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8/3/2019 Resp Pharma

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RESPIRATORY

PHARMACOLOGY


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Respiratory Pharmacology

GENERIC: Albuterol

BRAND: Proventil, Ventolin

CLASS: Sympathomimetic


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Albuterol

Actions

1. Agonist for Beta 2 adrenergic receptors; relaxingbronchial smooth muscle which results in

bronchodilation

2. Minimal cardiac side effects


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Albuterol

Indications:

1. Treatment of bronchospasm associated with asthma,chronic bronchitis and emphysema

2. Prevention of exercise-induced bronchospasm


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Albuterol

Contraindications:

1. Hypersensitivity to sympathomimetics

2. Cardiac dysrhythmia

3. Tachycardia and tachydysrhythmias


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Albuterol

Adverse Reactions:

1. Excessive use may cause paradoxical bronchospasmand arrhythmias

2. Tachycardia, palpitations, angina, PVCs, hypotension,and hypertension

3. Tremors

4. Hyperglycemia

5. Peripheral vasodilation6. Nervousness

7. Nausea/Vomiting


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Albuterol

Precautions:

1. Diabetes

2. Hyperthyroidism

3. Cerebrovascular disease

4. Seizure disorders


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Albuterol

Dose:

1. 2 inhalations with metered-dose inhaler, q 4-6 hours

2. 3 ml premixed bullet in nebulizer


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Albuterol

Incompatible/Reactions:

1. Tricyclic antidepressants/monoamine oxidaseinhibitors (MAOIs), may increase the effect of this drug

2. Other sympathomimetics3. Beta blockers inhibit the effects


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Albuterol

Notes:

Onset: 5-15 minutes

Peak: 30 minutes 2 hoursDuration: 3-4 hours

1. Can be delivered by inhaler and nebulizer

2. Metabolized in the liver and excreted in the urine


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GENERIC: Epinephrine

BRAND: Adrenalin

CLASS:Sympathomimetic/Catecholamine


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Epinephrine

Action:

1. Direct effect on alphaand betaadrenergic receptorsites

2. Effects include:Alpha: bronchial, cutaneous, renal and visceralarteriolar constriction

Beta 1: positive inotropic and chronotropic actions,

increases automaticityBeta 2: bronchial smooth muscle relaxation anddilation of skeletal vasculature

3. Inhibits the release of histamine


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Epinephrine

Indications:

1. Cardiac arrest in general

2. Ventricular fibrillation

3. Asystole4. Pulseless electrical activity

5. Infusion for profound hypotension associated withbradycardias, in combination with other pressors

6. Bronchospasm and bronchoconstriction of bronchialasthma and some forms of COPD

7. Anaphylaxis


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Epinephrine

Contraindications:

1. Uncorrected tachydysrhythmias

2. Underlying cardiovascular disease or hypertension3. Glaucoma

4. Hypersensitivity to catecholamines

5. Hypothermia


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Epinephrine/Adverse Reactions

Hypertension

Ventricular arrhythmias

Pulmonary edema

TachycardiaPalpitations

Anxiety

Psychomotor agitation

Nausea/Vomiting

Pupil dilation

Angina

Nervousness

Headache

Dizziness

TremorsHallucinations

Cerebral hemorrhage

Anorexia


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Epinephrine

Precautions:

1. Due to the possibility of cardiovascular disease,epinephrine should be administered with caution in

patients over 35 years of age (with respiratoryproblems or if they are conscious)

2. The patient should be carefully monitored for changesin pulse, blood pressure, and ECG after administrationof epinephrine.

