Flashcards in Pharmacology 2 - Asthma (2) Deck (100)
What are the 2 main categories of drugs that are used to treat asthma?
What do relievers act as?What do controllers/ preventers act as?
BronchodilatorsAnti-inflammatory agents that reduce airway inflammation
What are the possible types of reliever medication for asthmatics? (3)
Short acting B2-adrenoceptor agonists (SABAs)Long acting B2-adrenoceptor agonists (LABAs)CysLT1 receptor antagonists
What are the possible types of controllers/ preventers available for asthma?(3)
GlucocorticoidsCromoglicateHumanised monoclonal IgE antibodies
What drug acts as both a bronchodilator and anti-inflammatory drug?
What is step 1 of the guideline approach for treating asthma?
If it is very intermittent asthma then prescribe a SABA
What is step 2 of the guideline approach for treating asthma?
If SABA is needed more than once a day, add a regular, inhaled glucocorticoid (Inhaled corticosteroid, ICS)
What is step 3 of the guideline approach for treating asthma?
If control is inadequate, add a long-acting B2-adrenoceptor agonists (LABA)monitor benefit and if good continue LABAIf of benefit but not adequate, increase dose of icsif no response, stop LABA and increase dose of ICSIf control is still inadequate, trial other therapy (e.g. cysLT1 receptor agonist or theophylline)
What is step 4 of the guidelines approach for treating asthma?
If asthma is persistent and poorly controlled, increase dose of ICS. Add a fourth drug (e.g. Cyslt1 receptor antagonist, theophylline, oral b2 agonist)
What is step 5 of the guideline approach to treating asthma?
If control is still inadequate, introduce oral glucocorticoid - refer patient to specialist care
Comparison of the pharmacokinetics of aerosol and oral therapy for asthma?
Aerosal = slow absorption from lung surface and rapid systemic clearanceOral = good absorption (with exceptions) and slow systemic clearance
Comparison of the dose of aerosol and oral therapy for asthma?
Aerosal = low dose delivered rapidly to targetOral = high systemic dose necessary to achieve an appropriate concentration in the lung
Comparison of the systemic concentration of the drug between aerosol and oral therapy for asthma?
Aerosol = lowOral = high
Comparison of the incidence of adverse effects between aerosol or oral therapy for asthma?
Aerosol = low incidence of adverse effectsOral = high (but depends on drug)
Comparison of the distribution of the drug between aerosol and oral therapy for asthma?
Aerosol = reduced distribution in severe airway diseaseOral = unaffected distribution by airway disease
Comparison between compliance with aerosol and oral treatment?
Aerosol = good with bronchodilators, less so with anti-inflammatory drugsOral = good
Comparison between ease of administration of aerosol and oral drugs for asthma?
Aerosol = difficult for small children and infirm peopleOral = good
Comparison between effectiveness of aerosol and oral drugs for asthma?
Aerosol = good in mild to moderate diseaseOral = good even in severe disease
What is a spasmogen?
A substance causing contraction of smooth muscle e.g. histamine
What does binding of an agonist to a B2-adrenoceptor cause?
Binding of the agonist causes the B2-adrenoceptor to activate GS increasing the activity of adenylyl cyclase Adenylyl cyclase converts ATP to cAMP which binds to Protein kinase A (PKA) activating itPKA phophorylates MLCK (inhabiting it) and myosin phosphatase (activating it)This causes relaxation of the bronchial smooth muscle = bronchodilation(this therefore opposes the action anything that causes constriction of airway smooth muscle)
What are the classifications of B2-adrenoceptor agonists? (3)
Short-acting (SABA)Long-acting (LABA)Ultra long acting
What is an example of a short acting B2-adrenoceptor agonist?What are 3 other names for this?
What is the first line treatment for mild, intermittent, asthma?
What are some examples of ways that SABAs are administered?
Usually inhalation (metered dose/ dry powder devices)Oral is sometimes used in childrenIV is given as an emergency sometimes
How quickly do SABAs act?When do they have their maximal effect?How long does relaxation persist for?
5 minutes for onset30 minutes = peaksRelaxation persists for 3-5 hours
What effect do SABAs have?
They increase mucus clearance and decrease mediator release from mast cells and monocytes
What are some side effects that can occur with SABAs when given via the inhalation route? (4)
Fine tremorTachycardiaCardiac dysryhtmiahypokalaemia
Why can the drug sometimes affect the heart?
B1 adrenoceptors are on the heart
What causes the B2-agonist tremor?
Skeletal muscles sometimes carry B2-adrenoceptors