NUR 112 Respiratory Drugs

Mechanism of antihistamines

Block H1 receptors to prevent histamine-induced edema, itching, and bronchoconstriction.

Examples of traditional (sedating) antihistamines

Diphenhydramine (Benadryl).

Examples of non-sedating antihistamines

Loratadine (Claritin), Fexofenadine (Allegra), Cetirizine (Zyrtec).

Main adverse effects of antihistamines

Drowsiness, dry mouth, constipation, urinary retention.

What should be avoided while taking antihistamines?

Alcohol and other CNS depressants.

How do adrenergic nasal decongestants relieve congestion?

Constrict nasal arterioles, reducing blood flow and edema.

Common adrenergic nasal decongestants

Pseudoephedrine (Sudafed), Oxymetazoline (Afrin), Phenylephrine.

Side effects of adrenergic decongestants

Nervousness, insomnia, palpitations, rebound congestion if overused.

Why should nasal sprays be used for only 3-5 days?

To prevent rebound congestion (rhinitis medicamentosa).

Corticosteroid nasal sprays

Fluticasone (Flonase), Triamcinolone (Nasacort), Budesonide (Rhinocort).

Main purpose of antitussives

To suppress a dry, nonproductive cough that interferes with rest or sleep.

Two opioid antitussives

Codeine and Hydrocodone.

Two non-opioid antitussives

Benzonatate (Tessalon Perles) and Dextromethorphan (Robitussin DM).

How do opioid antitussives suppress cough?

Act on the medullary cough center in the brain and provide mild analgesia.

How does benzonatate (Tessalon Perles) work?

Numbs the stretch receptors in the respiratory tract to prevent the cough reflex.

Common adverse effects of opioid antitussives

Sedation, dizziness, nausea, constipation, respiratory depression.

Adverse effects of non-opioid antitussives (like dextromethorphan)

Drowsiness, dizziness, nausea, potential for abuse at high doses.

Essential patient teaching for antitussives

Avoid alcohol and CNS depressants; only use for dry, nonproductive coughs.

Function of expectorants

Thin and loosen mucus to make coughs more productive.

Example of a common expectorant

Guaifenesin (Mucinex, Robitussin).

Nursing advice when using expectorants

Encourage fluid intake to help break up mucus (unless contraindicated).

Mechanism of action of SABAs

Stimulate beta-2 receptors in the lungs → relax bronchial smooth muscle → bronchodilation.

Examples of SABAs

Albuterol (Proventil, Ventolin), Levalbuterol (Xopenex).

When are SABAs used?

For rapid relief of acute bronchospasm or asthma attacks ('rescue inhalers').

Adverse effects of SABAs

Tremors, restlessness, tachycardia, palpitations, anxiety, headache, hyperglycemia.

Why should SABA use be limited?

Overuse can lead to decreased bronchodilator response and more side effects.

What should the nurse assess before and after SABA use?

Respiratory rate, lung sounds, pulse, and breathing improvement.

Nursing teaching point for SABA inhalers

Use at onset of symptoms; carry inhaler; wait 1-2 minutes between puffs.

What are LABAs used for?

Maintenance and prevention of asthma and COPD symptoms; not for acute attacks.

Example of a LABA

Salmeterol (Serevent).

How long does it take for LABAs to work?

Slower onset, up to 20 minutes.

Common adverse effects of LABAs

Headache, hypertension, tremor, nervousness, muscle cramps, throat irritation.

Why are LABAs often combined with corticosteroids?

To enhance anti-inflammatory effects and improve long-term control (e.g., Advair).

Why should LABAs not be used alone in asthma?

They do not treat inflammation and may increase risk of asthma-related death.

Nursing teaching for LABAs

Take regularly (q12h), rinse mouth, report palpitations or chest pain.

Mechanism of action of inhaled corticosteroids

Decrease airway inflammation and enhance beta-2 agonist responsiveness.

Common inhaled corticosteroids

Fluticasone (Flovent), Budesonide (Pulmicort), Beclomethasone (Beclovent).

Fluticasone

A type of inhaled corticosteroid (Flovent).