3. Because of its strong inotropic and chronotropiceffects, epinephrine causes an increased myocardialO2 demand


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Epinephrine

Precautions:

4. Hypovolemia (replenish volume first)

5. Diabetes mellitus

6. Hyperthyroidism7. Prostatic hypertrophy

8. Must be protected from light

9. Tends to be deactivated by alkaline solutions (sodium

bicarbonate)

10. Do not use with MAOIs or tricyclic antidepressants dueto the danger of hypertensive crisis


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Epinephrine

Dose:

1. Cardiac dosage: 1:10,000

a. 1 mg q 3-5 minutes (until the heart restarts)

b. Intermediate: 2-5 mg q 3-5 minutesc. Escalating: 1 mg 3 mg 5 mg; 3 minutes apart

d. High: 0.1 mg/kg q 3-5 minutes

2. Infusion: Mix 1 mg in 250 ml and run at 2-10 mcg/min

3. Anaphylaxis and Asthma: .1-.5 mg (1:1,000) SQ or IM


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Epinephrine

Incompatible/Reactions:1. Potentiates other sympathomimetics

2. Patients on MAOIs, antihistamines, and tricyclicantidepressants may have heightened effects

3. Sodium bicarbonate deactivates epinephrine

4. Nitrates

5. Lidocaine

6. Aminophylline

7. Dont mix the above drugs in the same syringe withepi; but can use in the same IV line just flushbetween meds


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Epinephrine

Notes:

ONSET: Immediate

PEAK: Minutes

DURATION: Several minutes


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GENERIC: Isoetharine

BRAND: Bronkosol, Bronkometer



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Isoetharine

Actions:

1. Beta 2 agonist (slight specificity); relaxes smooth

muscle of bronchioles, vasculature, uterus


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Isoetharine

Indications:

1. Relieve bronchospasm associated with asthma, chronic

bronchitis, and emphysema


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Isoetharine

Contraindications:


2. Cardiac dysrhythmias3. Tachycardia and tachydysrhythmias


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Isoetharine

Adverse Reactions:

1. Dose-related tachycardia, palpitations, tremors,nervousness, peripheral vasodilation, nausea/vomiting,transient hyperglycemia, life-threatening arrhythmias;multiple excessive doses can cause paradoxicalbronchoconstriction

2. Angina

3. Hypertension

4. Headache, dizziness, anxiety, restlessness,hallucinations


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Isoetharine

Precautions:

1. Use with caution in patients with diabetes,hyperthyroidism, cardiovascular and cerebrovasculardisease

2. Seizure disorders

3. Isoetharine contains acetone sodium bisulfite; a sulfitethat may cause allergic-type reactions, includinganaphylactic symptoms in certain susceptibleindividuals


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Isoetharine

Dose:

ADULT

1-2 inhalations with metered-dose inhaler3-7 inhalations, via hand nebulizer q 4 hours

PEDIATRIC

Not recommended in children less than 12 years


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Isoetharine


1. Additive adverse effects with other beta agonists


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Isoetharine

Notes:

ONSET: Immediate

PEAK: 5-15 minutes

DURATION: 1-4 hours


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GENERIC: Metaproterenol Sulfate

BRAND: Alupent, Metaprel



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Metaproterenol Sulfate

Actions:

1. Agonist for Beta 2 adrenergic receptors acts directly

on smooth muscle


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Indications:

1. Relieve bronchospasm of COPD and Asthma


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Contraindications:


2. Hyperthyroidism3. Cerebrovascular or cardiovascular disorders

4. Tachycardia and tachydysrhythmias


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Metaproterenol SulfateAdverse Reactions

Dose-related tachycardia

Palpitations

Nervousness

Peripheral vasodilationExcessive use lethalarrhythmias, paradoxicalbronchospasm

Hypertension

Tremors, headache,dizziness, anxiety,hallucinations

Nausea/vomiting


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Precautions:

1. History of cardiovascular disease or hypertension

2. Seizures


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Dose:

ADULT:

2-3 inhalations, q 3-4 hoursMetered-dose inhaler or nebulizer

PEDIATRICS:

Not recommended in children under 12 years


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1. Beta blockers

2. MAOIs, tricyclic antidepressants3. Potentiates other beta agonists


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Notes:

ONSET: 1 minute

PEAK: 1 hour

DURATION: 1-5 hours with single dose

2-5 hours with repeated dose


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GENERIC: Terbutaline Sulfate

