Ch. 17 Drugs for the Treatment of Respiratory Disorders and Allergic Rhinitis
What are the LTs produced by?
Cells of inflammation and produce + Bronchoconstriction + Increased mucus secretion + Mucosal edema, Greater bronchial hyperreactivity
What drugs having ozone-depleting properties, have been phased out as propellants in MDIs?
Chlorofluorocarbons (CFCs)
***What is Chronic bronchitis a result of?
Chronic inflammation of the airways and excessive sputum production
H1-RECEPTOR BLOCKING EFFECTS
Competitively block or antagonize histamine's of the following sites • Capillary permeability • Vascular smooth muscle (vessels) • Nonvascular (bronchial) smooth muscle • Cutaneous nerve endings
Which agents produce no immediate benefit in an acute asthmatic attack but they hasten recovery and decrease morbidity and reduce airway hyperreactivity in theses pts ?
Corticosteroids
What drug can be used prophylactically be pt. with chronic asthma or taken before exercise-induced asthma?
Cromolyn
What is the least toxic of all asthma medications?
Cromolyn
Which agents is effective only for the prophylaxis of asthma and not for treatment of an acute attack?
Cromolyn (Intal, Nasalcrom)
What inhibits mast cell degranulation and is a mediator release when given before allergen exposure?
Cromolyn sodium
What is a pt's ventilation driven by if they have COPD?
Decrease in Pao2 (partial pressure of oxygen) + if oxygen is administered the Pao2 rises, the stimulant to breathing is removed, and apnea may be induced
An opioid-like compound, suppresses the cough reflex through its direct effect on the cough center
Dextromethorphan (the DM in cough medicines such as Robitussin DM)
RESPIRATORY DRUGS IN THIS CHAPTER
Drugs that increase + Expectoration (ejecting saliva) + Reduce coughs
What is the most effective method of treating allergic rhinitis?
Eliminate the source of allergen. If this is not possible, medication is necessary
What are LTs synthesized by?
Enzyme 5-lipozygenase from arachidonic acid, which also produces prostaglandins (PGs)
What is the drug of choice if an allergic reaction is severe?
Epinephrine
What can increase the serum levels of theophylline, leading to toxicity?
Erythromycin
Which generation of H1- antihistamines can cause anticholinergic effects such as xerostomia?
First-generation H1 antihistamines
What do pts. with COPD experience in regards to Paco2 over time?
Gradual rise in Paco2
What are the first-generation H1 antihistamines, also called?
H1- blockers
How are long-acting B2 agonists best administered?
In a fixed-dose combination in the same inhaler with an inhaled corticosteroid
ANTICHOLINERGIC EFFECTS
In pts. taking antihistamines long term, the mouth should be observed for symptoms of xerostomia and counseling about techniques to manage it should be presented.
What agents are the most effective long-term treatment option for control of symptoms in all pts. with mild, moderate, or severe persistent asthma?
Inhaled corticosteroids
Are very effective for the treatment of moderate to severe allergic rhinitis and are considered firs-line therapy
Intranasal corticosteroids
Is a short-acting antimuscarinic available for oral inhaltion for people with COPD
Ipratropium bromide (Atrovent)
What is COPD characterized by?
Irreversible airway obstruction which occurs with either + Chronic bronchitis + Emphysema
What is the advantage of cromolyn?
Its safety
Is usually used as an adjunct therapy with H1 antihistamines and intranasal corticosteroids
LTRA montelukast (singulair)
What agent is less effective than H1 histamines and intranasal corticosteroids?
LTRA montelukast (singulair)
What is is approved for the treatment of seasonal and perennial allergic rhinitis
LTRA montelukast (singulair) and provides: - Relief for sneezing, itching, discharge and congestion
What agents are used to manage pts with asthma that is not controlled by B2-agonists and corticosteroid inhaler?
Leukotriene modifiers (LTs)
ADVERSE REACTIONS
Like the pharmacologic effect of the antihistamines the adverse reactions vary among the different agents
What is used to treat pts with persistent asthma that is not well-controlled by low-dose inhaled corticosteroid alone
Long-acting B2-agonist inhaler in conjunction with low-dose inhaled corticosteroid
Maintenance treatment with what agents can benefit pts with COPD who have moderate to severe airflow obstruction and chronic symptoms?
