Pharma 6 Flashcards
Short-acting β 2 -agonists fast onset
salbutamol, terbutaline)
salbutamol, terbutaline)
Use
- Used for symptom relief through reversal of bronchoconstriction
- Prevention of bronchoconstriction i.e. on exercise
- Short-acting β 2 -agonists should only be used on an as-required basis
- If used regularly, they reduce asthma control
Fast onset long duration
inhaled formoterol
slow onset, short duration
oral terbutaline oral salbutamol oral formoterol
Slow onset long duration
inhaled salmeterol
oral bambuterol
Regular preventer therapy in asthma
Inhaled corticosteroids
Beclomethasone
Ics ,,absorb through the gut&lung
Budesonide and fluticasone
Ics,, undergo extensive first-pass metabolism
Step 3
Add-on therapy for asthma
First choice – long-acting β 2 -agonists (formoterol, salmeterol)
Combined inhalers containing both an ICS and long-acting β 2 -agonist
- Budesonide/formoterol (Symbicort)
- Fluticasone/formoterol (Seretide)
- Beclomethasone/formoterol (Fostair)
Alternative step 3/step 4 add-ons
- High dose ICS
- Leukotriene receptor antagonists
- Theophylline
Leukotriene Receptor Antagonists
Montelukast, Zafirlukast)
LRAs block the effect of cysteinyl leukotreines in the airways at the CysLT1 receptor
Methylxanthines
(theophylline, aminophylline
- Antagonise adenosine receptors
- Inhibit phosphodiesterase – increase cAMP – unlikely to be relevant in vivo
- As with LTRAs, often poorly efficacious
- Narrow therapeutic window (10-20 mmol/L)
- Frequent side-effects – nausea, headache
- Potentially life-threatening toxic complications – arrhythmias, fits
- Important drug interactions – levels increased by cytochrome p450) inhibitors eg erythromycin, ciprofloxacin
Step 5
💥💥💥Use daily steroid tablet in the lowest dose providing adequate control
💥💥💥 maintain the highest dose of ICS
💥💥💥 Consider other treatments to minimize use of steroid tablets
• Oral steroids
• Step 5+, Anti-IgE
– Strict criteria for use, very expensive. Potentially reduces exacerbation rates in patients not controlled on oral steroids
Treatment of acute severe asthma
- Oxygen, high flow
- Nebulised salbutamol – continuous if necessary, oxygen driven
- Oral prednisolone ~40 mg daily for 10-14 days
- can be stopped without tailing down - If not responding, add nebulised ipratropium bromide
- Consider i.v. magnesium sulphate 1.2-2.0 g over 20 min
- Consider IV aminophylline if no improvement and life threatening features not responding to above treatment (BEWARE if taking oral theophylline ).