Safety of antihistamines in the treatment of allergic rhinitis in elderly patients

Using Patient Profiles To Guide The Choice Of Antihistamines In The Primary Care Setting In Malaysia: Expert Consensus And Recommendations

H1-antihistamines are recognized to be effective for conditions such as allergic rhinitis and chronic spontaneous urticaria. However, management of such conditions in the real-world primary care setting may be challenging due to diverse patient-specific considerations, the wide range of antihistamines available, choice of other treatment modalities, and the complexity of interpreting specialist treatment algorithms. Despite regular updates to international guidelines, regional/national surveys of healthcare professionals show a clear gap between guidelines and real-world practice, particularly at the primary care level. This article thus presents the consensus opinion of experts from relevant specialties in Malaysia - allergology, pediatrics, otorhinolaryngology, and dermtology - on harmonizing the use and choice of antihistamines in primary care. Patient profiling is recommended as a tool to guide primary care practitioners in prescribing the appropriate antihistamine for each patient. Patient profiling is a three-step approach that involves 1) identifying the individual's needs; 2) reviewing patient-specific considerations; and 3) monitoring treatment response and referral to specialists in more severe or difficult-to-treat cases. Concurrently, guidelct 3ines should be reviewed and updated periodically to include recommendations that are easily actionable for primary care practitioners.

Pharmacological Management of Allergic Rhinitis in the Elderly

Recent studies suggest that allergic rhinitis is highly prevalent in the elderly population, but is underdiagnosed and undertreated. This review article briefly introduces allergic rhinitis in the elderly (epidemiology and pathophysiology) and identifies the main goals of treatment in these patients with respect to age-related physiological factors, comorbid conditions and polypharmacy. The primary focus of the article is a narrative review of the literature concerning the different types of treatment options in elderly patients aged 60+ years (pharmacological therapy and allergen-specific immunotherapy). The main management trend for allergic rhinitis in elderly patients is the same as the trend in young patients. Second-generation antihistamines and nasal glucocorticosteroids are also the first-line therapies in seniors. In a few trials, allergen-specific immunotherapy for grass pollen or house dust mites has been shown to be effective and safe in patients aged 60 years or older with allergic rhinitis. In conclusion, undertreatment of allergic rhinitis in the elderly is a reality. Pharmacological treatment is quite similar in both older and younger patients with allergic rhinitis.

The role and choice criteria of antihistamines in allergy management - expert opinion

Allergic diseases are the most common chronic conditions lasting throughout the patient’s life. They not only cause significant deterioration in the quality of life of patients but also lead to significant absenteeism and reduced productivity, resulting in very high costs for society. Effective and safe treatment of allergic diseases is therefore one of the main challenges for public health and should be carried out by all the specialists in family medicine, internists and paediatricians in collaboration with allergists, otorhinolaryngologists and dermatologists. Antihistamines are most commonly used in the treatment of allergies. Several dozen drugs are available on the pharmaceutical market, and their generic forms are advertised widely as very effective drugs for the treatment of allergic diseases. What is the truth? What are the data from clinical trials and observational studies? Are all drugs equally effective and safe for the patient? According to a panel of experts representing various fields of medicine, inappropriate treatment of allergies can be very risky for patients, and seemingly equally acting medications may differ greatly. Therefore, a panel of experts gathered the latest data from the entire scientific literature and analysed the latest standards and recommendations prepared by scientific societies. This paper provides a summary of these studies and highlights the importance for the patient of the proper choice of drug to treat his allergies.

Rhinitis in the Elderly

By 2050, the US aging population will nearly double. It will be increasingly important for health care providers to diagnose and manage rhinitis. Nasal symptoms of rhinorrhea, congestion, sneezing, nasal/ocular pruritus, and postnasal drainage affect up to 32% of older adults, and can impact quality of life. Several underlying factors associated with aging may contribute to the pathogenesis of rhinitis in older adults. Although treatment options for rhinitis exist, special considerations need to be made because comorbidities, limited income, memory loss, and side effects of medications are common in older adults and may impact outcomes.

Elderly and drugs: risks and necessity of rational use

In recent decades, the world has undergone a demographic transformation with a rapid growth of the elderly population, resulting in an increased demand for funds to maintain their health and drug consumption. Pharmacokinetic and pharmacodynamic changes occurring in the elderly can interfere directly in the adverse effects of drugs and increase the risk of intoxication. In addition, there are external factors interfering with the pharmacotherapy of the elderly, such as inappropriate use and the lack of access to information. Many therapeutic classes of drugs should be used with caution or avoided in the elderly population, such as anti-inflammatory and some anti-hypertensive drugs, diuretics and digitalis. If not managed carefully, these medicines can affect the safety and quality of life in the elderly. Thus, the aim of this review was to identify drugs that should be used with caution in elderly patients in order to avoid intoxication and/or adverse drug events.

Rhinitis in the geriatric population

The current geriatric population in the United States accounts for approximately 12% of the total population and is projected to reach nearly 20% (71.5 million people) by 20301. With this expansion of the number of older adults, physicians will face the common complaint of rhinitis with increasing frequency. Nasal symptoms pose a significant burden on the health of older people and require attention to improve quality of life. Several mechanisms likely underlie the pathogenesis of rhinitis in these patients, including inflammatory conditions and the influence of aging on nasal physiology, with the potential for interaction between the two. Various treatments have been proposed to manage this condition; however, more work is needed to enhance our understanding of the pathophysiology of the various forms of geriatric rhinitis and to develop more effective therapies for this important patient population.