Long-acting B2-agonists
What combination of drugs are used to treat persistent asthma so that two different drugs, at lower doses can be used and thereby improving adherence to therapy ?
Long-acting B2-agonists and corticosteroid inhalers
What drug is a heavily advertised nonsedating antihistamine?
Loratadine (Claritin)
First in a new class of drugs approved by the FDA to treat severe asthma in pts. with elevated eosinophil level
Mepolizumab (Nucala) and relisumab (Cinqair)
What are long-acting B2-agonists not recommended for in asthma?
Monotherapy for asthma
Leukotriene Modifier
Montelukast (Singulair)
What agent is similar in action to cormolyn?
Nedocromil (Tilade)
What do pts often complain about when taking methylxanthines?
Nervousness and insomnia
Which agent has replaced Chlorofluorocarbons (CFCs) in propellants in MDIs, because it does not deplete the ozone layer?
Nonchlorinated hydrofluoroalkane propellants
Which antihistamine drugs produce less sedation ?
Nonsedating H1-blockers because they do not penetrate the brain easily + Loratadine (Claritin)
What type of antihistamines have much less anticholingeric effects and are less likely to cause xerostomia?
Nonsedating antihistamines
A recombinant humanized monoclonal antibody that prevents IgE from binding to mast cells and basophils, thereby preventing the release of inflammatory mediators after allergen exposure
Omalizumab (xolair)
Is the frist in a new class of medications introduced to treat asthma due to allergens
Omalizumab (xolair)
What should pts who are given first-generation antihistamines be warned against?
Operating a mother vehicle or signing important documents
What is seasonal rhinitis usually caused by?
Pollen from trees, grass, and flowers
Who should theophylline be limited to?
Pts. whose asthma or COPD is not controlled with other agents
What do pts taking corticosteroids have a significant improvement in?
Pulmonary function, with a decrease in wheezing, tightness, and cough
What are the orally inhaled corticosteroid especially useful in?
Reducing inflammation and therefore the secretions and swelling that occurs within the lungs after an asthma attack occurs
What are other respiratory problems related to?
Respiratory infections, principally viral or bacterial
What should pts using oral corticosteroid inhalers be advised to do?
Rinse the mouth and gargle with water after using inhaler to minimize the chance of candidiasis
What is the most common side effect associated with the first generation antihistamines?
Sedation, and it may be accompanied by + Dizziness + Tinnitus + Incoordination + Blurred vision + Fatigue
What causes perennial allergic rhinitis?
Sensitivity to different allergens such as + house dust and animal dander
How long does season rhinitis last?
Several weeks to months
What drugs have studies shown that the overuse of these agents result in airway hyperresponsiveness and a decrease in the lung's response to them?
Short-Acting B2-agonists
What agents is the first line of treatment for intermittent asthma?
Short-acting B2-agonist
What are the drugs of choice for the emergency treatment of an acute attack of asthma?
Short-acting B2-agonists
Signs of an acute asthmatic attack
Shortness of breath and wheezing
What pts have persistent life-threatening bronchospasm despite drug therapy?
Status asthmaticus
What properties of codeine-containing cough preparations may precipitate bronchospasm?
Their histamine-releasing properties
How long does perennial allergic rhinitis last?
Throughout the year
An inhaled long-acting antimuscarinic drug used to treat COPD
Tiotropium bromide (Spiriva)
How are many drugs used to treat respiratory problems administerd?
Topically via the lungs by the use of a metered-dose inhaler (MDI)
How often should long-acting B2-agonists be administered?
Twice a day with the exception of indacaterol (once-daily dosing)
what does inhaled antimuscarinic drugs appear to inhibit?
Vagally mediated reflexes by antagonizing the action of acetylcholine, thereby causing bronchodilation
SIDE EFFECTS OF CORTICOSTEROIDS: ASTHMA
Vary depending on: + Route of administration + Frequency of intake + Duration of intake + Total dose + Preexisting diseases
When is theophylline often omitted from an asthmatic pt.'s therapeutic regimen?
