Exam 3 - Respiratory Drugs

Histamine

  • Chemical mediator that plays a role in the allergic response (along with others)

  • Actions:

    • Small vessel vasodilation

    • Increased capillary permeability

    • Bronchoconstriction

    • Sensory nerve stimulation

Allergic Rhinitis

  • Inflammatory disorder that affects the upper and lower airways and eyes

  • Treatment:

    • Antihistamines

    • Intranasal glucocorticoids

    • Sympathomimetic decongestants

    • Other—mast cell stabilizers, anticholinergics, leukotriene modifiers

Antihistamines “-ine”

  • Aka H1 Receptor antagonist relieves itching, sneezing, rhinorrhea (not congestion)

  • Generations:

    • Diphenhydramine (Benadryl – 1st)

    • Loratadine (Claritin – 2nd)

    • Azelastine (Astelin – 2nd generation, intranasal)

  • Use – mild allergy, motion sickness, insomnia

  • Adverse effects – sedation, nonsedative CNS effects – dizziness, fatigue, decreased coordination, anticholinergic effects, intranasal – headache, nosebleeds, unpleasant taste

  • All oral, some nasal and parenteral

  • **Not recommended for the common cold

Antihistamines— Patient Care

  • High risk - third trimester, nursing mothers

  • Caution: young children, elderly, patients with conditions aggravated by muscarinic blockade

  • Most effective when taken prophylactically – take throughout an allergy season – prevents histamine receptor activation

  • Sedative and anticholinergic effects more common with first generation than second

  • Sedative effects – caution driving, focused activities Nausea, vomiting – take with food

    • Don’t take with alcohol

    • Don’t crush or chew enteric coated preparations

In Summary

  • Histamine has a role in mild allergic symptoms (rhinitis, itching, local edema)

  • Mild allergic conditions respond well to antihistamines

  • Antihistamines are less effective than glucocorticoids for prevention and treatment of allergic rhinitis

  • DOES NOT play a major role in anaphylaxis (What is our drug of choice for anaphylaxis?)

Intranasal Glucocorticoids and Cromolyn

  • Intranasal Glucocorticoids

    • Fluticasone (Flonase – 2nd generation)

    • Anti-inflammatory Initial treatment of choice – reduce all symptoms

    • Adverse Effects – drying, burning, itching, sore throat, epistaxis, headache Intranasal

  • Intranasal Cromolyn

    • Cromolyn ( NasoCrom)

    • Stabilizes mast cells → suppresses release of inflammatory mediators

    • Prophylaxis – give before symptoms appear Adverse effects - minimal

Questions

  • Why should patients with glaucoma or BPH use first generation antihistamines with caution?

  • Name 4 anticholinergic effects that can occur when taking an antihistamine?

  • Which would be a better choice for allergic rhinitis – antihistamine or glucocorticoid

  • What is the action of cromolyn?

  • Sympathomimetics/ Decongestants

    • Uses – reduction of nasal congestion (allergic rhinitis, colds, sinusitis)

    • Action – stimulates alpha 1 receptors → vasoconstriction → shrinks swollen membranes (relieves stuffiness, congestion)

    • Examples: phenylephrine (Neo-synephrine) , pseudoephedrine (Sudafed)

    • Adverse effects: rebound congestion, CNS, caution in pts with cardiac disease

    • Administration: Topical (drops, sprays), oral

Sympathomimetics

  • PHENYLEPHRINE

    • Topicals

      • Act rapidly

      • Minimal systemic effects

      • Use no more than 5 days

      • Rebound congestion likely

  • PSEUDOEPHEDRINE

    • Orals

      • Act more slowly

      • More likely to have systemic effects

      • Cardiac and CNS effects more likely

Combat Methamphetamine

  • Epidemic Act - 2005

  • Abuse potential – amphetamine-like effects

  • Products with ephedrine and pseudoephedrine behind a counter Purchases limited—ID and signature required

  • Many products reformulated to contain phenylephrine


Other Respiratory

  • Antitussives - Cough

    • Opioids: Codeine

    • Non-opioids: Dextromethorphan (Robitussin), benzonatate (Tessalon)

  • Expectorants & Mucolytics

    • Guaifenesin (Mucinex) – expectorant – stimulates flow of respiratory secretions – increases/thins mucous

    • Acetylcysteine [acetaminophen reverse medication] (Mucomyst), hypertonic saline – mucolytics –direct action on mucous to make more watery.

