Increased risk of serious injury following an initial prescription for diphenhydramine

Effect of Switching the Histamine-1 Receptor Antagonist Clemastine to Cetirizine in Paclitaxel Premedication Regimens: The H1-Switch Study

PURPOSE

Premedication, including a histamine-1 receptor (H1) antagonist, is recommended to all patients treated with paclitaxel chemotherapy to reduce the incidence of hypersensitivity reactions (HSRs). However, the scientific basis for this premedication is not robust, which provides opportunities for optimization. Substitution of intravenously administered first-generation H1 antagonist for orally administered second-generation H1 antagonist could reduce side effects, and improve efficiency and sustainability. This study investigates the efficacy and safety of substituting intravenous clemastine for oral cetirizine as prophylaxis for paclitaxel-induced HSRs.

METHODS

This single-center, prospective, noninferiority study compares a historic cohort receiving a premedication regimen with intravenous clemastine to a prospective cohort receiving oral cetirizine. Primary end point of the study is HSR grade ≥3. The difference in incidence was calculated together with the 90% CI. We determined that the two-sided 90% CI of HSR grade ≥3 incidence in the oral cetirizine cohort should not be more than 4% higher (ie, the noninferiority margin) compared with the intravenous clemastine cohort.

RESULTS

Two hundred and twelve patients were included in the oral cetirizine cohort (June 2022 and May 2023) and 183 in the intravenous clemastine cohort. HSR grade ≥3 incidence was 1.6% (n = 3) in the intravenous clemastine cohort and 0.5% (n = 1) in the oral cetirizine cohort, resulting in a difference of -1.2% (90% CI, -3.4 to 1.1).

CONCLUSION

Premedication containing oral cetirizine is as safe as premedication containing intravenous clemastine in preventing paclitaxel-induced HSR grade ≥3. These findings could contribute to optimization of care for patients and improve efficiency and sustainability.

Diphenhydramine: Time to Move on?

Diphenhydramine is one of the most widely available, longest-used antihistamine medications but has many side effects including sedation and risk of toxicity in overdose including cardiac toxicity. It is frequently inappropriately used when newer, more favorable antihistamine medications are available. Second-generation antihistamines are also widely available and affordable, with many of the same desired effects as diphenhydramine and fewer, if any, of the undesirable side effects. Because of the negative side effects and wide availability of alternative antihistamine medications, it is definitively time to move on from diphenhydramine.

Contemporary Role and Regulation of Over-the-Counter Sinonasal Medications

OBJECTIVE

Numerous pharmaceutical options are available over-the-counter (OTC) for the relief of sinonasal symptoms. Patients typically utilize these drugs in an unsupervised manner, without appreciation of their relative efficacy or potential for adverse effects. This review covers the scope and regulation of the OTC drug market, the pros and cons of OTC availability, and specific concerns that surround the most common classes of OTC sinonasal drugs. Suggestions are provided for the improvement of patient care and public health.

DATA SOURCES

MEDLINE publications and market reports.

REVIEW METHODS

Literature review.

CONCLUSIONS

Some of the most commonly used OTC sinonasal remedies, including decongestants and first-generation antihistamines, are less effective than alternative drugs and pose potential safety concerns.

IMPLICATIONS FOR PRACTICE

Clinicians should advocate to their patients for the appropriate use of alternative agents, such as intranasal corticosteroids and newer-generation antihistamines, and discourage the unsupervised use of oral and topical decongestants. Furthermore, health care practitioners should encourage dialogue with their patients about the use of OTC sinonasal remedies, with the goals of optimizing individual health and health care delivery.

Relation of Psychiatric Symptoms with Epilepsy, Asthma, and Allergy in Youth with ASD vs. Psychiatry Referrals

The present study aimed to characterize the association of psychopathology with the clinical correlates of epilepsy, asthma, and allergy within and between neurobehavioral syndromes. Participants were consecutively evaluated youth (6-18 years, 75 % male) with autism spectrum disorder (ASD; n = 589) and non-ASD outpatient psychiatry referrals (n = 653). Informants completed a background questionnaire (parents) and a psychiatric symptom severity rating scale (parents, teachers). Youth with ASD had higher rates of epilepsy and allergy but not asthma than psychiatry referrals, even when analyses were limited to youth with IQ ≥ 70. Somatic conditions evidenced variable associations with medical services utilization, educational interventions, family income, and maternal education. Youth with ASD with versus without epilepsy had more severe ASD social deficits (parents' ratings) and less severe ASD repetitive behaviors (teachers' ratings). Epilepsy was associated with more severe depression, mania, and schizophrenia symptoms in youth with ASD. Youth with allergy (psychiatry referrals only) had more severe anxiety and depression symptoms (parents' ratings) but less severe aggression (teachers' ratings) thus providing evidence of both context- and diagnostic-specificity. Youth with ASD versus non-ASD psychiatry referrals evidence a variable pattern of relations between somatic conditions and a range of clinical correlates, which suggests that the biologic substrates and psychosocial concomitants of neurodevelopmental disorders and their co-occurring somatic conditions may interact to produce unique clinical phenotypes.