When the chance of theophylline toxicity is weighted against the potential therapeutic benefit
Respiratory drug group range
Wider range from + Adrenergic drugs for bronchodilation to + Corticosteroids for reducing inflammation
What is associated with almost all cases of COPD?
smoking
How is omalizumab administered?
subcutaneous injection every 2-4 weeks
Are disease of the respiratory tract common?
yes, so dental hygienist are sure to encounter pts. taking drugs for these disease
CORTICOSTEROIDS: COPD
***- Inhaled corticosteroid monotherapy in not approved for COPD. ***- Inhaled corticosteroid in combination with long-acting B2-agonist or in addition to a long acting b2-agonists can be used to treat COPD
Second-Generation Antihistamines
- Acrivastine (Semprex) * - Acrivastine/pseudoephedrine (Semprex D)* - Cetirizine (Zyrtec) * - Cetrizine/pseudoephedrine (Zyrtec D) * - Desloratadine/pseudoephedrine + Clarinex-D 12 hours * + Clarinex-D 24 hour * + Fexofenadine (Allegra) * - Fexofenadine/pseudoephedrine: + Allegra D 12 hour * + Allegra D24 hour * + Levocetirizine (Xyzal) * + Loratadine (Claritin) * - Loratadine/pseudoephedrine (all ar ER tablets): + Alavert-D 12 hour * + Claritin-D 12 hour * + Claritin- D 24 hour *
What can prolonged systemic used of long-term oral corticosteroids result in?
- Adrenal suppression + supplemental steroids may need to be considered it this occurs - Poor wound healing - Immunosuppression - Candidiasis
What my Asthma be precipitated by?
- Allergens - Pollution - Exercise - Stress - upper respiratory infection (allergic reaction to viruses) - Certain medications (nonsteroidal antiinflammatory)
NASAL DECONGESTANTS
- An a-adrenergic agonists that act by constricting the blood vessels of the nasal mucous membranes - Many are available OTC for both local and systemic use - Long-term topical use can result in + Rebound swelling and congestion - Nose sprays should not be used for more than a few days + Unwanted side effects of adrenergic stimulation may occur - Phenylpropanolamine + used systemically as a decongestant (a-agonist action)
ALLERGIC RHINITIS
- An inflammation of the nasal airways that occurs when an allergen is inhaled in an individual with a sensitized immune system - Can be seasonal or perennial - Antihistamines (H1-receptor antagonists). The common tern antihistamine refers to agents that are H1 antihistamines or H1-blocker + Are widely used drugs
TOXICITY
- Antihistamine poisoning has become more common in recent years because of the easy accessibility of the agents in OTC preparations promoted as sleep aids - Excitation predominates in small children, and sedation can occur in adults - Death usually results from coma with cardiovascular and respiratory collapse - Treatment is directed at specific symptoms
What do the first-generation H1 antihistamines/ H1 blockers pharmacologic effects?
- Antihistaminic - Anticholingeric - Antiserotonergic - Sedative effects
INTRANASAL CORTICOSTEROIDS
- Are very effective for the treatment of moderate to severe allergic rhinitis and are considered firs-line therapy - Work by decreasing inflammation in the airways - Used to control the symptoms of + Rhinorrhea + Itching + Sneezing + Nasal congestion - Effective when given once daily - Onset of action is about 12 hours although full relief may take up to 7 days - Intranasal spray can also decrease ocular symptoms in pts with seasonal rhinitis
MEDICATIONS CURRENTLY AVAILABLE IN MDIS
- B-agonists, both specific and nonspecific - Corticosteroids - Cromolyn - Antimuscarinic drugs
Agents used to treat acute asthmatic attack
- B2-adrenergic agonists - Xanthines - Cromolyn - Corticosteroids - Leukotriene (LT) altering agents - Antimuscarinics
What do pts. with upper respiratory tract infections often take?
- B2-adrenergic agonists for bronchoconstriction - Antihistamines to reduce secretions - Expectorants to thin sputum - Antitussives to control coughing
INTRNASAL DECONGESTANTS
- Because they are less likely to have systemic adverse effects, intranasal decongestants are an alternative to oral decongestants - They can cause + Stinging + Burning + Sneezing + Dry throat or nose - They should be used for not more than 3 to 5 day in order to avoid rebound congestion - Rebound congestion is treated by discontinuing the intranasal decongestant and then having the pt use an intranasal corticosteroid or possibly undergoing a short course of oral steroids to help control symptoms
Common inhalers contain
- Beclomethasone (Qvar) - Fluticason (Flovent)
SIDE EFFECS ASSOCIATED WITH METHYLXANTHINES
- CNS Stimulation - Cardiac stimulation - Increased gastric secretion - Diuresis
OTHER EFFECTS (UNRELATED TO H1-BLOCKING EFFECTS)
- CNS effects - Anticholinergic effects
ASTHMA: LONG-ACTING B2-AGONISTS
- Carry a black box warning form the FDA about higher risk of asthma-related deaths with salmeterol therapy during a clinical trial
CNS stimulation is more common in
- Children - Elderly pts - Those who use a larger dose than prescribed
What is COPD further divided into?