BRAND: Bricanyl, Brethine



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Terbutaline Sulfate

Actions:

1. Beta 2 agonist has an affinity for beta 2 receptors of

bronchial, vascular, and uterine smooth muscle

2. At increased doses, beta 1 effects may occur


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Terbutaline Sulfate

Indications:

1. Relieve bronchospasm associated with asthma,

chronic bronchitis and emphysema (prevalent inpatients over the age of 40 or with coronary arterydisease)

2. Used in-hospital to stop pre-term labor


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Terbutaline Sulfate

Contraindications:



4. Glaucoma


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Terbutaline Sulfate

Adverse Reactions:

1. Tachycardia, tremors, palpitations, nervousness and

dizziness2. Angina, PVCs, hypotension, and hypertension

3. Headache, anxiety, hallucinations

4. Nausea, vomiting

5. Bronchospasm


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Terbutaline Sulfate

Precautions:

1. Used with caution to patients with a history of

cardiovascular disease or hypertension2. Seizure disorders

3. Thyroid disease

4. Diabetes


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Terbutaline Sulfate

Dose:

ADULT:

0.25 mg SQ; repeat in 15-20 minutes2 inhalations separated by a 60 second interval with a

metered dose inhaler

4mg/7ml nebulizer mix


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Terbutaline Sulfate


1. Alkaline solutions

2. Degrades when exposed to light for long periods oftime


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Terbutaline Sulfate

Notes:

ONSET: 15 minutes

PEAK: 30-60 minutes

DURATION: 90 minutes 4 hours


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GENERIC: Theophylline Ethylenediamine

BRAND: Aminophylline

CLASS: Methylxanthine Spasmolytic


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Theophylline

Actions:

1. Beta 2 agonist; directly relaxes bronchial smoothmuscle

2. Dilates pulmonary and coronary arterioles, decreasingpulmonary hypertension and increasing coronary bloodflow

3. Slight positive chronotropic and inotropic effects

4. Strengthens diaphragmatic contractions by affectingintracellular calcium

5. Mild diuretic


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Theophylline

Actions:

6. Stimulates CNS vomiting centers

7. Respiratory center stimulant

8. Stimulates vagal and vasomotor centers in the braincan lead to decreased heart rate, vasoconstriction inthe brain depends on CNS or peripheralpredominance


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Theophylline

Indications:

1. Relieve bronchospasm associated with asthma,

chronic bronchitis, emphysema, and pulmonary edema2. Management of CHF and pulmonary edema


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Theophylline

Contraindications:

1. Hypersensitivity to xanthene compounds (e.g. caffeine)


Theophylline


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TheophyllineAdverse Reactions

Nausea/vomiting

Hypotension

Irritability

TachycardiaAngina

Flushing

Diarrhea

Increased respiratory rateCardiac arrhythmias

Tremors

Seizures

Palpitations

HypertensionAnorexia


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Theophylline

Precautions:

1. Caution if patient is already taking theophylline-containing medications

2. Caution to patients with a history of cardiovasculardisease or hypertension

3. Thyroid disease

4. Active peptic ulcer

5. Hypotension may occur following rapid administration6. May oppose the effects of beta blockers


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Theophylline

Dose:

ADULT:

Loading dose of 6 mg/kg IV infusion over 20 minutesLoading dose of 1 mg/kg IV infusion over 20 minutes if the

patient has had theophylline products in the last 35hours


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Theophylline


1. Incompatible with most drugs

2. Simetidine, propranolol, erythromycin, andtroleandomycin may increase the effects of the drug

3. Barbiturates, phenytoin, and smoking may decreaseblood levels

4. May increase the effects of anticoagulants


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Theophylline

Notes:ONSET: 15 minutes:

PEAK: 30 minutes 1 hour

DURATION: Averages 5 hours

1. Common forms or oral aminophylline include:

* Marax * Primatene

* Quibron * Slo-Phyllin

* Slobid * Somophyllin

* Tedral * Theo-Dur


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Respiratory meds are used for severalpurposes, the most obvious is the treatment ofasthma.

