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Pharmacy Year 2 Semester 2 > Asthma > Flashcards

Flashcards in Asthma Deck (54)
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1
Q

Triggers

A
  • cold air
  • dust mites
  • pollen/animal fur/dust mites
  • smoke/fumes/pollution
  • NSAIDs
  • emotion e.g. stress/laughter
2
Q

Pathology of asthma

A

immune condition mediated by IgE
IgE formed in response to a trigger.
Re-exposure to the allergen casues this specific IgE on mast cells, causing an inflammatory response:
-Histamine, prostaglandins, leukotrienes and eosinophils infiltrate the airway
-goblet cells over-produce mucous
-T lymphocytes produce cytokines that potentiates the inflammatory response
-This cascade causes bronchospasm - hyper-responsive smooth muscle on airway to narrow

3
Q

Diagnosis of asthma

A
  • No single test can diagnose asthma
  • Combination of history, examination, tests to access the probability of asthma
  • Diagnosis is through lung function testing and reversibility tests with either a SABA or an corticosteroid
4
Q

Lung function tests to help diagnose asthma

A

-FVC
-FEV1
-FEV1:FVC ratio
-PEFR
FeNo

5
Q

Define FVC

A

Forced vital capacity

Total volume expelled by the lungs

6
Q

Define FEV1

A

Forced expiratory volume exhaled in first second of FVC

7
Q

FEV1:FVC ratio normal values

improvement?

A

Normal 0.7
Below this indicates obstruction
Obstruction is reversible in asthmatic patients whom should see an increase of 400ml to lung capacity after taking salbutamol

8
Q

PEFR

A

Peak expiratory flow rate
Done via peak flow meter
Maximum rate of airflow which can be achieved during a sudden forced expiration from a position of full inspiration

9
Q

What do you do with the spirometry results?

A

Compare against predicted values for those patients that took it
Based on: age, height, race and sex

10
Q

Uncontrolled asthma has what spirometry test results?

What happens after administration of salbuatmol?

A

Decrease if PEF and FEV1 in uncontrolled asthma

400mL increase in lung capacity after salbutamol administration

11
Q

FeNO

A

Functional exhaled nitric oxide
indicates airway inflammation
elevated levels in asthma patients

12
Q

Other non-spirometry tests

A

Blood eosinophils - inflammation
allergies
IgE levels

13
Q

Presentation of asthma

A

wheezing
shortness of breath (dysponea
coughing - particularly at night and on waking
triggers from allergens
if severe - cyanosis, drowsiness, difficulty speaking full sentences

14
Q

aims of asthma treatment

A
  • control symptoms, including nocturnal and exercise-induced exacerbations
  • Reduce reliance on rescue therapy
  • Prevent exacerbations
  • Achieve best possible lung function: FEV1 and/or PEF >80% predicted or best
  • minimising side effects of medication
15
Q

“Control” of asthma is defined as

A
  • no daytime symptoms
  • no nighttime symptoms
  • no need for rescue medication
  • no limitations on activity, including exercise
  • no exacerbations
  • normal lung function: FEV1 and/or PEF >80% predicted or best
  • minimal side effects of treatment
16
Q

Non-pharmacological management of asthma

A
  • Avoiding triggers
  • stop smoking
  • lose weight if obese
  • avoid exercise in cold air
  • minimise occupational stimuli
  • avoid NSAIDs and Beta-blockers (including eye drops)
  • Hollistic remedies (immunotherapy, Buteytco breathing technique)
  • Breast feeding
  • -air ionisers
17
Q

Treatment of chronic ashtma

A
  • inhaled (with spacer/nebuliser) and oral routes of administration
  • this makes side effects and ADRs more common due to the route being more systemic
18
Q

Reliever

A

SABA e.g. salbutamol
produces quick symptomatic relief
Normally PRN

19
Q

Preventer

A

Corticosteroids i.e. beclomethasone
Act on underlying inflammation
Usually PRN

20
Q

Controller

A

:LABA e.g. salmeterol

Slow onset, long-acting, usually BD

21
Q

Nebulisers

A

Vaporise aqueous solution of drug (normally salbutamol or ipratropium) to mist for inhalation through a mask or mouthpiece
They offer high dose delivery and are particularly useful in acte or chronic/severe asthma as
co-ordination not needed
Often used in hospitals