- Chronic bronchitis - Emphysema
ASTHAMA
- Common respiratory disease - Characterized by + Reversible airway obstruction - Associated with + Reduction in expiratory airflow - A few hours later + inflammation occurs, resulting in an increase in secretion in the lungs and swelling in the bronchioles
METERED-DOSE INHALERS (MDI)
- Developed in the 1950s provides a useful method to administer certain medications to the respiratory tree - Preferred rout of delivery for most asthma drugs and includes the following: + Delivers the medication directly into the bronchioles, thereby keeping the dose low and side effects minimal + Bronchodilator effect is greater than that of a comparable oral dose + Inhaled dose can be accurately measures + Onset of action is rapid and predictable (versus unpredictable response with orally administered agents) + Is compact, portable, and sterile, making it ideal for the ambulatory patient
DISADVANTAGES OF MDIs
- Difficult to use properly (particularly for children) - Can be abused, with a resultant decrease in response - Additional pt. education is required to get the most form this does form - Often, a "spacer" is placed between the MDI and the mouth to increase the amount of drug delivered to the lungs
Some First-Generation Antihistamines
- Diphenhydramine (Benadryl) - Clemastine (Travist) - Chlorpheniramine * (Chlor-Trimeton)
Caution should be exercised when giving Zafirlukast to patients taking...
- Drugs metabolized by cytochrom P-450 isoenzyme 2c9 (tolbutamide, phenytoin, and carbamazepine) or - 3A/4 dihydropyridines, cyclosporin, astemizole, and cisapride
EXPECTORANTS AND MUCOLYTICS
- Drugs that promote the removal of exudate or mucus from the respiratory passages - Liquefying expectorants are drugs that promote the ejection of mucus by decreasing its viscosity - Mucolytics destroy or dissolve mucus - Some expectorants act through their ability to cause reflex stimulation of the vagus nerve, which increases bronchial secretions - Mucolytics: + Enzymes that are able to digest mucus, decreasing its viscosity + Acetylcysteine (Mucomyst) is a mucolytic used to loosen secretion in pulmonary disease, including cystic fibrosis and used orally as an antidote for acetaminophen toxicity.
SIDE EFFECTS OF IPRATROPIUM BROMIDE AND (ATROVENT) TIOTROPIUM BROMIDE (SPIRIVA)
- Dry mouth and bad taste + are minimized with administration by inhalation
LEUKOTRIENE MODIFIERS
- During an allergic reaction, cysteinyl Lt is released in the nasal mucosa causing congestion - LTRA montelukast (singulair) is approved for the treatment of seasonal and perennial allergic rhinitis - Montelukast is generally well tolerated. However, there are post-marketing reports of psychiatric symptoms (thought of suicide) and sleep disturbance
Zafirlukast (Accolate) Drug interactions
- Erythromycin and aspirin, and increases the effect of warfarin + Erythromycin lowers the level of Zafirlukast by about 40% + Aspirin raises Zafirlukast levels by about 50%
ZAFIRLUKAST (ACCOLATE)
- Found to raise the level of theophylline in the blood + Zafirlukast is an inhibitor of cytochrom P-450 3A/4 and a subrate for cytochrom P-450 2C9 + Alanine aminotransferase levels need to be monitored, and pts should discontinue drug immediately if the following occur ++ abdominal pain ++ nausea ++ Jaundice ++ Itching ++ Lethargy
What is the most popular expectorant?
