1207 Module 5 (Respiratory System) Review

What is allergic asthma?

Asthma symptoms induced by a hypersensitivity reaction upon exposure to environmental allergens

What is hyperventilation?

Deep and rapid respiration

• High oxygen and low carbon dioxide in blood = hypocapnia

• Increase in blood pH

• Breathing stopped as respiratory control centre not stimulated

What is hypoventilation?

Insufficient are enters alveoli

• Respiratory obstruction, lung disease, depression of respiratory center (drugs)

• Increase in carbon dioxide, decrease in blood pH

What is cyanosis?

Not enough oxygen in blood (blue)

What is hypoxia?

Lower than normal oxygen level in tissues

What is hypoxemia?

Lower than normal oxygen concentration in arterial blood

What is asthma?

An inflammatory disorder of the airways characterized by paroxysmal or persistent symptoms such as:

• Dyspnea

• Chest tightness

• Wheezing

• Sputum production and cough

What are the 4 characteristics of asthma?

1. Paroxysmal or persistent symptoms (dyspnea, chest tightness, wheezing, sputum production and cough)

2. Variable airflow limitation

3. Airway inflammation

4. Airway hyper-responsiveness

What are some non-pharmacological interventions for asthma?

• Identify and avoid

• Smoking cessation and avoidance of second-hand smoke

• Annual influenza immunizations

• Patient and parent education about the chronic nature of asthma

• Hyposensitization therapy to allergens generally is not useful in the management of asthma

What are some OTC precautions for asthma?

Avoid ASA and NSAIDS in patients with aspirin-exacerbated respiratory disease (AERD) and in high-risk patients (severe asthma symptoms, nasal polyps, urticaria or chronic rhinitis)

How are short-acting inhaled beta2-agonists (SABAs) used in asthma?

• PRN use is preferred; also known as rescue inhalers

• Patient is recommended to start inhaled corticosteroids if SABA use > 4 doses/week

What are the adverse effects of SABAs?

• Nervousness

• Tremors

• Tachycardia

• Palpitations

How are long-acting inhaled beta2-agonists (LABAs) used in asthma?

• Regular dosing BID

• Used only when patient is already using ICS

• May be especially useful for preventing nocturnal asthmatic symptoms

• Helps prevent exercise-induced bronchospasm

How are inhaled corticosteroids (ICS) used in asthma?

• Used regularly (once daily-BID) at lowest effective dose

• First-line mono therapy for asthma control

• ICS has higher topical activity compared to oral corticosteroids

• For patients with risk factors for osteoporosis and/or require high doses of ICS therapy, bone densitometry is suggested

• Patients with personal/familiy history of glaucoma, and need high doses of ICS, should have IOP checked soon after starting therapy, as well as periodically thereafter

What are the adverse effects of ICS?

Sore mouth/throat, dysphonia, oral thrush

How are systemic corticosteroids used in asthma?

• No optimal dose has been established

• Short term use is recommended to minimize adverse effects (fluid retention, glucose intolerance, hypertension, increased appetite, mood alterations, weight gain)

• Typically prescribed for 1-2 weeks after acute exacerbation

What are the common adverse effects of leukotriene receptor antagonists (LTRAs)?

• Headache, nausea/diarrhea (Accolade), abdominal pain/flu-like symptoms (Singulair)

• URTI

What is omalizumab (Xolair) indicated for in asthma?

Moderate to severe persistent asthma in those who have had a positive skin test or in vitro reactivity to a perennial aeroallergen and whose symptoms are inadequately controlled with high-dose ICS and add-on therapy

• >= 12 year old

• SC injections q2-4 weeks

What are anticholinergic agents indicated for in asthma?

• Useful for patients who are susceptible to beta2-agonists’ adverse effects (e.g. tremor, tachycardia)

• Atrovent: alternative for acute relief

• Spiriva: alternative for maintenance

What are the adverse effects of anticholinergic agents for asthma?

Dry mouth, metallic taste, mydriasis and glaucoma if released into the eye

What are the drugs of choice for asthma in pregnancy?

• SABA and ICS — extensively used (esp. budesonide), safe for pregnancy

• Theophylline, while considered safe for use during pregnancy, may worsen GERD and can cause nausea

What is the pathophysiology of nicotine addiction?

• Acts as a stimulant, increasing alertness, sense of well-being, heart rate (HR) and blood pressure (BP)

• Highly addictive nature is due to rapid delivery

• With continued use, tolerance to nicotines effects develop

What are signs of nicotine addiction?