Class includes:1. Cough suppressants

2. Nasal decongestants

3. Antihistamines


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Antiasthmatic Medications

Asthma has two basic pathophysiologies:1. Bronchoconstriction

2. Inflammation

Treatment is aimed to relieve bronchospasmand decrease inflammation.

Specific approaches are categorized as beta 2selective sympathomimetics, nonselectivesympathomimetics, methylxanthines,anticholinergics, glucocorticoids andleukotriene antagonists.


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Beta 2 Specific Agents

Albuterol (Proventil, Ventolin) is the prototype of thisclass.

1. These agents relax bronchial smooth muscle, resultingin bronchodilation and relief from bronchospasm.

2. These agents are first line therapy for acute shortnessof breath.

3. Administered via metered dose inhaler or nebulizer.

4. Overall, these agents are very safe.

Nonselective


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NonselectiveSympathomimetics

Stimulate both beta 1 and beta 2 receptors, as well asalpha receptors.

Rarely used to treat asthma because they have theundesired effects of increased peripheral vascular

resistance and increased risks for tachycardias andother dysrhythmias.

Agents include: epinephrine, ephedrine, andisoproterenol

Epinephrine is the only nonselective sympathomimetic incommon use today.


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Methylxanthines

CNS stimulants that have additional bronchodilatoryproperties.

Used only when other drugs such as beta 2 specificagents are ineffective.

Possibly block adenosine receptors.

Prototype is theophylline, taken orally.

Aminophylline, an IV medication, is rapidly metabolizedinto theophylline and, therefore, has identical effects.

Chief side effects: nausea/vomiting, insomnia,restlessness, and dysrhythmias


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Anticholinergics

Ipratropium (Atrovent) is an atropine derivative given bynebulizer.

Because stimulating the muscarinic receptors in thelungs results in constriction of bronchial smooth muscle,

ipratropium, a muscarinic antagonist, causesbronchodilation.

Ipratropium is inhaled, and has no systemic effects.

Has an additive effect when used with beta 2 agonists.

Most common side effect is dry mouth


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Glucocorticoids

Anti-inflammatory properties.

Lower the production and release of inflammatorysubstances such as histamine, prostaglandins, andleukotrienes, and reduce mucus and edema secondary

to decreasing vascular permeability.May be inhaled or taken orally, as well as IV.

Prototype of inhaled glucocorticoid is beclomethasone.

Prototype of oral glucocorticoid is prednisone.

Administered as preventative care.


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Glucocorticoids

When inhaled they cause few side effects.

Side effects are due mostly to direct exposure on theoropharynx, and gargling after taking the drug candecrease the side effects.

Side effects from the IV administrations ofmethylprednisolone in emergencies are not likely

Long periods of administration can lead to adrenalsuppression and hyperglycemia.

Another anti-inflammatory agent used is cromolyn (Intal),an inhaled powder.


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Glucocorticoids

Cromolyn is the safest of all antiasthma agents.

Only side effects are coughing or wheezing due to localirritation caused by the powder.

Often used for preventing asthma in adults and children.


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Leukotriene Antagonists

Leukotrienes are mediators released from mast cellsupon contact with allergens.

Contribute powerfully to both inflammation andbronchoconstriction

Can either block the synthesis of leukotrienes or blocktheir receptors.

Zileuton (Zyflo) is the prototype of those that block thesynthesis of leukotrienes

Zafirlukast (Accolate) is the prototype of those that blocktheir receptors

DRUGS USED FOR RHINITIS


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DRUGS USED FOR RHINITISAND COUGH

Rhinitis: (inflammation of the nasal lining)comprises a group of symptoms including nasalcongestion, itching, redness, sneezing, andrhinorrhea (runny nose).

Allergic reactions or viral infections may cause it

Drugs that treat the symptoms of rhinitis andcold are commonly found in over-the-counterremedies.