- Guaifenesin, is contained in a variety of OTC products mixed with other active ingredients + Robitussin is available as guaifenesin alone (Robitussin plain) and mixed with an antitussive agent (Ronitussin DM)
CROMOLYN
- Has no + intrinsic bronchodilator + Antihistaminic action + Inflammatory action - Prevents the antigen-induced release of the following by preventing the influx of calcium provoked by immunoglobulin E (IgE) antibody interaction on the mast cell + Histamine + LTs + Other substances by sensitized mast cells - This group name that is given for these drugs + Mast cell degranulation inhibitors - Currently available in a metred-dose form like other inhalation agents
ASTHMA: SHORT-ACTING B2 AGONISTS
- Have specificity for the respiratory tree - Short-acting B2-Agonists, such as albuterol, may be administered +by inhalation (metered dose or nebulization with an air compressor) + Orally - Studies found that the overuse of these agents result in airway hyperresponsiveness and a decrease in the lung's response to them ***- Should be used primarily for the treatment of acute problems, not for the management of normal breathing function (Albuterol) - One major mistake that many asthmatic patients make is to rely on the albuterol inhaler and omit using the steroid inhaler. They do so because the albuterol gives them an immediate response
CHARACTERISTICS OF LONG-ACTING B2-AGONISTS: ASTHMA
- Improve lung function - Decrease symptoms - Reduce exacerbations of asthma - Rescue uses of short-acting B2 agonists
CHARACTERISTICS OF LONG-ACTING B2-AGONISTS: COPD
- Improve lung function and quality of life - Lower exacerbation rates in pts. with the disease
What is COPD associated with?
- In increase in the incidence of bronchospasm - Fixed airway obstruction
Adverse effects of Omalizumab
- Injection-site pain and bruising - Anaphylaxis can occur within 2 hours of injection but sometimes 4 days later
SIDE EFFECTS OF NUCALA
- Injection-site reactions - Headache - Fatigue - Back pain - Hypersensitivity reactions
INTRNASAL DOSE FORM
- Intranasal corticosteroids - Leukotriene modifiers - Mast cell stabilizers - Intranasal anticholinergic drugs
ANTIMUSCARINIC
- Ipratropium bromid (Atrovent) + Bronchodilating effect is additive with that of the B-agonists + Is avaialbel as in combination with albuterol sulfate (Combivent) and is used in the pts. with COPD who is using a regular aerosol inhalation bronchodilator and continues to have evidence of bronchospasm - Tiotropium bromide (Spiriva) - The following are not approved by the FDA for treatment of asthma + Ipratropium bromide + Tiotropium bromide
ANTI-IMMUNOGLOBULIN E ANTIBODIES (OMALIZUMAB (XOLAIR))
- Is FDA-approved for adjunctive use in pts + At least 12 years old + who have well-documented specific allergies + Moderate-to-severe persistent asthma that is not well controlled with inhaled corticosteroid with or without a long-acting B2-agonist - It is expensive - It is advised that pts be kept under observation for 2 hours after the frist three injections and for 30 minutes after subsequent injections + pts are educated about the sings and symptoms of anaphylaxis and when to self-administer injectable epinephrine
What does the release of histamine cause?
- Itchy - Water eyes - Runny nose
LEUKOTRIENE MODIFIERS
- LT patheay inhibitors block the effects of the release of LTs. + Zileuton (Zylfo) is a 5-lipoxygenase inhibitor that works by preventing the synthesis of the LTs - LT-receptors antagonists (LTRAs) ++ Not as effective as corticosteroid inhalers 1. Zafirlukast (Accolate) 2. Montelukast (singulair) ++ both are effective when taken orally
Why should a dental hygienist be familiar with H1-antihistamines or H1-blockers?