22
Q

B2-agonists

A

Caause smooth muscle relaxation and enhance mucociliary clearance

  • SABA
  • LABA
  • 3rd line controllers
23
Q

SABAs
2 examples
onset and duration

A

Salbutamol and terbutaline
Onset 1-5minutes
Duration 4-6 hours
1st line relievers offer quick symptomatic relief

24
Q

LABAs
2 examples
onset and duration

A

Salmeterol

  • onset 10-20 minutes
  • duration 12hours

Formoterol
-onset 1-3 minutes
duration 12 hours

25
Q

B2 agonists ADRS

A
  • fine tremor
  • nervous tension
  • headache
  • peripheral vasodilation
  • tachycardia
  • hypokalaemia
26
Q

Corticosteroids

A

2nd line preventers

Anti-inflammatory reducing bronchial hyper-response

27
Q

ICS

3 examples

A
Inhaled corticosteroids 
Beclomethasone
Budesonide
Ciclesonide
Available in combination with LABA 
ICS are classed as either low, medium or high doses
28
Q

Oral corticosteroids

A

Prenisolone
Usually 40-50mg for 5 days for acute attacks
40-50mg =minimum effective dose in step 5

29
Q

IV corticosteroid

A

Hydrocortisone
used in acute severe situations
suppresses inflammatory processes

30
Q

When are corticosteroids indicated?

A
  • exacerbation of asthma in last 2 years
  • using inhaled B2 agnoist >3times/week
  • symptomatic >3times/week
  • waking one night a week due to symptoms
31
Q

Inahled corticocosteroid ADRs

and solutions

A

-hoarseness or dysphonia (difficulty speaking)
if this happens, use spacer/dry powder

  • oral candidiasis -rinse mouth after use or use spacer
  • adrenal suppression - only in sustained doses >1500mcg Beclomethasone daily
32
Q

Oral corticosteroid ADRs

A

-hypertension
-osteoporosis
-skin thinning
-hyperglycaemia
-adrenal suppression
-moon face
-acne
which is why for oral corticosteroids, we use the lowest dose that will control symptoms for the shortest time possible

33
Q

Leukotriene antagonists

examples

A
  • 3rd/4th line controller/preventer
  • oral montelukast and zafirlukast
  • antagonise bronchoconstriction, airway oedema and mucous production
34
Q

ADRs for leukotriene antagonists

A
  • abdominal pain
  • headache
  • thirst
  • rash
  • sleep disturbances/CNS effects
35
Q

Cromones

A

Necocromil - preventer in 5-12 year olds

-mast cell stabilisers, inhibits mediator (histamine) release from mast cells

36
Q

Cromones ADRs

A
  • nausea and vomiting
  • bitter taste
  • dispepsia
37
Q

Immunosuppressants

A

-Methotrexate
-ciclosporin
-gold
specialist use - used rarely

38
Q

Methylxanthines - how they work

A

Think INTERACTIONS and ADRs!
phosphodiesterase inhibitors that inhibit leukotriene synthesis and therefore inhibit inflammation and bronchoconstriction
3rd/4th line controller/preventer therapy

39
Q

Methylxanthine examples

A
  • oral: theophylline
  • IV/oral - aminophylline (salt of theophylline)
  • Narrow therapeutic index
  • SR preparations available to give predictable effect
  • Brand MUST remain constant
40
Q

Therapeutic range for methylxanthines

A

10-20mg/L

41
Q

Side effects of methylxanthines dependent on plasma concentrations

A
  • <20mg/L - nausea, diarrhoea, nervousness, headache
  • > 20mg/L vomiting, insomnia, arrhythmias
  • > 35mg/L - hyperglycaemi, arrhythmias, convulsions, death
42
Q

Methylxanthine clearance affected by

A

CYP450 metabolism

  • CCF (congestive heart failure)
  • liver disease
  • obesity
43
Q

How to work out methylxanthine dose

A

by IBW (ideal body weight)

44
Q

Methylxanthine interactions

A

1) enzyme inhibitors - these interactions can lead to toxicity
e. g.
- cimetidine
- erythromycin
- allopurinol
- ciprofloxacin

2) enzyme induction - these interactions can lead to sub-therapeutic doses
e. g.
- carbamazepine
- rifampicin
- phenytoin
- smoking
- alcohol

45
Q

Anti IgE monoclonal antibodies

A

-Omalizumab
inhibits binding of IgE to mast cell receptors, therefore preventing inflammatory response to triggers
-licensed as add-on therapy in adults and children>12yrs for severe, persistent asthma
-S/C injection every 2-4 weeks
-only initiated by specialist centres
-patients must fulfil specific NICE criteria
-discontinue after 16 weeks if inadequate response (4-8 injections)

