The choice of drugs for treatment of allergic rhinitis depends on the severity of symptoms and whether they are intermittent or persistent (see Table 1).

Patients with seasonal allergies often experience nasal itching and congestion, sneezing, rhinorrhea, and itchy, watery eyes. Oral, intranasal, and ophthalmic preparations are widely available over the counter (OTC) for relief of symptoms. Prescription products for management of allergic rhinitis and allergic conjunctivitis are reviewed separately.

In 2007, an FDA advisory committee asked that placebo-controlled, dose-ranging trials be conducted to establish the efficacy of the oral decongestant phenylephrine (Sudafed PE, and others), which is sold over the counter (OTC) as a single agent and in combination with other drugs for treatment of cold and allergy symptoms. Phenylephrine replaced pseudoephedrine (Sudafed, and others) in many OTC formulations when access to pseudoephedrine-containing products was restricted in an effort to reduce their use in the synthesis of methamphetamine.

CLINICAL STUDIES — In a randomized, open-label, dose-ranging trial in 539 patients with seasonal allergic rhinitis, phenylephrine doses up to four times the recommended dose of 10 mg were no more effective than placebo in reducing symptomatic nasal congestion.1 Other recent studies have also found oral phenylephrine no more effective than placebo in reducing nasal congestion.2-4

ALTERNATIVES – Oral pseudoephedrine reduces nasal congestion, but has no effect on other symptoms such as sneezing, itching, or rhinitis, and tolerance to its effects can occur with repeated use. Potential adverse effects include insomnia, excitability, headache, nervousness, anorexia, palpitations, tachycardia, arrhythmias, hypertension, nausea, vomiting, and urinary retention. Pseudoephedrine should be used cautiously in patients with cardiovascular disease, hypertension, diabetes, hyperthyroidism, narrow-angle glaucoma, or bladder neck obstruction.

Intranasal decongestants such as oxymetazoline (Afrin, and others) are effective and less likely than pseudoephedrine to cause systemic adverse effects, but they can cause stinging, burning, sneezing, dryness of the nose and throat, and, if used for more than 3-5 consecutive days, rebound congestion (rhinitis medicamentosa). Intranasal corticosteroids are the most effective drugs available for prevention and relief of nasal congestion and other seasonal allergic rhinitis symptoms.5

CONCLUSION — Oral phenylephrine is not effective for treatment of nasal congestion.

1. EO Meltzer et al. Oral phenylephrine HCl for nasal congestion in seasonal allergic rhinitis: a randomized, open-label, placebo-controlled study. J Allergy Clin Immunol Pract 2015; 3:702.
2. EO Meltzer at al. Phenylephrine hydrochloride modified-release tablets for nasal congestion: a randomized, placebo-controlled trial in allergic rhinitis patients. Ann Allergy Asthma Immunol 2015 November 7 (epub).
3. F Horak et al. A placebo-controlled study of the nasal decongestant effect of phenylephrine and pseudoephedrine in the Vienna Challenge Chamber. Ann Allergy Asthma Immunol 2009; 102:116.
4. JH Day et al. Efficacy of loratadine-montelukast on nasal congestion in patients with seasonal allergic rhinitis in an environmental exposure unit. Allergy Asthma Immunol 2009; 102:328.
5. Drugs for allergic disorders. Treat Guidel Med Lett 2013; 11:43.

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Concerns have surfaced again at the FDA and in the media about the safety of acetaminophen and the multiplicity of products on the market in the US that contain various amounts of it.

Many drugs can cause psychiatric symptoms, but a causal connection is often difficult to establish. Psychiatric symptoms that emerge during drug treatment could also be due to the underlying illness, previously unrecognized psychopathology, or psychosocial factors. The withdrawal of some drugs can cause symptoms such as anxiety, psychosis, delirium, agitation or depression.

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Allergic rhinitis, allergic conjunctivitis, atopic dermatitis, urticaria, anaphylaxis and asthma (reviewed in Treatment Guidelines 2005; 3:33 and not included here), are prevalent worldwide, especially in industrialized countries. Pharmacologic treatment of these disorders continues to improve in efficacy and safety. In addition to using drugs to prevent and control the symptoms of their allergic diseases, patients should also be instructed to avoid, if possible, specific allergens and/or environmental conditions that trigger or worsen their symptoms.

Allergic rhinitis, allergic conjunctivitis, atopic dermatitis, urticaria and anaphylaxis, along with asthma (reviewed in Treatment Guidelines 2002; 1:7 and not included here), have increased in prevalence during the past 30 years and are now epidemic worldwide, especially in industrialized countries. Many safe and effective drugs are currently available for prevention and relief of symptoms in these disorders, but pharmacological treatment alone may not be sufficient. Patients should also be instructed to avoid specific allergens or environmental conditions that trigger their symptoms. Allergen-specific immunotherapy, parenteral administration of gradually increasing doses of the allergen ("allergy shots"), has been effective in allergic rhinitis, allergic conjunctivitis and allergic asthma, and also in prevention of anaphylaxis triggered by stings from bees, yellow jackets, hornets and wasps. It has not been effective in food allergy, atopic dermatitis or urticaria.

An FDA panel has recommended that stronger warnings about hepatotoxicity be added to the labeling for acetaminophen (www.fda.gov, search "acetaminophen hepatotoxicity").

Many drugs can cause psychiatric symptoms, but a causal connection is often difficult to establish. Psychiatric symptoms that emerge during drug treatment may also be due to the underlying illness, previously unrecognized psychopathology, or psychosocial factors. The withdrawal of some drugs can cause symptoms such as anxiety, psychosis, delirium, agitation or depression.

The number of cough remedies available in the USA continues to multiply, but most products contain the same or similar ingredients in varying combinations. Most acute coughs do not require treatment with drugs, especially in children, and suppression of a productive cough may be harmful.

The US Food and Drug Administration has ordered removal of phenylpropanolamine from over-the-counter cold remedies and weight loss aids. The FDA based its decision on a recent study showing an increased risk of hemorrhagic stroke in young women taking the drug.

Acrivastine/Pseudoephedrine (Semprex-D) for Seasonal Allergic Rhinitis (Burroughs-Wellcome), a combination of acrivastine with pseudoephedrine hydrochloride, has been approved by the US Food and Drug Administration for treatment of seasonal allergic rhinitis. Acrivastine is a new H 1 -receptor antagonist with a chemical structure similar to that of triprolidine (Actidil, and others) (RN Brogden and D McTavish, Drugs, 41:927, 1991). Pseudoephedrine is an α -adrenergic agonist. The combination is available only by prescription.