- Many pts have seasonal allergies or allergic rhinitis (e.g., hay fever) that makes dental treatment difficult. The dentist may prescribe, or the pt may self-medicate with, antihistamines before a dental procedure to reduce the symptoms of hay fever and make it easier for the pt to breathe - A mild allergic reaction to a drug may be treated with antihistamines in the dental office. If the allergic reaction is severe, epinephrine is the drug of choice. - Pts taking antihistamines may experience side effects, such as xerostomia, but the second-generation antihistamines have less anticholinergic effects - Antihistamines, especially first-generation, interact with many other drug groups and their CNS effects are additive with those of other CNS depressants
ANTITUSSIVES
- May be opioids or related agents used fro the symptomatic relief of nonproductive cough. Opioids are most effective, but because of their addiction properties, other agents are often used. - Codeine-containing cough preparations are commonly used, but their histamine-releasing properties may precipitate bronchospasm. - Dextromethorphan + Does not cause the release of histamine + May potentiate the effects of CNS depressants + Available both alone and in combination with other ingredients + By impairing coughing, dextromethrophan may not allow the secretions to be cleared from the lungs
INTERLEUKIN-5 ANTIBODY ANTAGONISTS
- Mepolizumab (Nucala) - Relisumab (Cinqair)
INTERLEUKIN-5 ANTIBODY ANTAGONISTS
- Mepolizumab (Nucala) and relisumab (Cinqair) - Interleukin-5 is the major cytokine that is responsible for the following that are throughout to play a role in the allergy process + Growth + Differentiation + Recruitment + Activation + Survival of eosinophils - Inhibits the signaling of interleukin-5 which blocks the production of eosinophils and results in decreased inflammation and a reduction in asthma symptoms. + the mechanism of action in controlling asthma symptoms has not been established - Nucala + indicated for those over the age of 12 + administered subcutaneously every 4 weeks - Cinqair + indicated for persons over 18 and add-on maintenance therapy for severe asthma with an eosinophil type. + administered intravenously every 4 weeks in a health care setting by a health professional because of the risk of anaphylaxis + Oropharyngeal pain is the most common adverse reaction + Reports of hypersensitivity reactions
DRUGS USED TO TREAT RESPIRATORY DISEASES
- Metered-Dose Inhalers - Sympathomimetic agents + Short-Acting B2 Agonists + Long-Acting B2 Agonists - Corticosteroids - Leukotriene Modifiers - Cromolyn - Methylxanthines - Antimuscarinic - Anti-Immunoglobulin E Antibodies - Interleukin-5 Antagonists - Agents used to manage upper respiratory infections + Expectorants and Mucolytics + Antitussives
ADVERSE EFFECTS OF INTRANASAL CORTICOSTEROIDS
- Mild dryness - Irritation - Burning - Bleeding of the nasal mucosa - Sore throat - Epistaxis - Headache - Ulceration - Mucosal atrophy - Growth suppression in children wit newer intranasal corticosteroids (Ciclesonide, Fluticasone, Propionate, Mometasone) - Beclomethasone might slightly slow the growth rate in children
CORTICOSTEROIDS: ASTHMA
- More effective LT modifiers, long-acting B2-agonists, cromolyn and theophylline in + Improving pulmonary function + Preventing symptoms of exacerbations + Reducing the need for emergency room visits + Decreasing the number of asthma- related deaths - Most pts. experience a positive response at relatively low doses - Optimal dose may decrease or increase over time but it should always be tailored to the lowest possible dose + Dose depends on the inhaled corticosteroid and the inhaler device
ADVERSE EFFECTS OF ORAL DECONGESTANTS
- Most common adverse effects + Insomnia + Excitability + Headache + Nervousness + Anorexia + Palpitations + Tachycardia - Other adverse effects + Arrhythmias + Hypertension + Nausea + Vomiting + Urinary retention - Should be used with caution in pts. with + Cardiovascular disease + Hypertension + Diabetes + Hyperthyroidism + Closed-angle glaucoma + Bladder neck obstruction
ADVERSE REACTIONS OF INTRANASAL DOSE FORM
- Nasal discomfort - Epitaxis - Headache - Some somnolence - Nasal mucosal irritation has been reported with the long-term use of intranasal antihistamines - Bad taste with intranasal azelastine
ASTHMA: SIDE EFFECTS OF SHORT-ACTING B2 AGONISTS
- Nervousness - Tachycardia - Insomnia
DECONGESTANTS
- Oral decongestants - Intranasal decongestants
ORAL DECONGESTANTS
- Pseudoephedrine and phenylephrine are a-adrenergic agonists that cause a vasoconstriction of the nasal mucosa - Thought to primarily stimulate a1-adrenergic receptors on the venous sinusoids - Used to treat congestion associated with allergic rhinitis, not sneezing or mucosal discharge - Often used with H1 antihistamines - Phenylephrine, thought less effective than pseudophedrine, is now in many OTC oral decongestants products because of the legal restrictions placed on the sale of pseudoephedrine
DENTAL IMPLICATIONS OF THE RESPIRATORY DRUGS
