Chapter 11. Colds and Allergy

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Chapter 10. Prevention of Pregnancy and Sexually Transmitted Infections
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  Print Close Window Handbook of Nonprescription Drugs  > Chapter 11. Colds and Allergy Colds and Allergy: Introduction Colds and allergic rhinitis are two of the most common conditions for which patients access the health care system. This chapter reviews the role of the plethora of nonprescriptionproducts that patients may use to self-treat symptoms associated with those two disorders. Colds  A cold, also known as the common cold, is a viral infection of the upper respiratory tract. According to some estimates, one billion cases of colds occur annually, making this illnessone of the top five diagnosed in the United States. 1  Children usually have 6-10 colds per year. 1  Adults younger than 60 years typically have 2-4 colds per year, whereas adults older than 60 years usually have 1 cold per year. 1  Colds may occur at any time, but in the United States, the cold season occurs from late August through early April. 1 Colds are the leading cause of work and school absenteeism. Colds are usually self-limiting; however, because symptoms are bothersome, patients frequently self-medicate andspend an estimated $7 billion annually on nonprescription cold and cough products. 2 Pathophysiology of Colds Colds are limited to the upper respiratory tract and primarily affect the following respiratory structures: pharynx, nasopharynx, nose, cavernous sinusoids, and paranasal sinuses.The respiratory tract’s intricate host-defense system usually protects the body from infectious and foreign particles. The respiratory tract, especially the nose, is well perfused andinnervated. The nose contains sensory, cholinergic, and sympathetic nerves. When stimulated by an infectious (i.e., a cold) or allergic (i.e., allergic rhinitis) process, those nervesplay a role in the resulting symptoms and are also targets for some nonprescription therapies. Stimulation of sensory fibers by mechanical and thermal stimuli or by mediators suchas histamine and bradykinin results in sneezing. Cholinergic and sympathetic nerves are involved in congestion because they innervate glands and arteries that supply the glands.Cholinergic stimulation dilates arterial blood flow, whereas sympathetic stimulation constricts arterial blood flow. The sensory, cholinergic, and sympathetic nerves also respond to avariety of neuropeptide neurotransmitters.More than 200 viruses cause colds. The majority of colds in children and adults are caused by rhinoviruses. 1  Other viruses known to cause colds include coronaviruses,parainfluenza, adenoviruses, echoviruses, respiratory syncytial viruses, and coxsackieviruses. Viral and bacterial coinfection (usually with group A beta-hemolytic streptococci)occurs but is rare. Rhinoviruses bind to intercellular adhesion molecule-1 receptors on respiratory epithelial cells in the nose and nasopharynx. 3  Once inside the epithelial cells, thevirus replicates and infection spreads to other cells. 3  Peak viral concentrations occur 2-4 days after initial inoculation, and viruses are present in the nasopharynx for 16-18 days. 3 Infected cells release chemokine “distress signals,” and cytokines then activate inflammatory mediators and neurogenic reflexes. These activation processes result in recruitment of additional inflammatory mediators, vasodilatation, transudation of plasma, glandular secretion, and stimulation of pain nerve fibers and sneeze and cough reflexes. Inflammatorymediators and parasympathetic nervous system reflex mechanisms cause hypersecretion of watery nasal fluid. Viral infection ends once enough neutralizing antibody (secretoryimmunoglobulin A [IgA] or serum IgG) leaks into the mucosa to end viral replication.The most efficient mode of viral transmission is self-inoculation of the nasal mucosa or conjunctiva after contact with viral-laden secretions on animate (e.g., hands) or inanimate(e.g., doorknobs and telephones) objects. Aerosol transmission is also common. Increased susceptibility to colds has been linked to higher exposure rates (e.g., increasedpopulation density in classrooms or day care centers); allergic disorders affecting the nose or pharynx; less diverse social networks; and a weakened immune system due to smoking, a sedentary lifestyle, chronic (i.e., ≥1 month) psychological stress, or sleep deprivation (e.g., poor sleep quality or <7 hours of sleep per night). 1,4,5  There is conflictinginformation about increased susceptibility due to cold environments, sudden chilling, or exposure to central heating (i.e., low humidity). 1,6  Walking outside barefoot, teething, or suffering from enlarged tonsils or adenoids has not been shown to increase susceptibility to viral upper respiratory infections. 1 Clinical Presentation of Colds  A predictable sequence of symptoms appears 1-3 days after infection. 