Selective B2 agonists Flashcards
MoA
Causes bronchodilation of the bronchi
SABA
- 3-5 hours
- Salbutamol (QDS, PRN)
- Terbutaline (QDS - PRN)
LABA
- 12 hours
- Formoterol (BD)
- Salmeterol (BD)
Oral B2 agonist tablet
Bambuterol
When are LABAs used?
Patients regularly using ICS
Do not initiate in rapidly deteriorating asthma
Salmeterol
Long onset + long action
- Not for acute relief or prevention of exercise induced asthma
Formoterol
Short onset + Long action
- Can be used as reliever in addition to regular use as a preventer
- Review if using more than once a day
Brands
Beclometasone + Formeterol
- Fostair
- DuoResp Spiromax
- Symbicort (18+ years)
Side effects
- Hand tremors, tachycardia, hyperglycaemia
- Hypokalaemia
- CV effects
Hypokalaemia
Increased risk:
- Concomittant corticosteroids
- B2 agonists
- Theophylline
- Hypoxia in severe asthma
CV effects
QT prolongation
Arrythmias
Tachycardia
Arterial hypoxia = MI + hypotension.
CV - Caution in…
Hyperthyroidism
Label
Must explicitly state dose, frequency and max puffs in 24 hours.