- Pts with severes COPD can have pulmonary hypertension, increasing the risk for cardiac arrhythmias - Stress should be minimized and adrenal supplementation instituted for pts taking long-term oral steroids and the dental procedures are likely to produce severe stress - Pts. prone to development of respiratory failure, if given oxygen (either alone or with nitrous oxide) or CNS depressants, may manifest acute respiratory failure - Asprin should be avoided in pts with asthma and erythromycin may alter the metabolism of theophylline - Emergency equipment and medications should be available wht these pts. are undergoing treatment
As with all drugs that depress the CNS, stimulation or excitation can occur in a few cases. Symptoms include
- Restlessness - Excitation - Severe cases, convulsions
CORTICOSTEROIDS: ASTHMA: CANDIDIASIS
- Result from long-term use of an inhalation corticosteroid - When the dental professional performs an oral examination of any patients using steroid inhalers, any symptoms of candidiasis should be noted and treated
PHARMACOLOGIC EFFECTS OF H1 ANTIHISTAMINES/ H1 blockers
- Second generation H1 antihistamines penetrate poorly into the CNS and so are less likely to cause sedation - Because they have a chemical structure similar to that of histamine, they can bind with the H1-receptor and prevent of block the action of histamine (if it is released)
CNS DEPRESSION
- Sedation with first-generation antihistamine is additive with that caused by other CNS depressant drugs - As with all drugs that depress the CNS, stimulation or excitation can occur in a few cases
SYMPATHOMIMETIC AGENTS
- Short-Acting B2 Agonists - Long-Acting B2 Agonists
LONG-TERM ORAL CORTICOSTEROIDS
- Such as prednisone, may be necessary in some severely asthmatic pts. and even in patients with moderate asthma, especially during respiratory infections.
What can the pharmacologic effect of antihistamines be divided into?
- Those caused by blocking of histamine at the H1-receptor - Those independent of this effect
- PARTIAL PRESSURE OF CARBON DIOXIDE (Paco2): COPD - PARTIAL PRESSURE OF OXYGEN (Pao2): COPD
- Ventilation is compromised with pts. who have COPD. and experience a gradual increase in Paco2 over time. + This mechanism become resistant to changes in Paco2, a new stimulus emerges, the partial pressure of Pao2
MAST CELL STABILIZERS
- When taken before the onset of triggers, it prevents allergic rhinitis symptoms - It is well tolerated with few adverse effects - it must be used four times a day and is less effective than intranasal corticosteroids
METHYLXANTHINES
- Xanthines and methylxanthines consist of + Theophylline ++ used as a bronchodilator ++ Combined with ethylenediamine tor produce aminophylline, which is more soluble ++ used to treat persistent asthma and bronchospasm associated with chronic bronchitis and emphysema ++ Bronchodilation is the major therapeutic effect desired + Cafeeine + Theobromine - Intravenous aminophylline and rapidly absorbed oral liquid preparations are used to manage acute asthmatic attacks and status asthmaticus - To manage persistent asthma, sustained-release preparations in tablet or capsule form are used. - Blood drug levels may be measured in pts. undergoing long-term theophylline therapy to determine whether the dose they are taking is appropriate
Which two agents have been reported to cause life-threatening hepatic injury?
- Zafirlukast - Zileuton
COPD: SHORT-ACTING B2 AGONISTS
- used for acute relief in pts with intermittent symptoms of COPD - These pts. typically present with midl airflow obstruction and their symptoms are usually due to exertion - Can improve forced expiratory volume in one second and can relieve symptoms
Respiratory drugs
-B2 Agonists -Corticosteroids -Leukotriene Modifiers -Mast Cell Inhibitors -Anticholinergic Drugs -Methylxanthines
INTRANASAL ANTICHOLINERGIC DRUGS
-Ipratropium bromide, a quaternary amine drug, blocks acetylcholine receptors, thereby decreasing rhinorrhea in persons with allergic rhinitis - Poorly absorbed systemically and does not readily cross the blood-brain barrier - Can cause dry nose and mouth epistaxis, and pharyngeal irritation- If inadvertently placed in the eye, ipratropium bromide can raise intraocular pressure. - It should be used with caution in pts with glaucoma
ADVERESE REACTIONS OF THE FOLLOWING LT-RECEPTOR ANTAGONISTS (LTRAs) + ZAFIRLUKAST (ACCOLATE + MONTELUKAST (SINGULAIR)
-Irritation of the stomach mucosa - Headache - Alteration of liver function test Values
AGENTS USED TO MANAGE UPPER RESPIRATORY INFECTIONS
-Nasal decongestants + Pseudoephedrine (Sudafed, Sucrets, in Actifed) ++ Both an a-adrenergic agonist and b-adrenergic against is used systemcially as a nasal decongestant + Phenylephrin (Neo-Synephrine, Sinex Allerest) ++ used topically as a nasal spray -Expectorants and Mucolytics -Antitussives
DISEASES TREATED WITH RESPIRATORY DRUGS INCLUDE:
1. Asthma 2. COPD 3. Upper respiratory tract infections
What two groups are noninfectious respiratory diseases divided into?
