Respiratory Drugs

Classification of acetylcysteine (Mucomyst)

Mucolytic

Action of acetylcysteine (Mucomyst)

Breaks up linkages or bonds of mucoprotein molecules of respiratory secretions into smaller, more soluble, and less viscous strands. Also effects similar changes in DNA and cellular debris. Most effective at pH 7-9. → breaks up mucus into smaller units

ADRs of acetylcysteine (Mucomyst)

Few. Some N/V, probably due to order; stomatitis (inflammation in the tissue lining your mouth or lips), rhinorrhea (runny nose). Bronchospasm may occur in asthmatics

Special Information of acetylcysteine (Mucomyst)

1) Has unpleasant “rotten egg” odor

2) Wash face after nebulization to remove sticky coating left by the drug

3) oral (72-hour protocol) or IV infusion (21-hour protocol)

4) Antidote for acetaminophen overdose

Classification of guaifenesin (Robitussin)

Expectorant, Bronchomucotropic

Action of guaifenesin (Robitussin)

Direct irritation of the gastric mucosa results in referred neural activation of bronchial glands, increased volume, and reduced viscosity of respiratory secretion (called gastropulmonary reflex action)

ADRs of guaifenesin (Robitussin)

Rare. Occasional GI irritation. 

Special Information of guaifenesin (Robitussin)

Hydration is very important with any expectorant (need enough fluid available so body can produce)

Classification of epinephrine

Sympathomimetic (non-selective), Bronchodilator

Action of epinephrine

Stimulates alpha, beta-1, beta-2 receptors

Alpha — mediates vasoconstriction to reduce mucosal edema

Beta-1— stimulates HR and force of contraction, as well as cardiac irritability

Beta-2 — induces bronchial smooth muscle relaxation

ADRs of epinephrine

nervousness, insomnia, fear, tremors, tachycardia, palpitations, headache

Special Information for epinephrine

Caution with CAD, HTN, and hyperthyroidism (↑ metabolic rate and cardiac sensitive) 

If you use MAO inhibitors concurrently (prevent breakdown; the body cannot get rid of), it will precipitate severe HTN (stroke or intracranial hemorrhage)

Classification of isoproterenol (Isuprel)

Sympathomimetic (non -selective Beta- stim. drug) bronchodilator

Action of isoproterenol (Isuprel)

Stimulates both beta-1 receptors (which stimulate the heart) and beta-2 receptors (which cause bronchodilation and decrease tone and motility of the GI and uterus)

ADRs of isoproterenol (Isuprel)

tachycardia and palpitation, headache, nausea, tremor, and insomnia. The more it is used, the less effective it may be

Special Information of isoproterenol (Isuprel)

Is one of the most powerful bronchodilators

Classification of albuterol (Proventil, Ventolin)

Bronchodilator, Sympathomimetic (selective- Beta2 stim)

Action of albuterol (Proventil, Ventolin)

beta-2 stimulation, causing relaxation of smooth muscle of the bronchial tree and the peripheral vasculature

ADRs albuterol (Proventil, Ventolin)

Few. Peripheral dilation can cause decreased blood pressure, which leads to tachycardia. Also tremors, nervousness, palpitations, dizziness, headache, N/V, anxiety, lethargy, tinnitus

Special Information for albuterol (Proventil, Ventolin)

An inhaled short-acting beta2 agonist, or “SABA”

Lasts longer than epinephrine, but onset slightly slower. Use with caution with diabetes, HTN, and cardiac disorders (esp. arrhythmias).

Long-acting beta-2 adrenergic receptor are called “LABAs”

Classification of ipratropium (Atrovent)

Anticholinergic Bronchodilator, an inhaled short-acting muscarinic antagonist (“SAAMA”)

Action of ipratropium (Atrovent)

Blocks cholinergic receptors, reducing bronchial tone. (Does not seem to affect volume or viscosity of sputum) → relaxes smooth muscle in the bronchial tree

ADRs of ipratropium (Atrovent)

Few. Dry mouth, pharyngeal irritation

Special Information for ipratropium (Atrovent)

1) Can be used in combination with albuterol

2) Used for maintenance therapy

Classification of aminophylline (theophylline)

Bronchodilator, Methylated xanthine

Action of aminophylline (theophylline)

Inhibits phosphodiesterase, which allows for increased cAMP— leads to relaxation of smooth muscle (esp. bronchial), stimulates the heart, stimulates CNS, and renal excretion. Stimulates medullary respiratory center

ADRs of aminophylline (theophylline)

GI – anorexia, N/V (probably due to stim. of vomiting center), abd. discomfort CNS – nervousness, insomnia, irritability, headache; severe convulsions and coma CV – tachycardia; severe – hypotension and arrhythmias Renal – urinary frequency

Special Information of aminophylline (theophylline)

1) Half-life in smokers is shorter than in non-smokers

2) Take with food to decrease GI irritability

Classification of cromolyn sodium (Intal)

Antiallergic (Histamine inhibitor)

Action of cromolyn sodium (Intal)

Inhibits release of histamine and other mediators of inflammation. Stabilizes cytoplasmic membrane of mast cells

ADRs of cromolyn sodium (Intal)

only common one is throat irritation

Special Information of cromolyn sodium (Intal)

1) Is used for asthma prophylaxis; has no use in acute attack!

