Colds and Allergy: Ch 11

Colds

A cold, also known as the common cold, is a viral infection of the upper respiratory tract

the cold season occurs from late August through early April.

The majority of colds in children and adults are caused by rhinoviruses

Peak viral concentrations occur 2-4 days after initial inoculation, and viruses are present in the nasopharynx for 16-18 days

Clinical Presentation of Colds

predictable sequence of symptoms appears 1-3 days after infection

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.

slightly red pharynx with evidence 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.

Patients may have low-grade fever, but colds are rarely associated with a fever above 100°F (37.8°C)

Treatment Goals

Because 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

If a patient desires to self-treat, a stepwise approach using single-entity products targeting specific symptoms is preferred over the use of combination product because symptoms appear, peak, and resolve at different times

Nonpharmacologic Therapy

evidence of efficacy lacking

include increased fluid intake, adequate rest, a nutritious diet as tolerated, and increased humidification with steamy showers, vaporizers, or humidifiers

vaporizers can accommodate medications

Breathe Right nasal strips,

Limited evidence suggests that a number of substances in chicken soup could have anti-inflammatory activity.

Nondrug Therapy for Infants

upright positioning to enhance nasal drainage

clearing the nasal passageways with a bulb syringe may be necessary if accumulation of mucus interferes with sleeping or eating

squeeze bulb before inserting

Reduce Transmission

Proper hand hygiene reduces the transmission

use soap or soap substitute

not all hand sanitizers effective on rhinoviruses

alcohol based are preferred but require frequent application

Chlorhexidine, povidone-iodine, and quaternary ammonium compounds are also effective alone or in combination with alcohol-based products

Use of antiviral disinfectants 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.

Decongestants

specifically treat sinus and nasal congestion

are adrenergic agonists (sympathomimetics)

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 in prejunctional nerve terminals and tachyphylaxis can develop as stored neurotransmitter is depleted. Mixed decongestants (e.g., pseudoephedrine) have both direct and indirect activity.

indicated for temporary relief of nasal and eustachian tube congestion and for cough associated with postnasal drip

NOT for sinusitis

Adhering to FDA-approved doses of decongestant products is very important, given that acute overdose can be life-threatening, especially in children. Systemic decongestant overdoses cause excessive central nervous system (CNS) stimulation, paradoxical CNS depression, cardiovascular collapse, shock, and coma

Decongestant Side Effects

include cardiovascular stimulation (e.g., elevated blood pressure, tachycardia, palpitation, or arrhythmias) and CNS stimulation (e.g., restlessness, insomnia, anxiety, tremors, fear, or hallucinations)

Children and older adults are more likely than other age groups to experience adverse effects

more common with systemic decongestants because topical decongestants are minimally absorbed

accidental ingestion of nasal or ocular decongestants can cause serious adverse effects such as nausea, vomiting, drooling, hypotension, hyperthermia, lethargy, sedation, and coma

Adverse effects specifically related to topical decongestants include propellant- or vehicle-associated effects (e.g., burning, stinging, sneezing, or local dryness) and trauma from the tip of the administration device

Products specifically marketed for patients with hypertension (e.g., Coricidin HBP) do not contain decongestants. Those products usually contain a combination of ingredients that may or may not be appropriate depending on a patient's symptoms

Topical decongestants are convenient dosage forms and are effective in relieving nasal congestion; however, their use is limited to 3-5 days owing to concerns about RM

Antihistamines

not effective in reducing rhinorrhea and sneezing due to colds

a combination of first-generation (sedating) antihistamines and decongestants showed some benefit in adults, but the significance of the data is questionable

whether potential benefits of sedating antihistamines outweigh known risks associated with these drugs.

Local Anesthetics

Local anesthetic products may be used every 2-4 hours

history of allergic reactions to anesthetics to avoid products containing benzocaine. Benzocaine has also been associated with methemoglobinemia, especially in children younger than 2 years, and should be avoided in this age group

Local antiseptics are not effective for viral infections

Systemic Analgesics

Systemic analgesics (e.g., aspirin, acetaminophen, ibuprofen, or naproxen) are effective for aches or fever sometimes associated with colds

Aspirin-containing products should not be used in children with viral illnesses because of the risk of Reye's syndrome

Antitussives and Protrussives (Expectorants)

When present, cough associated with colds is usually nonproductive.

antitussives not recommended

Pregnancy

balance between risk and benefit. Because most colds are self-limiting with bothersome rather than life-threatening symptoms, many health care providers recommend nondrug therapy

drugs are considered, those with a long record of safety in animals and humans are preferred. To minimize possible adverse effects on the fetus or newborn, pregnant or lactating women should be advised to avoid products labeled as "extra strength," "maximum strength," or "long-acting," as well as combination products

avoid systemic decongestants

no pseudoephedrine

Oxymetazoline is poorly absorbed after intranasal administration and is the preferred topical decongestant during pregnancy.

Breast Feeding

pseudoephedrine to be compatible with breast-feeding and to be the preferred decongestant for lactating mothers.