1. Asthma 2. COPD + Chronic bronchitis + Emphysema
What are the five common antihistamines?
1. Brompheniramine (Dimetane) 2. Chlorpheniramine (Chlor-Trimeton) 3. Diphenhydramine (Bendadryl) 4. Fexofenadine (Allegra) 5. Loratadine (Claritin
*** STEPWISE APPROACH FOR MANAGING ASTHMA IN CHILDREN OLDER THAN 12 YEARS AND ADULTS
1. Intermittent: +SABA, as needed 2. Mild persistent: +Low dose ICS or +LM 3. Moderate persistent + Low-dose ICS + LABA or medium-dose ICS or + Low-dose ICS + LM 4. Severe persistent: +Medium-dose ICS + LABA or + Medium-dose ICS + LM 5. Severs persistent: + High-dose ICS + LABA + or Consider omalizumab for pts. with allergies 6. Severe persistent: + High-dose + ICS + LABA + oral corticosteroids or Consider omalizumab for pts. with allergies
What can asthma be classified as?
1. Intermittent: - Experience symptoms less than two times a month and the symptoms do not interfere with normal activity or 2. Persistent: - Occurs any where from more than twice a week to all day long - Can cause minor limitation of normal activities. + Mild + Moderate + Severe
What percent of the population has some type of pulmonary disease?
10%
What is suggested that the rate of oxygen be administered be limited to in pts. with severe COPD?
3 L/min, other literature recommends oxygen by nasal cannula be used during a dental appt. especially if pain or stress ie expected (increased oxygen demand)
What do many pts. receive for the treatment of COPD?
A combination of MDI containing an antimuscarinic drug and a B2-agonist
A mucolytic used to loosen secretion in pulmonary disease, including cystic fibrosis and is also used orally as an antidote for acetaminophen toxicity.
Acetylcysteine (Mucomyst)
***What is emphysema characterized by?
Alveolar destruction with air space enlargement and airway collapse
What is the drive for ventilation (breathing) stimulated by in a normal person?
An elevation in the partial pressure of carbon dioxide (Paco2) + the partial pressure of oxygen (Pao2) can vary widely without stimulating ventilation in the normal pt.
What do allergen's trigger the response of?
Antibody IgE, which binds to mast cells and basophils containing histamine
ANTICHOLINGERIC EFFECTS
Antihistamines block acetylcholine receptors to varying degrees and produce an anticholinergic effect (cholinergic blockade) that is weaker than but similar to that of atropine
VASCULAR SMOOTH MUSCLE (VESSELS)
Antihistamines block the dilation of the of the vascular smooth muscle that histamine produces histamine
CUTANEOUS NERVE ENDINGS
Antihistamines can suppress the itching and pain associated with histamine-mediated release of inflammatory chemical mediator (cytokines, LT, PGs) at the cutaneous nerve ending
CNS EFFECTS
Antihistamines produce varying degrees of CNS depression
Which drugs have a cross-hyperreactivity with peanut and soybean allergies?
Antimuscarinic's + Ipratropium bromid (Atrovent) + Tiotropium bromide (Spiriva)
What are considerded the frist-line agents in COPD?
Antimuscarinics but B2-adrenergic agonists are also used to produce bronchodilation
What should an asthma pt. bring to be used prophylactically or in the management of an acute asthmatic attack in the dental office?
B2 agonist inhaler
What is drugs are sometimes combined for the treatment of pts. with COPD?
B2- agonists and antimuscarinic drugs
NONVASCULAR (BRONCHIAL) SMOOTH MUSCLE
Because other autacoids (physilogically active subtances produced by and acting within the body [I.e.; bradkinin]) are also released in an anaphylactic reaction, antihistamines are not effective in counteracting all the bronchoconstriction present during that reaction
CAPILLARY PERMEABILITY
Blocked by histamine +Less tissue edema occurs form the transport of the serum into the intracellular spaces