Respiratory Flashcards
Antihistamines- Therapeutic uses
Therapeutic Uses-
Mild allergy/Seasonal allergic rhinitis
Severe allergy
Benefits may be limited, use as adjunct only,
Motion sickness,
Insomnia,
Common cold
Anticholinergic effects decrease rhinorrhea. Not cure to treat symptoms
Antihistamines- Adverse Effects
Sedation(First generation more than second and third generations)
Dizziness, incoordination, confusion, fatigue, GI upset
(Take with food)
Anti-cholinergic effects-Drying of mucus membranes, Urinary hesitancy, constipation, palpitations
Promethazine (Respiratory depression and local tissue injury-IV site)
Paradoxical reaction in kids - sedative purposes, and now kids are wired- nervousness, insomnia, tremors
ex: Benadryl
Antihistamine- Drug Interactions
ETOH Barbiturates Benzodiazepines Opioids Sedatives CNS depressants Tricyclic antidepressants MAO inhibitors Ototoxic drugs
Space medication administration out to avoid interactions
What is histamine?
Locally acting compound Effects vary by system High levels in skin, lungs and GI tract Low levels in plasma Can be used in diagnostic procedures
What happens in response to histamine?
H1 receptors (Skin & lungs) Vasodilation (BP& Total peripheral resistance goes down) Increased capillary permeability = edema Bronchoconstriction CNS effects Itching Secretion of mucus H2 Receptors Secretion of gastric acid- Histamine dominant over acetylcholine and gastrin
Pharmacologic Effects of Blocking H1 Receptors
Prevents vasodilation(mostly face & upper body) =reducing flushing
Decreased capillary permeability=reducing edema
Increased drowsiness
Decreased bronchoconstriction
Decreased itching and pain (blocks at a sensory receptors)
Decreased mucus secretion
Antihistamines MOA
Similar histamine antagonist 1 actions
First generation is more sedating ex: Benadryl
Second generation is much less sedating ex: Zyrtec, Claritin, Allegra
Selectively bind to H1-histamine receptors
Antihistamines- Contraindications/ Warnings
Pregnancy
Reports of fetal malformations
Benefits vs. risks
Avoid in 3rd trimester- newborns and infants are very sensitive to antihistamines
Lactation
Excreted in breast milk
Acute toxicity
Dilated pupils, flushed face, hyperpyrexia,
tachycardia, dry mouth, urinary retention
In kids CNS excitation
Can progress to coma, cardiovascular collapse and
death
Diphenhydramine
First generation antihistamine- Ethanolamines
Avoid as a sedative in children- Paradoxical excitation in kids
Can be very sedating
Use lower doses if possible
Not used freely as sedative for children
If used for insomnia, potential tolerance could be built up. If used for sleeping do so occasionally not regularly.
Technically not enough to treat insomnia therapeutically.
Caution with elderly
Fexofenadine
2nd generation anithistamine Available OTC pretty safe drug Reduce doses in renal failure Avoid fruit juices 4 hours before administration and 1-2 hours after Good combination of efficacy and safety among 2nd generation drugs Given to kids as young as 6 months comes as liquid(helpful for kids)
Cetirizine
2nd generation anithistamine
Available OTC
Reduce doses in renal and hepatic impairment
Food delays absorption
More sedating than other 2nd generation antihistamines
may work best on empty, but if nauseous give with food
Levocetirizine
Available OTC
Contraindicated for children with any renal impairment
Reduce dose for mild to moderate renal impairment
More sedating than other 2nd generation antihistamines
Therefore, Take in the evening, so you won’t notice the effects as much.
