of alpha1-adrenoceptors to decrease swelling in vascular mucosa
what is an example of a vasoconstrictor?
oxymetazoline
