Medications for Respiratory Diseases Flashcards
Drugs given by inhalation
=Bronchodilators (open up airways!)
a. beta2-agonist
- short-acting (SABA)
- long-acting (LABA)
b. muscarinic antagonists
- short-acting (SAMA)
- long-acting (LAMA)
c. inhaled corticosteroids (ICS)
d. various combos of the above
Aerosol
mixture of particles suspended in a gas
- inhalation devices produce medication aerosol with particle size in ‘respirable range’
Advantages and Disadvantages of Inhalers
Advantages:
- drug delivered directly to site of action
- minimal systemic effects
- rapid relief of acute attacks
- portable, durable devices
Disadvantages:
- technique may be difficult for some
- poor technique causes reduced efficacy and increased side effects
Metered Dose Inhalers (MDIs)
= pressurized canisters of drug and propellant
~ 10% of dose reaches lungs, (~20% with spacer)
a. ‘press and breathe’, requires hand-lung coordination
b. shake prior to use
c. reduced efficacy if canister is cold
MDI Technique
- sit/stand with back straight
- shake inhaler, breathe out normally
- wrap lips around mouthpiece, take a slow deep breath in, press on inhaler while breathing in slowly
- hold breath between 5-10 seconds
- breathe out normally
* wait one minute if need second puff - rinse mouth to cut down on side effects: thrush (yeast infection causing white coating) or sore throat (from ICS)
Dry Powder Inhalers (DPIs)
= breath-activated, easier to use (less hand-lung coordination), multi-dose device
~20%..better drug delivery than MDI
powder may be pre-loaded in device or may require loading of separate dry powder capsule
**biggest problem: inadequate inspiratory flow rate
additives may cause cough and irritation
Turbuhaler (DPI) Technique
- holding Turbuhaler upright, turn coloured wheel one way and back until it clicks to load a new dose
- breathe out normally
- put mouthpiece between lips and tilt head back slightly
- breathe in deeply and forcefully
- hold breath for 10 seconds
- remove Turbuhaler and breathe out
* repeat if need another dose - if contains corticosteroid, rinse with water and spit out
Respimats
= ‘press and breathe’ multi-dose, no propellant (works like handheld nebulizer), requires less hand-lung coordination and little inspiratory effort
up to 50% drug delivery to lungs
generates smaller particle size to increase lung delivery and reduce deposition in mouth and throat
**drawback: expensive, not many drugs available in this format, device must be assembled and primed
Nebulization
= nebulizer converts drug solution into a mists which is inhaled via face mask or mouthpiece
~10% of dose delivered to lower airways
takes longer to deliver compared to MDI or DPI
Advantages and Disadvantages of Nebulization
Advantages:
- requires less coordination, good for acute attacks, anxious patients
Disadvantages:
- higher dose than MDI or DPI»_space; more side effects
- more expensive
- care/maintenance required
- not portable
Nurse’s Role in proper inhaler use
a. assess for potential barriers
- patient impairment
- side effect
- device issue
- coordination (especially in elderly)
b. assess patient technique and provide detailed instruction
Relievers (bronchodilators for intermittent symptoms)
for PRN use only
a. short-acting beta2 agonists
b. anticholinergic (less often)
Controllers (maintenance therapy)
for prevention on a fixed schedule
a. anti-inflammatory medications
- inhaled and oral corticosteroids (reduce inflammation and immune system activity)
- LTRAs, anti-allergic agents
b. bronchodialtors
- long-acting beta2 agonist
- theophylline
- anticholinergics (rarely)
Adrenocortical Steroid Hormones
“corticosteroids”
- Glucocorticoids
- regulate carbohydrate metabolism (blood sugar), regulate body’s response to stress
* cortisol is most important - Mineralocortcoids
- regulate electrolyte, salt wand water balance (blood pressure)
* aldosterone is most important - Androgens
Effects of Corticosteroids
Low dose/levels produce physiologic effect
High dose/levels produce pharmacologic effects - treat asthma
a. carbohydrate, fat and protein metabolism, glucose production and storage
b. cardiovascular
- increase blood pressure from Na+/H2O retention, increase RNB, Hgb, WBC
c. CNS
- excitation, insomnia, euphoria, psychosis
d. increase gastric acid production
e. decrease calcium absorption and increase excretion
f. immunosuppression
g. anti-inflammatory
Corticosteroids
= anti-inflammatory actions in asthma
a. decrease synthesis and release of mediators
b. decrease inflammatory cell infiltration, reduce airway edema
c. reduce bronchial hyper-reactivity, reduce mucus
d. increase b2-receptors and responsiveness to b agonists»_space; dilation
Corticosteriods in respiratory disorders
SLOW ONSET, do not relieve acute symptoms
Asthma
- prophylaxis on a fixed schedule to reduce incidence and severity of acute attacks
COPD
- acute exacerbations, chronic stable disease
Using corticosteroids in asthma
Inhaled (ICS)
- first-line therapy except for very mild cases
Onset: days, max effect in 3 months
Prototype: FLUTICASONE
Oral (OCS)
- reserved for severe asthma when symptoms cannot be controlled with other meds
- limit dose/duration of use as much as possible
Protoype: PREDNISONE
Side effects of ICS
very little systemic exposure and toxicity
Due to local deposition:
- dysphonia (difficulty speaking)
- oropharyngeal candidiasis (“thrush”, yeast infection)
- *gargle or use spacer
Long term high doses:
- bone loss in women
- adrenal insufficiency
- exacerbation of glaucoma
Side effects of OCS
notable with pharmacologic doses
Short term:
- GI intolerance, n/v, diarrhea, cramps
- glucose intolerance
- hypertension
- edema
- psychologic disturbances
- insomnia
Long term: Cushingoid features - too much cortisol
- adrenal insufficiency
- osteoporosis, avascular necrosis
- glaucoma, cataracts
- body fat redistribution (moon face, buffalo hump, truncal obesity)
- dermatologic effects (skin atrophy, purpura, telangectiasis, poor wound healing)
- stunted growth
- increased risk of infection