given with food or not
Loratadine
2nd generation antihistamine (“big group”)
Available OTC
Food delays absorption
Dose every other day for significant renal or hepatic impairment
Extensive hepatic metabolism
Azelastine (Astelin, Astepro)
Intranasal 2nd generation antihistamine
Astelin is not approved for children under 12
Astepro is approved for children 5-11
Can cause drowsiness, nose bleeds, headaches and an unpleasant taste-all the things that happens with internasal spary
Antihistamines- Contraindications/ Warnings
Pregnancy Reports of fetal malformations Benefits vs. risks Avoid in 3rd trimester Lactation (AVOID) Excreted in breast milk Acute toxicity(d/c meds) Dilated pupils, flushed face, hyperpyrexia, tachycardia, dry mouth, urinary retention In kids CNS excitation Can progress to coma, cardiovascular collapse and death
Asthma
Chronic inflammatory disease of the airway
Caused by immune-mediated inflammation of the airway
Treatment both inflammation and bronchoconstriction
Wheezing (sense of breathlessness), tightness of chest, dyspnea, cough
COPD
Smoking causes an inflammatory reaction
pt edu: smoking cessation-slowly decrease the daily amount of cigs
Maybe chronic bronchitis, emphysema, or both
Chronic bronchitis is from hypertrophy of mucus-secreting glands in the airway epithelium
Emphysema is an enlarged airspace between the bronchioles and alveoli due to the deterioration of the surrounding walls
Chronic, progressive and mostly irreversible
prevent from getting worse
Hypoxia, excessive sputum, wheezing, dyspnea, poor exercise tolerance, chronic cough
Asthma and COPD Drug Overview
Anti-Inflammatory Agents
Glucocorticoids
Usually inhaled
Fixed schedule
Used prophylactically- prevent inflamamtion
Bronchodilators
Beta2 agonists
Usually inhaled
Fixed schedule used for long term control
PRN used for acute attacksGlucocorticoids: Therapeutic Uses
Most effective drug for long term control of airway inflammation
Suppress inflammation
Reduced bronchial hyperreactivity
Decreased airway mucus production
Decreased synthesis & release of Inflammatory mediators
Increased infiltration and activation of inflammation cells
Decreased edema in airway mucosa Inhaled First line therapy for asthma Use daily with persistent/chronic asthma More effective and safer
Oral
Moderate to severe persistent asthma
Management of acute exacerbations in asthma and COPD
Treatment should be as BRIEF as possible- otherwise use inhaled- less adverse effects
COPD-treat IV Steroids
Glucocorticoids: Adverse Effects In
Inhaled
Adrenal suppression- really large doses
Oropharyngeal candidiasis-rinse out mouth to prevent thrush
Dysphonia- damage to vocal chords
Growth suppression in children-May slow growth in children, but not height- pt ed: reassure parents still full height
Osteoporosis-Bone loss with long term use- give calcium
Glaucoma and cataracts with continuous use of high
doses- use lowest dose possible
and risk of lost airway greater than possible blindness
Oral
No significant adverse effects with doses less than 10
days
Adrenal suppression- not often but the most serious
Hyperglycemia- most often
Peptic ulcer disease
Glucocorticoids: Warnings/ Contraindications
Discontinue long term treatment slowly, not abruptly
Will not abort an acute asthma attack i.e. don’t use for acute asthma attacks
Inhaled is preferred to oral
Inhaled Glucocorticoid: Fluticasone Propionate
Flovent HFA is a MDI
Flovent diskus is a DPI
Administered on a fixed schedule
To prevent worsening pathophysiology and attacks
Leukotriene Modifiers: Montelukast
Used for prophylaxis and maintenance of asthma, prevention of exercise induced bronchospasm and to treat allergic rhinitis
Blocks receptor activation by leukotrienes
Few drug interactions besides phenytoin
Generally well tolerated
2nd line therapy if glucocorticoids don’t work
adjunct therapy
Adv effects: Suicidal thinking and suicidal thoughts- screen pts.
safe for kids as old as one
Bronchodilators
Symptomatic relief of asthma and COPD
Do not alter the underlying inflammation
Usually adjunct therapy
Monotherapy in mild asthma with infrequent attacks
Includes Beta2-adrenergic agonists, methylxanthines and anticholinergic drugs
used in acute attacks
Short Acting Beta2 Agonist (SABA)
• Use o Abort asthma attack o Prevention of exercise induced bronchospasm (EIB) -Can be used in long term control, but taken frequently Inc frequency of drug intake in # of attacks go up -Short half-life • Route o Nebulized if severe attack o MDI o DPI • Adverse Effects o Tachycardia, angina, tremor • Contraindications/ Warnings o Step up therapy if using > 2x/week o Avoid in stable COPD (use LABA)
Long Acting Beta 2 Agonist (LABA)
Use
o Long term control in patients who have frequent asthma attacks, must be combination therapy in asthma
o Stable COPD
- ALL COPD
-long acting=long half-life=long-term control
-long half-life so you’ll take them less frequently
• Route
o Inhalation
o PO
• Adverse Effects
o Inhaled: increased risk of death in asthma if monotherapy
o PO: angina, tachydysrhythmias, tremor
• Contraindications/ Warnings
o Can’t stop an acute attack
o Avoid as monotherapy
Albuterol
PO beta2-adrenergic agonist
Can cause tremors, insomnia, and tachycardia- Watch HR
Can be used for long or short term control
Dosing may be 3-4 times daily
Often inhaled, but can be PO
Selective for beta2 in recommended doses- nebulizers
Levalbuterol
Inhaled SABA Usually a MDI/nebulizer PRN for acute attacks Take before exercise to prevent exercise induced bronchospasm (EIB) short-acting drug
Salmeterol
Inhaled LABA
Fixed schedule
Use with glucocorticoid, in same inhaler if possible (ideally)
May need to increase frequency of dosing with continued use
Frequently combined with fluticasone
Methylxanthines: Theophylline
Cause CNS excitation, bronchodilation