Complexities of diagnosis and treatment of allergic respiratory disease in the elderly

Atopic diseases such as rhinitis and asthma are relatively common in children and young adults. However, many patients aged >65 years are also affected by these disorders. Indeed, the literature suggests that between 3-12% and 4-13% of individuals in this age range have allergic rhinitis and asthma, respectively. However, these numbers are most likely underestimates because atopic diseases are frequently not considered in older patients. The diagnosis of both allergic rhinitis and asthma in older patients is more difficult than in younger patients because of a wide differential diagnosis of other diseases that can produce similar symptoms and must be excluded. Furthermore, treatment of these disorders is complicated by the potential for drug interactions, concern about the adverse effects of medications, in particular corticosteroids, and the lack of drug trials specifically targeting treatment of older patients with allergic rhinitis and asthma.

Allergic rhinitis: treatment based on patient profiles

Allergic rhinitis is a common medical condition characterized by nasal, throat, and ocular itching; rhinorrhea; sneezing; nasal congestion; and, less frequently, cough. The treatment of allergic rhinitis should control these symptoms without adversely affecting daily activities or cognitive performance and should prevent sequelae such as asthma exacerbation or sinusitis. This review describes a stepwise approach to treatment of allergic rhinitis derived from a synthesis of clinical trial results, patient preferences, and real-world tolerability data. Key clinical considerations include frequency and intensity of symptoms, patient age, comorbidities, compliance with treatment regimens (influenced by formulation, route and frequency of administration), and effects on quality of life. Oral second-generation antihistamines, versus first-generation agents and inhaled corticosteroids, should be considered first-line treatment because they provide rapid relief of most allergic rhinitis symptoms without safety and tolerability issues. Additional therapeutic agents can then be added or substituted based on individual symptom response.

Pharmacological management of allergic rhinitis in the elderly: safety issues with oral antihistamines

An increasing number of elderly persons in our society experience allergic rhinoconjunctivitis. Different agents are used in the pharmacological treatment of allergic rhinitis, with histamine H1 receptor antagonists (antihistamines) being the most frequently prescribed class. However, drug therapy of aged persons differs to a degree from that in other age groups primarily because of quantitative pharmacotherapeutic problems. The main problems are co-morbidities and polymedication, which may lead to drug-drug interactions. H1 receptor antagonists block the action of histamine at specific receptors and are available for both topical and systemic administration. First-generation H1 receptor antagonists are lipophilic and therefore may cross the blood-brain barrier; they also lack specificity for the H1 receptor. Second-generation H1 receptor antagonists have reduced capacity to cross the blood-brain barrier and greater specificity for the H1 receptor. Use of first-generation H1 receptor antagonists in the elderly should be considered carefully because of the large number of adverse effects and potential for interactions with these agents. Second-generation H1 receptor antagonists such as desloratadine, levocetirizine and ebastine provide good selective H1 receptor blockade without anticholinergic or alpha-adrenoceptor antagonist activity. Furthermore, they inhibit proinflammatory cytokines and are safe. Second-generation H1 receptor antagonists also offer therapeutic possibilities in patients with severe liver and/or renal dysfunction.

Acute Delirium Associated with Combined Diphenhydramine and Linezolid Use

OBJECTIVE:

To report a case of delirium with hallucinations presumably caused by the combination of diphenhydramine and linezolid.

CASE SUMMARY:

A 56-year-old white man was receiving diphenhydramine 300 mg/d for 2 days to treat pruritus caused by a bullous rash possibly induced by vancomycin. He subsequently developed visual and auditory hallucinations, with erratic, aggressive behavior persisting for 3 days. Central anticholinergic syndrome was first suspected, but the long duration and exaggerated response by a patient not prone to anticholinergic toxicity suggest that a second agent may have enhanced the reaction.

DISCUSSION:

The pharmacodynamic properties of linezolid make this drug a likely contributor to the marked, prolonged effects experienced by this patient. The Naranjo probability scale suggests a possible relationship between the reaction and the combination of diphenhydramine and linezolid.

CONCLUSIONS:

Drug-induced delirium can occur with several drugs, including diphenhydramine. Linezolid has dopaminergic properties that may enhance the central nervous system effects of anticholinergics. Precautionary monitoring of mental status should be advised when concomitantly administering linezolid with drugs in this class.

A new model of allergic rhinitis in rats by topical sensitization and evaluation of H(1)-receptor antagonists

An animal model of chronic allergic rhinitis was developed by repeated local booster sensitization into the nasal cavity in sensitized rats. The severity of allergic rhinitis was assessed by determining the extent of two markers of nasal allergic symptoms (sneezing and nasal rubbing) after antigen challenge. The number of incidents of sneezing and nasal rubbing was markedly increased during intranasal instillation of antigen in sensitized rats. The PCA titers were also markedly elevated by intranasal sensitization. Some histamine H(1)-receptor antagonists such as chlorpheniramine, ketotifen, astemizole and epinastine inhibited the increase in antigen-induced nasal symptoms in a dose-related manner. Nasal rubbing was more potently inhibited by H(1)-receptor antagonists than sneezing. In conclusion, we developed a chronic allergic rhinitis model showing nasal symptoms in rats, and this model may be useful for evaluating the effects of drugs on allergic rhinitis.

Pros and cons of the use of antihistamines in managing allergic rhinitis

Histamine H1 -receptor antagonists are generally considered first-line therapy for the management of allergic rhinitis. Other than histamine antagonism, several of the second-generation antihistamines have also shown inhibitory effects on chemical mediators of inflammation such as leukotrienes, prostaglandins, and kinins. This article reviews the pharmacology, clinical use, and side effect profiles of the commonly used H1 -receptor antagonists.