Questions

  • What adrenergic receptor is activated by pseudoephedrine?

    • Alpha 1

  • Why should clients with hypertension and cardiac disorders avoid sympathomimetics?

    • Can cause vasoconstriction

  • Which form of cough medication when taken as prescribed can have the adverse effect of suppressing respirations?

  • To avoid adverse effects, what advice should the nurse give to a client taking oral benzonatate?

Pharmacological Therapy: Combos

  • Nasal decongestant

  • Antitussive

  • Analgesic

  • Antihistamine

  • Caffeine

OTC Cold Remedies— Safety in Children

  • Recommendations:

    • should not be used for infants and children under 4-6

    • Use only products labeled for peds use

    • Consult a healthcare professional before giving to a child

    • READ all product safety information

    • Use measuring device provided by product

    • If condition worsens or doesn’t improve – discontinue use of med and consult provider

    • Don’t use antihistamine products for sedation

Drugs for Asthma and COPD

  • Anti–inflammatory

    • Glucocorticoids – beclomethasone , budesonide (inhaled), prednisone (oral), methylpredisolone

    • Others – Cromolyn, leukotriene modifiers

  • Bronchodilators

    • Beta 2 agonists – albuterol (inhaled, short acting), salmeterol (inhaled, long acting)

    • Methylxanthines – theophylline (Elixophyllin)

    • Anticholinergic – ipratropium (Atrovent)

Types of Devices Used to Deliver Inhalation

  • Meds Metered dose inhalers (MDI) – with or without spacers

  • Dry powder inhalers (DPI)

  • Respimat

  • Jet nebulizers

  • Most drugs given by inhalation - increases therapeutic effects, reduces systemic effects, rapid relief

Inhalation Devices

  • Asthma Treatment Approach

    • Reduce impairment

      • Reduce chronic and troublesome symptoms (coughing, shortness of breath )

      • Reduce use of short acting beta agonists (SABA) for symptom relief to 2 days a week or less

      • Maintain pulmonary function

      • Maintain normal activity levels

    • Reduce risk

      • Prevent exacerbations

      • Reduce ER visits, hospitalizations

      • Maximum benefit - minimize drug side effects

      • Prevent progressive loss of lung function

  • Accomplished through reduction of triggers, meds for quick relief (SABA) and long-term control (Anti-inflammatories, SABA)

COPD Management

  • Four classifications of COPD

    • Mild - group A – few symptoms, low risk

    • Moderate - group B – increased symp., low risk

    • Severe - group C – few symptoms, high risk

    • Very severe - group D – increased symp., high risk

  • Goals

    • Reduce symptoms

      • Improve health status

      • Increase exercise tolerance

    • Reduce risks and mortality

      • Prevent disease progression

      • Prevent and manage exacerbations

  • Accomplished through use of bronchodilators (LABA – control, SABA exacerbations), glucocorticoids and other drugs

Anti-Inflammatory: Glucocorticoids

  • Suppress inflammation

    • Decrease synthesis and release of inflammatory mediators

    • Decrease infiltration, activity of inflammatory cells

    • Decrease edema of the airway mucosa

  • Decrease airway mucus production

  • Increase number of beta 2 receptors

  • Oral/inhalation – can be given IV

  • Not used to abort an ongoing attack, given on a fixed schedule, not prn.

Anti-inflammatory: Glucocorticoids

  • Inhaled

    • Beclomethasone (Vanceril) – MDI

    • Budesonide (Pulmicort) – DPI

    • Fluticasone (Flovent) - MDI

  • Oral

    • Prednisone (Deltasone)

  • IV

    • Methylprednisolone (Solu-medrol)

Glucocorticoid Adverse Effects

  • Inhaled → dysphonia, oropharyngeal candidiasis, bone loss (long-term use), slows growth rate in children

  • Long term, high dose oral → adrenal suppression, osteoporosis, hyperglycemia, peptic ulcer disease, growth suppression in young

  • If taking oral, long-term glucocorticoids –during stress may need to give oral/IV supplements due to adrenal suppression

Patient Care: Anti-inflammatory Glucocorticoids

  • Inhaled – gargle after use to reduce dysphonia, candidiasis

  • Patient education

    • Teach use of MDI, DPI and spacers

    • Adequate calcium, vitamin D, weightbearing exercises to reduce bone loss

    • Educate about adverse effects

    • Not used to abort an acute exacerbation

Anti-inflammatory: Leukotriene Modifiers

  • Leukotrienes – inflammatory mediators, promote bronchoconstriction, increase capillary permeability and promote other inflammatory cell actions.