7  Sore throat is the first symptom to appear, followed by nasal symptoms, which dominate 2-3 days later.Cough, although an infrequent symptom (<20%), appears by day 4 or 5. Physical assessment of a patient with a cold may yield the following findings: slightly red pharynx withevidence of postnasal drainage, nasal obstruction, and mildly to moderately tender sinuses on palpation. During the first 2 days of a cold, patients may report clear, thin, and/or watery nasal secretions. As the cold progresses, the secretions become thicker and the color may change to yellow or green. When the cold begins to resolve, the secretions againbecome clear, thin, and/or watery. Patients may have low-grade fever, but colds are rarely associated with a fever above 100°F (37.8°C). Rhinovirus cold symptoms persist for about7-14 days. 7  Signs and symptoms of a cold may be confused with symptoms of influenza and other respiratory illnesses (Table 11-1).Most people do not have complications from colds. However, complications of colds may be severe and, rarely, life-threatening. Complications include sinusitis, middle ear infections, bronchitis, pneumonia, and exacerbations of asthma or chronic obstructive pulmonary disease. TABLE 11-1 Differentiation of Colds and Other Respiratory Disorders IllnessSigns and Symptoms  Allergic rhinitisWatery eyes; itchy nose, eyes, or throat; repetitive sneezing; nasal congestion; watery rhinorrhea; red, irritated eyes with conjunctival injection AsthmaCough, dyspnea, wheezingBacterial throatinfectionSore throat (moderate-severe pain), fever, exudate, tender anterior cervical adenopathyColdsSore throat (mild-moderate pain), nasal congestion, rhinorrhea, sneezing common; low-grade fever, chills, headache, malaise, myalgia, and cough possibleCroupFever, rhinitis, and pharyngitis initially, progressing to cough (may be “barking” cough), stridor, and dyspneaInfluenza Myalgia, arthralgia, fever ≥ 100°F-102°F (37.8°C-38.9°C), sore throat, nonproductive cough, moderate-severe fatigue Otitis mediaEar popping, ear fullness, otalgia, otorrhea, hearing loss, dizzinessPneumonia or bronchitisChest tightness, wheezing, dyspnea, productive cough, changes in sputum color, persistent fever Sinusitis Tenderness over the sinuses, facial pain aggravated by Valsalva’s maneuver or postural changes, fever ≥101.5°F (38.6°C), tooth pain, halitosis, upper respiratory tract symptoms for ≥7 days with poor response to decongestants West Nile virusinfectionFever, headache, fatigue, rash, swollen lymph glands, and eye pain initially, possibly progressing to GI distress, CNS changes, seizures, or paralysisWhooping coughInitial catarrhal phase (rhinorrhea, mild cough, sneezing) of 1-2 weeks, followed by 1-6 weeks of paroxysmal coughingKey: CNS = Central nervous system; GI = gastrointestinal. PharmacyLibrary | Print: Chapter 11. Colds and Allergyhttp://www.pharmacylibrary.com/popup.aspx?aID=786349&print=yes_c...1 of 223/15/2015 1:18 AM    Treatment of Colds Treatment GoalsBecause there is no known cure for colds, the goal of therapy is to reduce bothersome symptoms and prevent transmission of cold viruses to others.General Treatment Approach Antibiotics are ineffective against viral infections and the mainstay of treatment is nonpharmacologic therapy. If a patient desires to self-treat, a stepwise approach using single-entityproducts targeting specific symptoms is preferred over the use of combination products (Figure 11-1) because symptoms appear, peak, and resolve at different times. 7  Patienteducation regarding the administration of intranasal drugs (Table 11-2) and ocular drugs (see Chapter 27) is important. Not all patients should self-treat colds (see the exclusions for  self-treatment listed in Figure 11-1).  Self-care of the common cold. Key: AH = Antihistamine; AIDS = acquired immunodeficiency syndrome; CAM = complementary and alternative medicine; CHF = congestive heart failure; COPD =chronic obstructive pulmonary disorder; OTC = over-the-counter. ( Source:  Adapted from Reference 7.) TABLE 11-2 Administration Guidelines for Nasal Dosage Formulations General Instructions ã Clear nasal passages before administering the product.ã Wash your hands before and after use.ã Gently depress the other side of the nose with finger to close off the nostril not receiving the medication.ã Aim tip of product away from nasal septum to avoid accidental damage to the septum.ã Breathe through mouth and wait a few minutes after using the medication before blowing the nose. Nasal SpraysNasal Inhalers ã Gently insert the bottle tip into one nostril, as shown in drawing A.ã Keep head upright. Sniff deeply while squeezing the bottle.Repeat with other nostril.ã Warm the inhaler in hand just before use.ã Gently insert the inhaler tip into one nostril, as shown in drawing C. Sniff deeply while inhaling.ã Wipe the inhaler after each use. Discard after 2-3 months even if the inhaler still smells medicinal. PharmacyLibrary | Print: Chapter 11. Colds and Allergyhttp://www.pharmacylibrary.com/popup.aspx?aID=786349&print=yes_c...2 of 223/15/2015 1:18 AM  General Instructions Pump Nasal SpraysNasal Drops ã Prime the pump before using it the first time. Hold the bottle withthe nozzle placed between the first two fingers and the thumbplaced on the bottom of the bottle.ã Tilt the head forward.ã Gently insert the nozzle tip into one nostril (see drawing B). Sniff deeply while depressing the pump once.ã Repeat with other nostril.