Used to prevent asthma attacks at night and stable asthma
COPD: use beta2-adrenergic agonists and glucocorticoids first
Check drug levels, LFTs
Interacts with caffeine, tobacco and marijuana smoke
Salmeterol
Inhaled LABA
Fixed schedule
Use with glucocorticoid, in same inhaler if possible
May need to increase frequency of dosing with continued use
Frequently combined with fluticasone
Methylxanthines: Theophylline
Cause CNS excitation, bronchodilation
Used to prevent asthma attacks at night and stable asthma
COPD: use beta2-adrenergic agonists and glucocorticoids first
Check drug levels, LFTs
Interacts with caffeine, tobacco and marijuana smoke
Anticholinergics: Ipratropium
Improve lung function by blocking muscarinic receptors in the bronchi, leading to bronchoconstriction
FDA approval for COPD, but used off-label for asthma
Inhaled, so minimal systemic effects
Adverse effects are dry mouth, pharynx irritation
Treatment Goals in Asthma
Reducing impairment
Preventing chronic and troublesome symptoms
Reducing use of SABAs for symptom relief to 2 or less days/ week
Maintaining as normal of lung function as is possible
Maintaining normal activity levels
Meeting patient and family expectations regarding asthma care
Reducing risk
Preventing recurrent exacerbations
Minimizing need for ER visits or hospitalizations
Preventing progressive loss of lung function
Providing maximum benefits with minimum adverse effects
Treatment Goals in COPD
Improve the patient’s health status and exercise tolerance
Reduce risks and mortality by preventing progression of COPD and preventing and managing exacerbations
Phenylephrine
Sympathomimetics Available nasally and PO Fast and effective when used topically Not as effective when used PO Not associated with abuse Used IV to treat hypotension
Expectorants: Guaifenesin
Stimulates respiratory secretions, making coughs more productive
May need higher than recommended doses to be effective
Often combined with dextromethorphan
Other Medications for Allergic Rhinitis
Antihistamine/sympathomimetic combos Antihistamine/glucocorticoid combos Ipratropium Montelukast Omalizumab
Antitussives
Opioids Dextromethorphan Other Non-opioids Most effective Abuse potential is low Most effective OTC Diphenhydramine Benzonatate
Cold remedies: combination preparations
Treat symptoms Usually a combination of: Nasal decongestant Antitussive Analgesic Antihistamine Caffeine
Cold remedies in children
No proof of efficacy or safety in children
Known potential for harm (including death)
FDA does not recommend OTC cold remedies in children under 2 years
FDA is reviewing the safety of these drugs in children 2-11 years
American Academy of Pediatrics recommends avoiding until 6 years
Measure carefully and accurately
Do not use to sedate children
Ephedrine
Sympathomimetics Only administered PO Higher incidence of CNS stimulation Can be converted to methamphetamine Restrictions of amount purchased More effective than phenylephrine
Pseudoephedrine
Sympathomimetics Only administered PO Cns stimulation is lower Can be converted to methamphetamine Restrictions of amount purchased More effective than phenylephrine
Epinephrine
is drug of choice for severe allergies
not an antihistamine
in emergency you can give Benadryl if epi not available
Inhalation Drug Therapy
Advantages
Enhanced therapeutic effects
Fewer systemic effects- b/c it's contained within the lungs
Rapid relief of acute attacks
Types
Metered-dose inhalers (MDIs)
Respimats
Dry-powder inhalers (DPIs)
NebulizersMDI
metered dose w/ each activation or inhalation
problem: the entire dose isn’t absorbed.
Spacers
reduces the need for the hand-breath coordination
reduced bronchospasm that occurs with sudden intake of inhaled drugs
Respimats
fine mist activated by no propellent
most of the drug reaches site b/c particles are so small
BUT not all drugs come like this
DPIs
Dry Powder Inhalers; breath activated = no hand-breath coordination needed.
20% makes it the lungs which is a fair amount
First and Second Generation Antihistamines
First Generation 5 major categories Alkylamines Ethanolamines-Diphenhydramine Phenothiazines Piperazines piperidines
Second Generation 5 PO drugs Cetirizine- Zyertec Fexofenadine** - Allegra Loratadine- Claritin Levocetirizine- Xyzal Desloratadine- prescription - not often used
2 intranasal drugs
Azelastine - Astelin/Astepro
Olopatadine
First and Second Generation Antihistamines differences
1st gen Sedation is common Significant anticholinergic properties Generally less expensive 2nd gen Less sedating Fewer anticholinergic effects Usually more expensive
EBP: General Tips for Physical Activity and Exercise for Asthma Patients
Take all you medications as prescribed
Ask about medications for before you exercise
Have you rescue medication handy
Perform a 15 minute warm-up and cool-down
Postpone exercise if symptoms are not well controlled or you have a cold or respiratory infection
Check the air quality index- stay inside if pollution or allergen levels are high
Breathe through the nose as much as possible
When outdoors, avoid areas with a lot of allergens or irritants
When indoors, keep windows and doors closed to reduce allergen exposure
Promoting physical activity and exercise in patients with asthma and chronic obstructive pulmonary disease.
EBP: Asthma in Pregnancy
Asthma is the most chronic condition seen in pregnancy
Pregnant asthmatics have increased risk of preterm birth, intrauterine growth restriction, pregnancy-induced hypertension, preeclampsia. Their babies have an increased risk of congenital malformations of nervous, respiratory and digestive systems at birth and respiratory disease later
These women need to continue to take their asthma medications and should work to control symptoms
The pregnant patient with asthma: Assessment and management.