Nasal decongestants, antihistamines, and coughsuppressants are available in prescriptionmedications.


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Nasal Decongestants

Nasal congestion is caused by dilated and engorgednasal capillaries.

Drugs that constrict these capillaries are effective nasaldecongestants.

Main pharmacologic classification in this functionalcategory is alpha 1 agonists

Alpha 1 agonists may be given either topically or orally

Examples of agents: phenylephrine, pseudoephedrine,

and phenylpropanolamine, (administered in drops ormist)


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Antihistamines

Arrest the effects of histamine by blocking its receptors.

Histamineis an endogenous substance that affects awide variety of organs systems.

Noted for its role in allergic reaction.

Histamine binds with H1 receptors to cause vasodilationand increased capillary permeability (vasculature)

In the lungs, H1 receptors cause bronchoconstriction

In the gut, H2 receptors cause an increase in gastric acidrelease

Histamine also acts as a neurotransmitter in the CNS.


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Antihistamines

Histamine is synthesized and stored in two types ofgranulocytes; tissue-bound mast cells and plasma-bound basophils

Both types are full of secretory granules, which are

vesicles containing inflammatory mediators such ashistamine, leukotrienes, and prostaglandins, amongothers.

When cells are exposed to allergens, they develop

antibodies on their surfaces.On subsequent exposures, the antibodies bind with theirspecific allergen.


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Antihistamines

Secretory granules then migrate towards the cellsexterior and fuse with the cell membrane. Causing themto release their contents.

Histamines are useful in our immune systems.

When our immune systems overreact do allergies suchas hay fever or cedar fever send us running for theantihistamines

Typical symptoms of allergic reaction include most of

those associated with rhinitis.Severe allergic reactions (anaphylaxis) may causehypotension


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Antihistamines

Antihistamines are at best only a secondary drug fortreating anaphylaxis.

Just as there are H1 and H2 histamine receptors, thereare H1 and H2 histamine receptor antagonists.

Most old antihistamines were H1 receptor antagonists,newer antihistamines are H2 receptor antagonists.

Chief side effect is sedation (H1), newer generation donot cause this sedation effect (H2).

First generation medications: alkylamines(chlorpheniramine [Chlor-Trimeton]), ethanolamines(diphenhydramine [Benadryl])


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Antihistamines

Other first generation antihistamines: clemastine(Tavist), and phenothiazines (promethazine[Phenergan]).

Some antihistamines also have significant anticholinergic

properties: promethazine and dimenhydrinate(Dramamine), used for motion sickness.

Second generation antihistamines include: terfenadine(Seldane), loratadine (Claritine), cetirizine (Zyrtec, and

fexofenadine (Allegra).These agents do not cross the blood-brain barrier andtherefore do not cause sedation.


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Cough Suppressants

Coughing is a complex reflex that depends on functionsin the CNS, the PNS, and the respiratory muscles.

It is a defense mechanism that aids the removal offoreign particles like smoke and dust.

In general, treating a productive cough is notappropriate, as it is performing a useful function.

An unproductive cough, usually results from an irritatedoropharynx and can be troublesome.

The three classifications of cough suppressants includeone that is supported by evidence and two that are not.


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Cough Suppressants

Antitussives1. Suppress the stimulus to cough in the CNS.

2. This functional class includes two specificpharmacologic types:

a. Opioids

b. Nonopioids

3. Two most common opioid antitussives are codeine and

hydrocodone4. Both inhibit the stimulus for coughing in the brain but

also produce varying degrees of euphoria

C S


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Cough Suppressants

5. The nonopioid antitussives do not have the potentialfor abuse.

a. Dextromethoraphan

b. Diphenhydramine

c. Benzonatate (Tessalon)Expectorants: intended to increase the productivity ofcough

Mucolytics:make mucus more watery and easier to

cough upLittle data supports the effectiveness of either of theseapproaches to cough suppression

Resp Pharma

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