ã Lie on bed with head tilted back and over the side of the bed, as shown in drawing D.ã Squeeze the bulb to withdraw medication from the bottle.ã Place the recommended number of drops into one nostril. Gently tilt head from side to side.ã Repeat with other nostril. Lie on bed for a couple of minutes after placing drops in the nose.ã Do not rinse the dropper. PharmacyLibrary | Print: Chapter 11. Colds and Allergyhttp://www.pharmacylibrary.com/popup.aspx?aID=786349&print=yes_c...3 of 223/15/2015 1:18 AM  General Instructions Note:  Do not share the drug with anyone. Discard solutions if discolored or if contamination is suspected. Remove caps before use and replace tightly after each use. Do not useexpired products. Nonpharmacologic Therapy Although evidence of efficacy is lacking, popular therapies include increased fluid intake, adequate rest, a nutritious diet as tolerated, and increased humidification with steamyshowers, vaporizers, or humidifiers. Vaporizers superheat water to produce steam and can accommodate medications such as Vicks Vapo Steam (camphor 6.2%). In contrast,humidifiers use fans or ultrasonic technology to produce a cool mist and cannot accommodate additives. Saline nasal sprays or drops moisten irritated mucosal membranes andloosen encrusted mucus; salt gargles may ease sore throats. Food products such as tea with lemon and honey, chicken soup, and hot broths are soothing. Limited evidencesuggests that a number of substances in chicken soup could have anti-inflammatory activity. 8  Milk products should not be withheld given the lack of evidence that milk increasescough or congestion. Medical devices, such as Breathe Right nasal strips, are marketed for temporary relief from nasal congestion and stuffiness resulting from colds and allergies.Those devices lift the nares open, thus enlarging the anterior nasal passages. Aromatic oil (camphor, menthol, and eucalyptus) products such as Theraflu Vapor Patch (ages  ≥ 12years) and Vicks VapoRub (ages ≥ 2 years) ease nasal congestion and improve sleep by producing a soothing sensation. 9  Children should be supervised closely when theseproducts are used because aromatic oils can irritate the eyes and skin and ingesting large quantities can be toxic.Nondrug therapy for infants includes upright positioning to enhance nasal drainage. Because children typically cannot blow their own noses until about 4 years of age, carefullyclearing the nasal passageways with a bulb syringe may be necessary if accumulation of mucus interferes with sleeping or eating. To use the syringe and avoid harm to the child,the caregiver should squeeze the large end of the bulb before  inserting it, continue to squeeze the bulb while gently inserting the tip into the infant’s nose, and then slowly releasethe squeezing pressure to draw out fluid. After the pressure is completely released, the syringe is removed from the infant’s nose and the fluid expelled from the syringe by againcompressing the bulb.Proper hand hygiene reduces the transmission of cold viruses. The Centers for Disease Control and Prevention (CDC) encourages frequent hand cleansing with soap or soapsubstitutes (e.g., hand sanitizers). 1  Not all hand sanitizers are effective at eradicating rhinoviruses from hands. Alcohol-based products containing isopropanol or ethanol (60%-80%concentration) are preferred but are short-acting and require frequent reapplication. 10  Chlorhexidine, povidone-iodine, and quaternary ammonium compounds are also effectivealone or in combination with alcohol-based products. 10  Alcohol-based nasal sanitizers (e.g., Nozin) are also available but lack evidence of efficacy and safety. Use of antiviraldisinfectants such as Lysol (kills >99% of rhinoviruses after 1 minute) and antiviral tissues such as Kleenex Anti-Viral (tissue layer containing citric acid and sodium lauryl sulphate)may also help prevent transmission to others.Pharmacologic TherapyDecongestantsDecongestants specifically treat sinus and nasal congestion. Decongestants are adrenergic agonists (sympathomimetics). Stimulation of alpha-adrenergic receptors constricts bloodvessels, thereby decreasing sinusoid vessel engorgement and mucosal edema. There are three types of decongestants. Direct-acting decongestants (e.g., phenylephrine,oxymetazoline, and tetrahydrozoline) bind directly to adrenergic receptors. Indirect-acting decongestants (e.g., ephedrine) displace norepinephrine from storage vesicles inprejunctional nerve terminals and tachyphylaxis can develop as stored neurotransmitter is depleted. Mixed decongestants (e.g., pseudoephedrine) have both direct and indirectactivity.Systemic nonprescription decongestants include pseudoephedrine and phenylephrine. Intranasal nonprescription decongestants include the short-acting decongestants ephedrine,levmetamfetamine (l-desoxyephedrine), naphazoline, phenylephrine, and propylhexedrine, and the long-acting decongestants xylometazoline (8-10 hours) and oxymetazoline (12hours). Ophthalmic nonprescription decongestants are also available (see Chapter 27). PharmacyLibrary | Print: Chapter 11. Colds and Allergyhttp://www.pharmacylibrary.com/popup.aspx?aID=786349&print=yes_c...4 of 223/15/2015 1:18 AM
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