• Allergy testing is rarely helpful in diagnosing allergic rhinitis but may be useful in patients with multiple allergen sensitivities. The goal of therapy is to relieve symptoms, and avoidance of allergens is the first step in this process.

• Controversy is ongoing regarding the use of medication vs. immunotherapy. Risk–cost analyses have not been performed; however, patients with moderate to severe perennial allergies may benefit most from immunotherapy.

• Patients with cough associated with viral respiratory infection can be treated with a first-generation antihistamine/decongestant combination preparation. Naproxen can also be used to help to decrease cough. Newer-generation, nonsedating antihistamines are ineffective in reducing cough and should not be used.

• Current recommendations have been revised to narrow recommended inhaled anticholinergic agents to a single drug, ipratropium bromide, for cough due to URI or bronchitis. The current guideline supports the use of codeine only in chronic bronchitis and not in cough due to URI. Peripheral and central cough suppressants have limited efficacy in cough due to URI. OTC combination cold medications, other than antihistamine/decongestant combinations, and preparations that contain zinc are not recommended for acute cough due to the common cold.

• These common drugs, which are widely available without prescription, are very effective in treating nasal congestion. Decongestants are sympathomimetic amines used to relieve nasal congestion caused by colds, allergies, and URIs; they also promote sinus drainage and relieve eustachian tube congestion. Oral forms are often used in combination with antihistamines and expectorants in both OTC and prescription doses (see Table 15-2). Topical nasal decongestants provide direct relief to swollen nasal membranes and sometimes are used to decrease congestion of the eustachian tube in middle ear infection and to relieve pressure and blockage of the ear during air travel. Decongestants should be used with caution in patients with hypertension, cardiovascular and peripheral vascular disease, hyperthyroidism, diabetes mellitus, prostatic hypertrophy, urinary retention, and increased intraocular pressure because of their sympathomimetic effects. They are contraindicated in patients with mitral valve prolapse and cardiac palpitations. They also have many side effects that can limit their use, particularly in the elderly.

• Oral decongestants generally do not cause sedation but may cause systemic effects, including nervousness, dizziness, and difficulty sleeping, particularly in infants and the elderly. The clinical problems most often seen with oral decongestants include tachycardia, nervousness, insomnia, palpitations, headache, and irritability, which may be poorly tolerated in the frail elderly; patients with poorly controlled hypertension may experience an increase in blood pressure. The provider should question the patient thoroughly about his history of decongestant use. Patients may voice complaints of their “heart racing,” or that the drug keeps them awake. Data suggest that oral decongestants may be used cautiously in patients with controlled hypertension. Sustained-release formulations may have less effect on the cardiovascular system. However, because they may antagonize the effects of antihypertensive medications, alternative agents such as topical decongestants should be used for these patients. The FDA has determined that the combination of pseudoephedrine and caffeine is not recognized as safe and effective for OTC use. Cough and cold formulations for children under the age of 6 are not recommended, and most manufacturers have removed these products from the market because of so many cases of accidental overdosing.

• Topical decongestants have little systemic effect, but because of rebound congestion (rhinitis medicamentosa), they should be used only in acute conditions for no longer than 3 consecutive days. Rebound congestion is treated by gradual withdrawal, one nare at a time. Saline nasal spray is often helpful. Overall, topical decongestants are more effective than oral ones, but oral decongestants have longer durations of action and are less irritating.

• Antihistamines are H₁-receptor antagonists that are often used alone or in combination with decongestants and expectorants to relieve symptoms associated with perennial and seasonal allergies with associated rhinitis, vasomotor rhinitis, allergic conjunctivitis, and cold symptoms such as sneezing and runny nose. They also are used to relieve allergic and nonallergic pruritic symptoms, to alleviate mild urticaria and angioedema, for prophylaxis against allergic reactions to blood or plasma products, and as adjunctive therapy in anaphylactic reactions Certain antihistamines also have antiemetic effects and are useful for nausea, vomiting, vertigo, and motion sickness.

• Many OTC cold remedies contain antihistamines; however, their use in the treatment of cold symptoms is controversial. Antihistamines are best used to treat allergic symptoms such as rhinorrhea; watery, itchy eyes; postnasal drainage; and sneezing. Decongestants are preferred for treatment of cold symptoms, such as nasal congestion caused by swollen nasal membranes.

• In general, antihistamines are not recommended to treat lower respiratory tract symptoms, including asthma, because some of their anticholinergic effects may cause thickening of respiratory secretions and may impair expectoration. Several evidence-based reports, however, indicate that antihistamines can be safely used in asthmatic patients with severe perennial allergies without exacerbating the asthma.

• Two generations of antihistamines are available. First-generation agents are usually available OTC and often are used before a health care provider is consulted. Most cause sedation and have sometimes been included in sleep aids. However, they remain highly effective in symptomatic treatment, and some products have been released (by prescription only) that provide new delivery systems that decrease drowsiness.

• Second-generation antihistamines are favored by clinicians for their efficacy/safety ratio and rapid onset of relief from sneezing, pruritus, and watery rhinorrhea. Most of these are now available OTC. All antihistamines are not very effective against nasal congestion and may even compound or contribute to its development. Local antihistamine nasal sprays and various ocular antihistamines are also effective in less than 30 minutes.

• OTC antihistamines that generally cause sedation may interfere with the patient’s activities and contribute to poor adherence. Therefore, an antihistamine and a decongestant often are combined to counteract the side effects of each drug while providing dual treatment. Sedating antihistamines are sometimes preferred if symptoms prevent patients from sleeping. Sedating antihistamines are also used in combination with analgesics as a pain reliever and sleep aid. Prescribed antihistamines are less likely to cause sedation and are generally well tolerated. If a particular antihistamine has lost effectiveness or causes untoward side effects, another antihistamine should be selected from a different class. If the patient requires two antihistamines for severe symptoms, drugs from two different classes should be selected.

• Cetirizine was recently put on the FDA drug watch list because of the incidence of oculogyric crisis.

• Intranasal corticosteroids are the most effective agents for the management of allergic rhinitis because of their direct reduction of nasal inflammation and their ability to reduce nasal hyperreactivity. All agents are safe and effective and will improve the patient’s quality of life if the patient uses them on a daily basis. Many patients do not like the odor or taste associated with specific agents, and one or two different medications may have to be tried before the most tolerable agent can be found for an individual. It is essential for the health care provider to help the patient understand the important role of these agents and to demonstrate how they should be administered correctly.

• Intranasal corticosteroids should be used for at least 1 month before it is decided whether they are effective. Patients should be warned that improvement usually does not begin until 1 to 2 weeks after therapy is started. Intranasal corticosteroids can be used with asthmatic patients and with those who have comorbid nasal polyposis. Intranasal steroids may help to shrink nasal polyps.

• Exceeding the recommended dose may result in systemic effects, including suppression of hypothalamic-pituitary-adrenal (HPA) axis function. Systemic effects are possible with inhaled steroids and are less likely with intranasal corticosteroids when used at conventional recommended doses.

• It should be noted that in some cases, oral corticosteroids may be required for a short time. These powerful drugs reduce nasal inflammation and hyperreactivity but have potentially serious side effects when used over a long period. A short course of tapered corticosteroids is advisable only for moderate to severe exacerbations of allergic rhinitis.