Pharmacology - Respiratory Pharmacology Flashcards

1
Q

Asthma

A
  • Reversible bronchonconstriction and inflammation

- Decrease in FEV1 <70% –> Increase in airway resistance

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2
Q

COPD

A
  • not fully reversible
  • chronic bronchitis and emphysema
  • loss of lung function
  • mostly caused by smoking
  • typically late onset
  • high energy demand and difficulty eating –> use inhalers before meal
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3
Q

COPD Severity

A

Mild: 80% - little to no breathlessness

Moderate: 50-79% - breathless on moderate exertion

Severe: 30-49% - Breathless at rest/mild exertion, usually with wheeze and cough

Very severe: <30%

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4
Q

Asthma Phases

A

Early/Immediate Phase:
Allergen interacts with mast cell –> degranulation of mast cell –> histamine, PGD2, LT C4, LTD4

Late Phase:
Chemokines, cytokines –> WBC (leukocytes ex: T cells, neutrophils, basophils)

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5
Q

Asthma Therapy

A

Bronchodilators: relief of symptoms by blocking early phase of asthma attack caused by bronchoconstriction

Anti-Inflammatory Agents: prevention of attack by preventing late phase caused by release of cytokines

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6
Q

Bronchodilators

A
  • reverse bronchospasm

- rapid relief

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7
Q

Brochodilator types

A

β2-adrenoceptor agonists:

  • act on β-adrenoceptors (on mast cells)
  • increase cAMP –> prevent release of histamine
  • affect mucous secretion
  • increase FEV1
  • given by inhalation
  • long acting agents for long term prevention

Phosphodiesterase Inhibitors

  • Roflumilast (PDE4) inhibitor
  • COPD
  • inhibit phosphodiesterase (PDE) –> inhibit ATP into cAMP
  • Potential to enhance β-AR effects
  • Reduce inflammation

Muscarinic M-receptor anatagonists:

  • block bronchoconstriction by PNS
  • inhibit mucous secretion
  • inhalation
  • atropine: naturally occurring
  • ipratropium: non-selective
  • tiotrpium: slow dissocioation from receptor –> long-acting
  • aclidinium –> newer, long-acting
    ex: viagra –> PDE5 inhibitor
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8
Q

Desinsitisation

A

Long term use of β-adrenoceptors –> internalisation of receptors –> tolerance/desensitisation

Prevented by steroids

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9
Q

LABA

A
  • long action –> long fatty chain, absorb into lipid bilayer, keep re-attaching to receptors

salmeterol, formoterol (2x daily)

indacaterol (4x daily)

SABA (salbutamol) (4x daily)

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10
Q

β2 Adrenoceptor agonists adverse effects

A

High doses: Tremor, palpitations, hypokalaemia

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11
Q

MR Antagonists Side Effects

A
Dry mouth
Nausea/headache
Constipation
Urinary retention
Atrial Fibrilation, tachycardia and palpitation 
Blurred vision
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12
Q

Xanthines uses and method of action

A

theophylline - in tea (COPD)

aminophylline (theophylline & ethylenediamine 2:1 to imporve solubility) in emergency (Asthma, COPD)
measure plasma theophylline (toxic) 4-6 hours after start of iv infusion

PED inhibitors at a far greater dose than clinically given (probs not method of action here)

Adenosine receptor antagonist?

Anti-inflammatory effects

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13
Q

Xanthines side effects

A
Tremor, palpitations, nausea
CNS stimulation (sleep disturbance, overactivity)
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14
Q

Xanthines drug interactions

A

inhibition of metabolism increase risk of toxicity
ex: cimetidine

Induction of metabolism reduce plasma levels
ex: smoking (careful of smoking cessation)

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15
Q

Anti-Inflammatory agents

A

Preventative, does not reverse asthma attack

corticosteroids/steroids:

  • lipophilic
  • cross lipid membrane
  • act at intracellular glucocorticoid receptors
  • dimer moves across nuclear membrane
  • affect gene transcription
  • increased/decreased gene expression
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16
Q

Steroid examples and delivery

A

Inhaled:

  • beclametasone
  • budenoside
  • fluticasone

Oral:
-prednisolone (acute asthma attack)

IV & cream:
Hydrocortisone (life-threatening acute asthma

17
Q

steroids activate what genes

A

Annexin A1

β2-adreoceptors

IkB (inhibitor of NF-kB)

anti-inflammatory cytokines

18
Q

steroids repress what genes

A

Inflammatory cytokines

chemokines

inflmmatory enzymes and peptides

19
Q

Annexin 1

A
  • lipocortin
  • act through formyl peptide receptors
  • inhibit release of histamine from mast cells
  • inhibit cPLA2 leading to less leukotrienes and PGs
20
Q

Corticosteroids side effects

A
  • throat infections/oral candidiasis with ICS (wash mouth after)
  • long term –> osteoporosis (Ca+ supplements)

-Adrenal suppression in children (lowest effective dose, monitor height)
growth rate slowed not reduced

  • indigestion (oral)
  • chickenpox more severe, immune response
  • withdrawal effect (reduce oral dose gradually if >3 weeks)
21
Q

Steroid resistance

A

asthma, COPD patients have poor response to steroids

reasons:

  • genetic resistance
  • GR receptor modification
  • dec nuclear translocation of GR
  • inc efflux of steroids
22
Q

Leukotrienes

A
  • stimulate mucus secretions
  • bronchoconstriction
  • hypersensitivity to allergens
  • linked with exercise-induced asthma
  • role in airwayb remodelling
23
Q

CystenylLeukotriene receptor antagonists

A
  • act at CysLT1 receptor

- oral

24
Q

Leukotriene synthesis inhibitors

A

block synthesis of LTs and LTB4

ex: zileuton

25
Q

LT antagonists side effects

A
  • headache/rash
  • nausea, jaundice, other signs of liver toxicity (monitor levels)
  • mood disorders/suicidal thoughts with montelukast
26
Q

Omalizumab

A
  • monoclonal antibody against free IgE and prevent it from binding to immune cells and causing allergen-indu ced mediator release
  • sever allergic asthma, cannot be controlled by steroids
  • injection every 2-4 hours
27
Q

Bronchoconstriction as adverse drug reactions

A

NSAIDs

β-adrenoceptor antagnosits

Drug allergies (penicillins, excipients wtc.)

28
Q

NSAID adverse drug reaction

A

-inhibit cox, more AA, more LT, increased inflammation

29
Q

Cromones

A
  • sodium cromoglicate
  • preventative
  • inhalation.eye drops
  • may benefit exercise asthma
30
Q

Mucolytics

A

antioxidants
break up thick mucus
used in COPD

ex: carbocysteine
erdosteine

31
Q

Cough

A

-protective mechanism

32
Q

Anti-tussive agents

A

Codeine (opioid)

  • not particularly effective
  • avoid in under 18 yo

Dextromethorpan (non-opioid)

  • not particularly effective
  • 6 yo and above

Levodropropizine
-may inhibit realease of sensory neuropeptides