Resp drugs Flashcards
Stepwise dosing of asthma meds?
1) SABA PRN
2) Add low dose ICS (alternative motelucast or cromolyn)
3) Increase to Medium dose ICS
4) Add Laba or Montelukast
5) High dose ICS and LABA or Montelukasr
6) add oral corticosteroids
short acting beta 2 agonist? Long acting one?
how does it work?
side effects? avoid in which patients?
interactions?
agonists – Short acting: Salbutamol, Long acting: salmeterol
B2 receptor activation indirectly causes smooth muscle relaxation (in the bronchi, GI, uterus and blood vessels) bronchodilation improves air flow. Can help treat hyperkalaemia.
Causes tachycardia (Try and avoid in patients w/ CVD as can cause angina/ arrhythmia), can also get palpitations, tremor, anxiety. May increase glucose. Long acting may cause muscle cramps.
B blockers reduce effectiveness (and trigger attacks). High dose B2-agonists + theophylline + corticosteroid cause hypokalaemia (check U&Es)
Tiotropium, Ipatropium are both what? they do what? how?
used in?
Cautions?
short acting bronchodilatory anti-muscarinic:
Anti-muscarinincs compete with acetylcholine to competively inhibit muscarinic Rs preventing parasympathetic response. They have the opposite response increasing HR and conduction – decreasing: smooth muscle tone, contraction and secretions in the gut, urinary tract and respiratory system. In the eye they dilate and prevent accommodation.
Used in COPD: Short acting - Used to relieve breathlessness & exacerbations. LAMAs – used to prevent breathlessness and exacerbations.
Asthma: as an adjuvant (w/B2 agonists) to relieve breathlessness in acute exacerbations. Long acting + ICS = step 4 chronic asthma.
Caution: can precipitate closed angle glaucoma.
- Little systemic absorption or side effects (dry mouth – water, gum), caution in patients w/ arrythmia
- Like B2 agonists treating the symptoms not the cause.
Name an ICS
What is the mechanism of action?
used in?
SE?
Watch for side effects in which patient group?
Inhaled – Beclomethasone
Corticosteroids pass cause downregulation of pro-inflammatory interleukins, cytokines and chemokines while anti-inflammatory proteins are upregulated. In the airways this reduces mucosal inflammation, widens the airway and reduces mucus secretion. (reduces inflammation in the lung)
- Used in Asthma: To prevent symptoms, to treat inflammation (step 2)
- Used in COPD: To control symptoms and prevent exacerbations + B2 agonist/LAMA
SEs: Unlikely to be systemic effects e.g. weight gain, growth retardation (avoid high dose e.g. fluticasone in children) as limited to local airway – immunosuppression= oral candidiasis & hoarse voice in COPD (rinse their mouth and gargle after)
Use in caution in COPD patients with history of pneumonia as may increase risk.
Systemic (IV, PO, IM) – Prednisolone
To treat allergy/inflammatory disorders – anaphylaxis, asthma
* Suppression of autoimmune disease – IBD, inflammatory arthritis
* To treat cancer and hormone replacement – adrenal insufficiency/hypopituitarism
Side effects?
Interactions?
When to take? other advice to pt?
SEs: Immunosuppression (infection). Metabolic (DM, osteoporosis, skin thinning). Mood and behavioural changes (insomnia, confusion, psychosis, suicide ideation). Mineralocorticoid (HTN, hypokalaemia, oedema). Suppresses ACTH if withdrawn suddenly can cause adrenal atrophy and Addison’s crisis. Can suppress children’s growth.
Interactions: NSAIDs (Increase risk of peptic ulcer). Efficacy reduced by cyt P450 inducers. B2 agonist + theophylline - combination can casue hypokalaemia.
Take daily in morning to mimic natural circardian rhythm (reduce insomnia) asthma take 40 mg orally daily – will feel better w/in 1-2 days, in prolonged treatment do not suddenly stop.
Carbocysteine - what is it? how does it work? SE>?
Mucolytic -
* Facillitates expectoration by reducing sputum viscocity, may also prevent chest infection
Use: COPD, chronic productive cough to reduce exacerbations – stop after 4 weeks if no clear benefit. (Steam inhalation – bronchiectasis, chronic bronchitis)
* SEs: peptic ulcer (avoid if they have one), rarely GI bleed, Steven-Johnson syndrome, erythema multiforme
Theophylline - used when?
Used for? how does it work?
Cautions and SE’s
Used in severe acute asthma (asthma/stable COPD)
Bronchodilator, relaxes smooth muscle in airways, decreases response to irritants and improves diaphragm contraction. Eliminated via liver – a xanthine inhibits PDE & decreases inflamm.
Caution: cardiac arrhythmias, CVD, HTN. Peptic ulcer, epilepsy, elderly, hypokalaemia (B2 agonist)
* SEs: GI: Nausea, vomiting, diarrhoea. Heart: Palpitations, tachycardia, arrhythmia. CNS: Headache, insomnia, convulsions.
02 Contraindications?
Contraindications: Type 2 respiratory failure – COPD – hypoxic drive
