Respiratory Flashcards
Antihistamine uses
Allergies
Uticaria and pruritis
Anaphylaxis in combination with adrenaline
Antihistamine MOA
Antagonis H1 receptor, blocking effects of histamine in the inflammatory response
Antihistamine ADRs
Sedation (1st gen more than 2nd gen)
Antihistamine ADRs
1st Gen: sever liver impairment- may lead to hepatic encephalopathy
Long acting antimuscarinincs
Tiotropium, umeclidinium, glycopyrronium, aclidinium
Short acting antimuscarinics
Ipratropium
Antimuscarinic indications
COPD: SA- breathlessness relief, LA- breathlessness prevention
Asthma: SA breathlessness relief (alongside SABA), LA- breathlessness prevention alongside high dose ICS and LABA
Antimuscarinic MOA
bind to muscarinic receptors, competitively inhibiting acetylcholine. They increase HR and conduction, and reduce smooth muscle tone in the respiratory tract and bladder, they also reduce secretions from glands in respiratory tract, GI. They relax pupilary constrictor causing pupil dilation.
Antimuscarinic ADRs
Respiratory tract irritation (sinusitis, cough, nasopharyngitis), GI disturbances (dry mouth, constipation), urinary retention, blurred vision, headaches. ADRs more likely with oral/IV use than inhaled.
Antimuscarinics warnings
angle-closure glaucoma, arrhythmias, urinary retention. Usually not a problem if inhaled
B agonist indications
asthma: SABA- breathlessness, LABA- in addition to ICS for management (always needs to be given in combination to ICS).
COPD: SABA- breathlessness, LABA- second line symptom relief.
Hyperkalemia
B agonist MOA
Stimulate B receptor, found in smooth muscle activating cascade leading to smooth muscle relaxation. Stimulate Na/K ATPase pumps on cell surface membranes, causes shift of K into cells from extracellular matrix.
SABAs
salbutamol, terbutaline
LABAs
salmeterol, formoterol
B agonist ADRs
Fight or flight responses (tachycardia, palpitations, anxiety, tremor). Promote glycogenolysis (increasing serum glucose). High dose: raised lactate. LABAs: muscle cramps
B agonist warnings
LABA- asthma- must be used with ICS, as monotherapy associated with increased asthma deaths.
Cardiovascular disease- tachycardia may provoke angina/arrhythmias
B agonist interactions
B blockers- may worsen symptoms
Nebs and theophylline and corticosteroids - hypokalaemia
Gas for driving nebulisers
Generally speaking oxygen for asthma, medical air for COPD (CO2 retention risk)
ICS indications
asthma: treat airway inflammation
COPD: control symptoms and exacerbations. Usually with LABA.
ICS MOA
Activate receptor in cytoplasm, modifying transcription of large number of genes, such as down regulation of pro-inflammatory interleukins, cytokines and chemokines. This reduces mucosal inflammation, widening airways and reduces mucus secretion.
ICS ADRs
Oral candidiasis, sore throat. COPD: increased risk of pneumonia. little systemic effect (unless high dose, which can cause adrenal suppression, slow growth in children and osteoporosis).
ICS warnings
COPD- High dose ICS, in particular fluticasone - history of pneumonia, children.
ICS interactions
No clinically significant interactions
ICS counselling points
Rinse mouth after use, wash inhaler
MDI counselling points
Slow and deep breaths
DPI counselling points
Teach how to use device. Need quick and deep inhalation. If capsule (ie zonda) inhale contents, not take
Spacer counselling points
Tidal breathing, rinse with water and let air dry, do not towel dry
ICS and disease progression
Asthma- can prevent progression, prevents remodelling caused by inflammation
COPD: does not prevent progression
Montelukast indications
Asthma:
Adults- add on if ICS and LABA unsuccessful
Children 5-12 - as alternative to LABA as an add on with ICS being insufficient
Children 5 and under - first line preventative if unable to take ICS
Montelukast MOA
Block CysLT1 receptor, reducing inflammatory response (Leukotrienes produced by mast cells and eosinophils activate CysLT1, producing inflammatory cascade)
Montelukast ADRs
Headache and abdo pain common and mild. URTIs.
Uncommon- hyperactivity and loss of focus.
Churg Strauss syndrome (an eosophillic autoimmune disorder, might not be ADR of drug)
Montelukast in Pregnancy
No evidence of safety, no harmful effects demonstrated. Reasonable to continue if efficacious and alternatives not.
Montelukast ADRs
None with commonly used drugs.