• Cravings for continued smoking

• Tendency to increase usage

• Profound physical and psychological symptoms upon withdrawal

How do nicotine withdrawal symptoms usually present?

• Physiological effects: usually peaks at 24-72 hours after last cigarette; subsides at approximately 2 weeks

  • CNS/psychiatric: dysphoria/depressed mood, irritability, anxiety, difficulty concentrating, restlessness, headache, insomnia

  • GI: increased appetite/weight gain, gastrointestinal symptoms

• Craving can last for years; most likely due to behavioural and psychological aspects

What are some non-pharmacological interventions for nicotine addiction?

• Counselling by health professionals

• Behavioural modification programs

What are the 5 evidence-based steps required for successful quitting of nicotine?

1. Set a target quit date

2. Get professional help

3. Enlist social support

4. Use medication to quit smoking

5. Use problem-solving methods of counselling to quit and remain smoke free

When should pharmacological treatments be offered for nicotine addiction?

To all patients who smoke more than 10 cigarettes/day AND wish to quit

• Exceptions: contraindications to drug therapy, populations less likely to benefit from pharmacotherapy (e.g. adolescents)

What is nicotine replacement therapy (NRT)?

• Long safety record

• Readily available (OTC)

• Raises the rate of smoking cessation by 50-70%

• Nicotine topical patches are long-acting

• Nicotine gums/inhalers/lozenges/mouth sprays offer flexibility; short acting

What are the adverse effects of NRT?

• CNS: depression, anxiety, irritability, insomnia, dizziness, weakness, headache

• Gastrointestinal: changes in taste perception, hiccoughs, dyspepsia, nausea/vomiting

• CV: hypertension, palpitations, tachycardia, chest pain

• Skin: erythema, itching, rash, urticaria

• Respiratory: dyspnea, cough, voice hoarseness, sneezing, wheezing

What are the absolute contraindications for NRT?

• Life-threatening arrhythmia

• Within 2 weeks after an MI episode

• Severe angina pectoris

• History of recent stroke

• Temporomandibular joint (TMJ) disease (for gums/lozenges)

• Generalized skin disorders, such as severe psoriasis or eczema (patches)

What are some relative contraindications for NRT?

• Pregnancy

• Smoking while using NRT (risk of nicotine toxicity)

• Breastfeeding

• Age < 18 years old

What does varenicline (Champix) do?

Nicotinic receptor partial antagonist

• Achieves higher quit rate than bupropion and single forms of NRT

What are the dosage recommendations for varenicline (Champix)?

• Available as tablets

• 0.5 mg once daily for 3 days then BID for 4 days, then 0.5-1 mg BID for 12 weeks

• Patients should quit smoking 1-2 weeks after starting the drug therapy

• Treatment should be re-assessed if patient continues to smoke after 4 weeks

• 1mg BID is the usual maintenance dose, it can be lowered to 0.5mg BID if adverse effects aren’t tolerated (e.g. uncontrolled nausea, despite increased water consumption and taking the medication on a full stomach)

• Tapering is not needed when discontinuing varenicline

What are the adverse effects of varenicline (Champix)?

• Nausea (30%)

• Insomnia; suggest taking 2nd dose at suppertime, not bedtime

• Neuropsychiatric adverse effects like suicidal/homicidal ideation have been reported

What are the contraindications for varenicline (Champix)?

Combining varenicline with NRT — can increase the risk of adverse effects

What does bupropion (Zyban) do?

Weak norepinephrine, serotonin, and dopamine reuptake inhibitor

• Chemically unrelated to nicotine

• 150 mg daily for 3 days, then 150 mg BID for 7-12 weeks

• Begin 1-2 weeks before the selected quit date

• May be used with NRT; monitor for treatment-emergent high BP

• Tapering after is unnecessary

• BID dosing should be >= 8 hours apart

What are the adverse effects of bupropion (Zyban)?

• Common: insomnia, dry mouth, dizziness, restlessness, difficulty concentrating

• Uncommon: agitation-type reactions involving mood/behavioural changes

What are the contraindications of bupropion (Zyban)?

• History of head trauma

• History of seizure/current seizure disorder

• Current/prior diagnosis of bulimia/anorexia nervosa

• Patient is concurrently undergoing abrupt withdrawal from alcohol/benzodiazepines/other sedatives

• Dose > 300mg/day for smoking cessation (bupropion-induced seizures are dose-related)

What is chronic