2) Comes in metered dose inhaler (MDI), also powder-driven inhaler (turbo-inhaler). Is also a nasal spray (seasonal allergies), and in an ophthalmic solution (allergic eye disorders).

3) Teach to rinse mouth after inhalation treatment.

4) Especially effective for children (and minimal side effects)

5) Can prevent exercise-induced asthma attack (use 15 min. prior)

Classification of zafirlukast (Accolate)

Leukotriene receptor antagonist (LRA

Action of zafirlukast (Accolate)

Competes for leukotriene receptor sites – blocks inflammatory response (bronchoconstriction and inflammatory cell infiltration) caused by leukotrienes.

ADRs of zafirlukast (Accolate)

GI, headache, elevated liver function tests

Special Information of zafirlukast (Accolate)

1) Used as maintenance therapy of asthma. Prophylaxis only, not for reversal of bronchospasm in acute attack.

2) Concurrent administration with warfarin causes increased warfarin concentration and elevated PT. Administration with aspirin causes increased plasma levels of zafirlukast.

3) Take one hour before meals, or two hours afterward

Classification of beclomethasone (Vanceril)

Inhaled corticosteroid (“ICS”)

Action of beclomethasone (Vanceril)

Exact mechanism in asthma poorly understood, but does involve suppression of antibody formation. Blocks enzymes which produce inflammatory process in tissues. (In the Endocrine section, we will discuss systemic corticosteroids)

ADRs of beclomethasone (Vanceril)

Hoarseness, dry mouth, localized thrush infection

ADRs of beclomethasone (Vanceril)

1) Can have some absorption systemically, which then gives steroid response in body. Most effective long-term control treatment.

2) Teach client to rinse mouth after use.

3) Combination products: Advair (salmeterol and fluticasone) Dulera (formoterol and mometasone) Breo (vilanterol and fluticasone)

Classification of dextromethorphan (DM)

Antitussive, non-opioid

Action of dextromethorphan (DM)

Acts centrally to suppress the medullary cough center (elevates threshold for coughing. Has NO analgesic or addictive properties

Special Information of dextromethorphan (DM)

1) Is synthetic opiate derivative totally devoid of analgesic and respiratory depressant effects (except in overdose)

2) Many questions about effectiveness now.

3) Is designated “DM” when present with other non-prescription cough medicines.

Classification of pseudoephedrine (Sudafed)

Decongestant

Action of pseudoephedrine (Sudafed)

Stimulates both alpha and beta adrenergic receptors directly; also causes release of norepinephrine. Cardiac – vasoconstriction and cardiac stimulation (may increase BP) Respiratory – bronchial muscle relaxation is less prominent than epinephrine. Uterine – reduced activity CNS – acts as stimulant on cerebral cortex and medulla somewhat Vascular – Vasoconstriction (shrinks mucous membranes) but less than epinephrine

ADRs of pseudoephedrine (Sudafed)

Minimal, though CV = tachycardia, flushing

Special Information of pseudoephedrine (Sudafed)

Avoid taking near bedtime as stimulation can occur

Classification of diphenhydramine (Benadryl)

Antihistamine (H1-blocking drug)

Action of diphenhydramine (Benadryl)

A. competes with histamine for its receptor sites; thereby preventing physiologic action of histamine

1a) Smooth muscle response to histamine is inhibited. Histamine contracts many muscles (i.e. bronchi and GI) and relaxes others (fine blood vessels)

2a) Vascular – inhibits both vasoconstrictor effects of histamine and, to a degree, the more important vasodilator effects.

3a) Capillary permeability – strongly antagonizes action of histamine, this increases capillary permeability and formation of edema and weal.

4a) Does not inhibit histamine effect of stimulation of gastric secretion (involves H2 receptors)

B. inhibits release of acetylcholine

C. sedative

ADRs of diphenhydramine (Benadryl)

Rarely serious, and often disappear with continued therapy

CNS: *Sedation, dizziness, tinnitus, lassitude, blurred vision, diplopia, euphoria, nervousness, insomnia

GI: loss of appetite, N/V, epigastric distress constipation, diarrhea, dry mouth. Other – urinary frequency, palpitations, hypotension, headache, tingling and weakness of hands (may be caused by Atropine-like action of H1 blockers).

Allergic manifestations may occur – as dermatitis; more with topical application

Special Information of diphenhydramine (Benadryl)

1) Caution: Do not take concurrently with alcohol (it enhances the sedative effect).

2) Tolerance can occur.

3) Often used as hypnotic for children and adults