Respiratory Drugs Flashcards
What are SABAs and LABAs
Short acting beta agonists
Long acting beta agonists
What are the main indications of SABA or LABAs?
- Asthma
- COPD
- Hyperkalaemia (nebulised)
Give some examples of SABAs?
Salbutamol and Terbutaline
Give some examples of LABAs?
Salametrol and Formoterol
What is the MOA of the Beta agonists in treating breathlessness?
This drug activates the beta 2 receptors found in the smooth muscle of the bronchi, gut, uterus, blood vessels.
this activation will stimulate the GPCR signalling cascade, this in turn causes smooth muscle relaxation.
This improves airflow in constricted airways to reduce the symptoms of breathlessness.
What is the MOA of beta agonists in the treatment of Hyperkalaemia?
This drug stimulates Na/K ATPase pumps causing K+ to move from outside to inside of the cells.
Useful in treatment of hyperkalaemia, esp when IV access is difficult; should not be used in isolation
What are the side effects of beta agonists?
Common:
- Palpitations
- Tachycardia
- Anxiety
- Tremor
Promote glycogenolysis which increases serum glucose concenctration.
At high doses, serum lactate levels may rise
LABAs can cause muscle cramps
Whom are beta agonists contraindicated in?
LABAs MUST BE GIVEN WITH AN ICS in asthma
CAUTION in patients with cardiovascular disease
- Tachycardia may provoke angina/ arrhythmias
What are the key interactions of beta agonists?
Effectiveness may be reduced by BETA-BLOCKERS
Concomitant use of high-dose nebulised beta2-agonists with THEOPHYLLINE and COTICOSTEROIDS can cause hypokalemia so serum K conc should be monitored
Give examples of ICS and what it stands for:
Inhaled corticosteroids
Clenil
Budesonide
What are the main indications of ICS?
Asthma and COPD
What is the MOA of ICS?
Pass through the plasma membrane to interact with receptors in cytoplasm.
Activated receptor passes into the nucleus to downregulates pro-inflammatory interleukins, cytokines and chemokinesAND upregulates anti-inflammatory proteins.
In the airways ICS reduce the mucosal inflammationto Widens the airwaysAND reduces mucus secretionwhich Improves symptoms and reduces exacerbations in asthma and COPD.
What are the main side effects of ICS?
Locally:
- Oral candidiasis
- Hoarse voice
- increase rick of pneumonia in COPD
Very little is absorbed into blood so few systemic adverse effects - unless taken at very high dose in which can experience:
- Adrenal suppression
- Growth retardation
- Osteoporosis
Whom are ICS contraindicated in?
High-dose ICS, esp fluticasone, used with caution in:
- COPD pts with a history of pneumonia
- Children, where there is potential for growth suppression
What are the main indications of Theophylline?
- Reversible airway obstruction
- Severe acute asthma
- Chronic asthma
- COPD
What is the MOA of Theophylline?
Non-selectively inhibits phosphodiesterase which breaks down cAMP.
Directly stimulates the respiratory centre to increase respiration
Inhibits adenosine A1 and A2 receptors.
What are the main side effects of Theophylline?
- Anxiety
-Arrhythmias - Diarrhoea
- Dizziness
-GI discomfort - GORD
- Headache
- Palpitations
- Seizure
- Skin reactions
- Sleep disorders
- Tremor
- Urinary disorders
Whom is Theophylline contraindicated in?
Cautions:
- CARDIAC ARRHYTHMIAS
- Elderly
- Epilepsy
- Fever
- HTN
- Peptic ulcer
- Risk of HYPOKALAEMIA
- Thyroid disorder
- In adults, prescription potentially inappropriate (STOPP criteria) as monotherapy for COPD (safer and more effective alternatives available; risk of adverse effects due to narrow therapeutic index)