  • Modifying response: reduces inflammatory response, prevents bronchoconstriction and eosinophil infiltration, reduces mucus production and edema

  • Maintenance (long-term) therapy, not quick relief

  • Drugs – Zafirlukast (Accolate), montelukast (Singulair), Zileuton (Zyflo)

  • Oral administration

  • Adverse effects: Zileuton – liver injury, dyspepsia, zafirukast – liver injury, GI disturbance, headache, montelukast – no liver injury

Anti-inflammatory: Cromolyn (Intal)

  • Suppress bronchial inflammation

    • Stabilizes cytoplasmic membrane of mast cells → suppresses release of inflammatory mediators Use only for prophylaxis – not acute problem

  • Must be taken before allergen exposure

  • Route: inhalation, fixed schedule

  • Safe, few adverse effects

Questions

  • What are three examples of drugs used to treat inflammation in patients with asthma?

  • A patient has been on long-term oral glucocorticoid therapy. Oral administration is changed to inhaled.

  • Why should long term glucocorticoid therapy not be abruptly stopped?

    • Why might supplemental glucocorticoids be needed?

      • increased stress, infections

    • Which anti-inflammatory acts by stabilizing mast cells?

      • chromolyn

  • Anti-inflammatory drugs to prevent asthma or COPD exacerbations are taken on what schedule (fixed or prn)?

    • fixed schedule

Bronchodilation — Beta 2 Adrenergic Agonist (respiratory effects)

  • Drugs:

    • albuterol (Proventil) - short-acting, inhaled, oral

    • salmeterol (Serevent) - long acting inhaled, terbutaline

    • (Brethine) - oral

  • Action

    • Activate Beta 2 receptors in smooth muscle

    • Bronchodilation → relieve of bronchospasm

    • Block release of histamine in lung

    • Increase ciliary motility

  • Use – acute bronchospasm

  • Route – inhaled, oral

  • Types

    • Inhaled short acting – prn relief, “rescue inhaler”

    • Inhaled long acting – long term control, not first line, not used alone

    • Oral – long term control, not first line, not used alone

Bronchodilation: Beta 2 Adrenergic Agonist

  • Adverse effects:

    • Short acting – tachycardia, angina, tremor

    • Long acting – increase risk of severe asthma and asthma-related death

    • Oral – beta 1 effects – angina, tachycardia, beta 2 effects on skeletal muscle - tremor

    • SA- albuterol (ProAir HFA), LA – salmeterol (Serevent), Oral –terbutaline (Brethine)

Questions

  • What two classes of drugs are most frequently used in the control of asthma?

  • What is the advantage of administering medications via inhalation, rather than oral or parenteral?

  • Can glucocorticoids be used to abort an ongoing asthma or COPD exacerbation?

  • How does a beta 2 agonist relieve symptoms of an acute exacerbation?

Bronchodilators — Actions

  • ANTICHOLINERGICS

    • Blocks muscarinic cholinergic receptors in bronchi

    • Promotes bronchodilation

    • Ipratropium (Atrovent) - inhaled

  • METHYLXANTHINES

    • Bronchodilation – exact mechanism uncertain

    • Narrow therapeutic range – 5-15 mcg/ml

    • >30 mcg/ml - seizures, dysrhythmias

    • Theophylline (Elixophyllin) – oral or IV

    • Avoid use with caffeine

Summary — Bronchodilators

  • Beta2-Adrenergic Agonists

    • Inhaled: short-acting albuterol (proventil)

    • Inhaled: long-acting salmeterol (Serevent)

    • Oral

      • albuterol (Proventil)

      • terbutaline(Brethine)

    • Methylxanthines

      • Theophylline

    • Anticholinergics

      • Ipratropium (Atrovent)

Questions

  • What is a non-pharmacologic treatment for asthma resulting from allergies?

  • What is the treatment for an acute asthma exacerbation?

  • A client uses a rescue inhaler consistently more than twice a week, what might be needed?

  • What is the treatment for a patient with stable COPD? Severe chronic COPD? COPD exacerbation?