No human data are available for intranasal phenylephrine and oxymetazoline, so they are considered "probably compatible" in lactating mothers

decongestants may decrease milk production, lactating mothers should monitor their milk production and drink extra fluids as needed

Dextromethorphan, guaifenesin, benzocaine, camphor (topical), and menthol (topical) have low risks of birth defects and have been found to be compatible with breast-feeding

Children

controversial owing to the lack of clinical evidence of safety and efficacy in this age group.

o address the issue of inaccurate dosing, FDA released guidelines in May 2011 for liquid nonprescription drug products that include any type of dispensing device (dropper, cup, syringe, or spoon)

Complimentary

concluded that oral zinc (lozenges or syrup) was effective in reducing cold symptoms or duration of the cold if started within 24 hours of symptom onset and administered every 2 hours while patient is awake. The study also reported prophylaxis with zinc for at least 5 months reduced the incidence of colds in healthy patient

trials showed that, although routine use of high-dose vitamin C does not appear to prevent colds in the general population, it did reduce the duration by about 8% in adults and 14% in children

Using vitamin C as treatment after the onset of a cold was not effective at reducing severity or duration of symptoms

Doses of 4 g/day or greater are associated with diarrhea and other GI symptoms and, therefore, should not be recommended.

Products that claim to strengthen the immune system such as Airborne, Emergen-C Immune+, vitamin D, etc. are available but have not been proved to be effective in preventing colds. Various probiotic products are available and emerging research suggests that they may help support the immune system and prevent colds

Allergic Rhinitis

Allergic rhinitis, a systemic disease with prominent nasal symptoms

An estimated 8% of adults and 11% of children in the United States are newly diagnosed with allergic rhinitis annually.

Symptoms of allergic rhinitis generally begin after the second year of life, and the disease is prevalent in children and adults ages 18-64 years

triggered by indoor and outdoor environmental allergens

Clinical Presentation

Classification depends on the timing and duration of symptoms. Symptoms can be further classified as mild or moderate-severe

Treatment Goals

Allergic rhinitis cannot be cured. The goals of therapy are to reduce symptoms and improve the patient's functional status and sense of well-being. Treatment is individualized to provide optimal symptomatic relief and/or control

General Treatment Approach

3 step treatment

1-allergen avoidance

2-pharmacotherapy

3-immunotherapy

Nonpharmacologic Therapy

Allergen avoidance is the primary

Avoidance strategies depend on the specific allergen

Many allergens

Pharmacologic Therapy

Intranasal corticosteroids (INCS) have been shown to be the most effective treatment for most symptoms of allergic rhinitis

options include ocular and oral antihistamines, topical and oral decongestants, and mast cell stabilizers

INCS, antihistamines, and mast cell stabilizers should be used regularly rather than episodically. Patients should start taking those products at least 1 week before symptoms typically appear or as soon as possible before expected allergen exposures.

Intranasal Corticosteroids

very effective treatments for nasal symptoms such as itching, rhinitis, sneezing, and congestion as they inhibit multiple cell types and mediators, including histamine, and effectively stop the "allergic cascade."

Triamcinolone acetonide (Nasacort Allergy 24 HR) and fluticasone propionate (Flonase Allergy Relief) are currently the only two INCS approved for nonprescription us

have minimal systemic absorption

Triamcinolone acetonide is approved for use in adults and children ages 2 years and older, whereas fluticasone propionate is approved for use in adults and children ages 4 years and older.

dosage of triamcinolone acetonide for children ages 2-5 years is 1 spray in each nostril daily (110 mcg/day)

Children ages 6-12 years should be started on the same dosage; if symptoms are not relieved, 2 sprays in each nostril daily (220 mcg/day) may be used.

The approved adult dosage is 220 mcg/day; once symptom control is achieved, some adults may be able to titrate down to 110 mcg/da

dosage of fluticasone propionate for children ages 4-11 years is 1 spray in each nostril daily (100 mcg/day). Adults and children ages 12 years and older should use 2 sprays in each nostril daily (200 mcg/day) for 1 week; if complete symptom control is achieved, they can titrate down to 1 spray in each nostril daily

Complete symptom control may not be seen for up to 1 week

Patients should be instructed to shake the bottle well before each use and discard the product after a total of 60 or 120 doses, depending on which size was purchased, even if the bottle does not feel completely empty.

Side effects are usually minor and include nasal discomfort, bleeding, or sneezing. More serious side effects include changes in vision, glaucoma, cataracts, increased risk of infection, and growth inhibition in

Antihistamines

sedating or non-sedating

Sedating antihistamines are highly lipophilic molecules that readily cross the blood-brain barrier. Nonsedating antihistamines, large protein-bound lipophobic molecules with charged side chains, do not readily cross the blood-brain barrier.

Most sedating antihistamines are well absorbed after oral administration with time to peak plasma concentrations in the range of 1.5-3 hours.

The nonsedating antihistamines are also rapidly absorbed after oral administration, with time to peak plasma concentrations in the range of 1-3 hours

systemic AH side effects:

primary adverse effects, CNS effects (depression and stimulation) and anticholinergic effects, are common with first-generation antihistamines but are rarely seen with second-generation agents. CNS-depressive effects include sedation and impaired performance (e.g., impaired driving performance, poor work performance, incoordination, reduced motor skills, and impaired information processing.) CNS-stimulatory effects include anxiety, hallucinations, appetite stimulation, muscle dyskinesias, and activation of epileptogenic foci.

Sedating antihistamines are contraindicated in newborns or premature infants, lactating women, and patients with narrow-angle glaucoma