46
Q

Outline the BTS/SIGN guidelines for adult management of acute+severe asthma

A

Patients should be reviewed every 3-6 months with a view of stepping down treatment
Steps
If asthma suspected, give SABA PRN
1) Monitored initiation of low dose ICS

2) Add LABA (LABA+low dose ICS as combo inhaler)

3)Additional add on therapies
-No response to LABA→stop LABA, consider ↑ICS dose
-Benefit from LABA but control still bad→continue LABA, ↑ICS to medium dose OR Continue LABA and ICS and consider a trial of a LTRA, SR Theophylline or LAMA

4) High dose therapies
Refer to specialist care
Consider trials of:
-↑ICS up to high dose
-Adding on a 4th drug e.g. LTRA, SR theophylline, B2-agonist tablet, LAMA

5) Continuous or frequent use of oral steroids
-refer to specialist care
-use daily steroid tablet in the lowest dose providing adequate control
-Maintain high dose ICS
-consider other treatments to minimise use of steroid
tablets

NB- SABA PRN is on ALL steps

47
Q

Outline the management of chronic and acute asthma in children

A

Asthma suspected - consider very low dose→low dose ICS
1) Infrequent, short-lived wheeze. Asthma diagnosed
Regular preventer - very low (paediatric) dose ICS or LTRA <5 years

2) continue v.low dose ICS plus
-children > or equal to 5yrs - add inhaled LABA
-children<5yrs- add LTRA

3) Additional add-on therapies:
-no response to LABA→stop LABA and increase dose of ICS to low dose
-if benefit from LABA but still inadequate control, continue LABA and ↑ICS to low dose
-If benefit from LABA but control still inadequate, continue LABA and consider trial of a LTRA

4) High dose therapies
-refer patient to specialist care
consider trials of:
-↑ICS to medium dose
-Addition of a 4th drug - SR theophylline

5) Continuous or frequent use of inhaled steroids
-refer to specialist care
-use daily steroid tablet in the lowest dose providing adequate control
-maintain medium dose ICS
-consider use of other treatments to minimise use of steroid tablets

48
Q

General advice for acute asthma in adults

A
  • do not underestimate risk of death
  • emergency admissions are avoidable
  • patients who die have well-recognised risk factors which can be modified
  • PEF<50% - severe
  • PEF <33% - life-threatening
  • RR>25/min
  • HR>110/min
  • O2 saturation <92%
49
Q

Severe/life threatening exacerbations present with what symptoms?

A
  • cyanosis
  • difficulty speaking
  • unconciousness
  • tachycardia
  • severe dysponea
50
Q

If an asthma patient requires hospitalisation due to an asthma attack, what do you do?

A

immediate prescription

  • oxygen at highest possible concentration 40-60% aiming for arterial oxygen saturation of 94-98%
  • B2-agonist nebulised - 5mg QDS or multiple doses (2-10 puffs of sabutamol 100mcg at 10-20 minute intervals via spacer, depending on severity)
  • corticosteroid: prednisolone 40-50mg oral at least 5 days OR IV hydrocortisone every 6 hours (hold ICS)
  • Consider:
  • Ipratropium nebules 500mcg 4-6 hourly
  • single dose IV magnesium sulphate if PEF<50%
  • IV theophylline/IV salbutamol
51
Q

Magnesium sulphate

A

smooth muscle relaxant, T cell and mast cell stabiliser

52
Q

Monitoring requirements if you’ve just admitted someone having an asthma attack

A
  • PEF
  • O2 saturation (aim 94-98%)
  • arterial blood gases
  • HR/RR - tachycardia/ponea
  • CRP
  • WCC if infection is suspected
  • Theophylline levels (if continued >24h)
  • serum K+ (nebulised SABA)
  • glucose
  • hydration
  • Blood pH~7.4 (check for risk of acidosis)
53
Q

When do you refer an asthma patient who is having an asthma attack to ITU?

A
  • deteriorating PEF
  • persistent hypoxia
  • exhaustion, drowsiness
  • coma, respiratory arrest
54
Q

During hospitalisation, after attack is dealt with

A
  • IV→nebuliser→inhaler
  • oral steroid 40mg/50mg for 5 days at least, depending on severity
  • restart steroid inhaler
  • write and meet discharge criteria
  • make action plan
  • inhaler technique education