Budesonide

A type of inhaled corticosteroid (Pulmicort).

Beclomethasone

A type of inhaled corticosteroid (Beclovent).

Local adverse effects of inhaled corticosteroids

Oral thrush, hoarseness, sore throat, cough, dry mouth.

Systemic adverse effects of corticosteroids

Hyperglycemia, infection risk, osteoporosis, edema, mood changes, adrenal suppression.

Prevention of oral thrush from ICS

Rinse mouth and spit after each use.

Tapering corticosteroids after long use

To prevent adrenal crisis due to suppressed cortisol production.

Signs of corticosteroid overuse

Moon face, weight gain, hypertension, edema, mood swings.

Combining LABA with corticosteroid

For both bronchodilation and inflammation control.

Difference between inhaled and systemic corticosteroids

Inhaled act locally with fewer systemic effects; systemic affect entire body.

Early signs of oral fungal infection from ICS

White patches or soreness in mouth or throat.

Use of systemic corticosteroids

During acute asthma or COPD exacerbations for rapid anti-inflammatory effect.

Examples of systemic corticosteroids

Methylprednisolone (Solu-Medrol), Prednisone, Dexamethasone.

Systemic corticosteroid adverse effects

Immunosuppression, hyperglycemia, osteoporosis, fluid retention, mood changes, thin skin, bruising.

Typical duration for acute corticosteroid therapy

7-10 days, then taper.

Monitoring for IV corticosteroid therapy

Blood glucose, electrolytes, infection signs, and weight.

Mechanism of leukotriene receptor antagonists

Block leukotriene receptors → reduce inflammation, bronchoconstriction, mucus.

Example of a leukotriene antagonist

Montelukast (Singulair).

Use of leukotriene antagonists

Prevention and long-term control of asthma.

When to take Montelukast

Once daily in the evening.

Why not use Montelukast for acute asthma attacks

It's for maintenance and prevention, not immediate relief.

Adverse effects of Montelukast

Headache, nausea, diarrhea, mood changes.

Example of a phosphodiesterase-4 inhibitor used in COPD

Roflumilast (Daliresp).

Main adverse effect of Roflumilast

Psychiatric symptoms like depression or suicidal thoughts.

Example of a monoclonal antibody for asthma

Omalizumab (Xolair).

Mechanism of Omalizumab

Binds IgE to prevent release of allergic mediators.

When is Omalizumab used

Moderate to severe asthma uncontrolled by other meds.

How is Omalizumab given

Subcutaneous injection every 2-4 weeks.

Main risk of Omalizumab

Anaphylaxis — first dose given under medical supervision.

8 steps for using a metered-dose inhaler (MDI)

Shake, remove cap, exhale, seal lips, press canister, inhale slowly, hold breath 10s, wait 1-2 min before 2nd puff.

Importance of proper inhaler technique

Ensures full medication delivery and prevents mouth irritation.

What is a spacer used for

Improves coordination and drug delivery from MDIs.

Who benefits most from a spacer

Children, elderly, or those with poor coordination.

What is a nebulizer

Device that converts liquid medication into mist for inhalation.

When are nebulizers used

For severe asthma/COPD or patients who can't use inhalers properly.

What does a peak flow meter measure

Patient's expiratory flow rate to monitor airway obstruction.

When should peak flow readings be taken

Daily at the same time; record best of three attempts.

What is the 'personal best' in peak flow monitoring

Baseline measurement used to detect worsening symptoms early.

Drugs that can cause rebound congestion

Adrenergic nasal decongestants (like Afrin) when overused.

Conditions contraindicating adrenergic decongestant use

Hypertension, heart disease, glaucoma.

Respiratory drugs that can cause tremors and tachycardia

Beta-2 agonists (SABA and LABA).

Drug class requiring serum monitoring

Xanthines (Theophylline — 10-20 mcg/mL).

Teaching for all inhaled medications

Clean devices, use bronchodilator before steroid, don't exceed doses.

The four 'R's of corticosteroid nursing care

Reduce inflammation, Rinse mouth, Regular use (not PRN), Report infection signs.