An Analysis of the Inclusion of Medications Considered Potentially Inappropriate in Older Adults in Chemotherapy Templates for Hematologic Malignancies: One Recommendation for All?

BACKGROUND

There remains a paucity of data regarding the use of potentially inappropriate medications (PIMs) in the supportive management of older adults undergoing chemotherapy. Raising awareness among healthcare providers regarding the frequency of their use and potential toxicities may help to minimize the risks to patients.

OBJECTIVE

The aim of this study was to evaluate the frequency of six specific classes of medications considered PIMs by the American Geriatrics Society Beers Criteria that are commonly included in the National Comprehensive Cancer Network (NCCN) chemotherapy order templates for hematologic malignancies. The six PIMs evaluated are first-generation antihistamines, benzodiazepines, corticosteroids, H₂-receptor antagonists, metoclopramide, and antipsychotics.

METHODS

A total of 311 unique chemotherapy order templates published online by the NCCN for the treatment of hematologic malignancies were reviewed to determine the frequency that these six specific PIMs were recommended for supportive care.

RESULTS

Approximately 45% of the NCCN chemotherapy templates for hematologic malignancies specifically recommended the use of at least one of the six PIMs examined. The remainder of the templates evaluated referred exclusively to the NCCN Guidelines^® on Oncology for Antiemesis, which also included the use of at least one of the six PIMs evaluated.

CONCLUSIONS

These findings demonstrate that PIMs are frequently used as supportive therapy in the treatment of hematologic malignancies. Increasing healthcare provider awareness of their potential side effects may minimize the risks associated with their use in older adults with hematologic malignancies undergoing chemotherapy.

Comparison of the Effect of Two Kinds of Iranian Honey and Diphenhydramine on Nocturnal Cough and the Sleep Quality in Coughing Children and Their Parents

Coughing in a child induced by upper respiratory tract infections (URTIs) can be a problem, both for the child and its parents. Current studies show a lack of proven efficacy for over-the counter (OTC) medications, but promising data support the use of honey for children. The aim of this study was to compare the effects of two kinds of Iranian honey with diphenhydramine (DPH) on nocturnal pediatric coughs and the sleep quality of children and their parents. This was a clinical trial (registered in IRCT; No.: 28.20.7932, 15 October 2013). The study consisted of 87 patients. All the parents completed a standard previously validated questionnaire. The children were randomly assigned to one of three treatment groups: Group 1, Honey type 1 (Kimia Company, Iran) (n = 42), Group 2, Honey type 2 (Shahde-Golha, Iran) (n = 25), and Group 3, DPH (n = 20). Each group received double doses of the respective treatments on two successive nights. A second survey was then administered via a telephone interview in which the parents were asked the same questions. The mean scores for all aspects of coughs were significantly decreased in each group before and after the treatment. All three treatments improved the cough and sleep scores. Honey type 1 was superior to DPH in improving all aspects of coughs, except the frequency, and Honey type 2 was more effective than DPH in improving all aspects of coughs, except the sleep quality of the child. There was no significant difference between Honey type 1 and 2 in any aspects of cough relief in the present study. The results suggest that honey may provide better cough relief than DPH in children and improve the sleep quality of children and their parents.

Association between childhood allergic disease, psychological comorbidity, and injury requiring medical attention

BACKGROUND

Children with allergic disease have multiple risk factors for accidental injuries.

OBJECTIVE

To determine the prevalence of injuries requiring medical treatment in US children with allergic disease.

METHODS

The authors analyzed data from the 2007 to 2008 National Survey of Children's Health, including a nationally representative sample of 27,556 children 0 to 5 years old.

RESULTS

The prevalence (95% confidence interval [CI]) of at least 1 allergic disease was 29.4% (28.0-30.8); 6.6% (5.8-7.4) were diagnosed with asthma, 15.0% (14.0-16.0) with eczema, 11.6% (10.6-12.6) with hay fever, and 6.1% (5.4-6.9) with food allergy. Children with allergic disorders had higher odds of at least 1 comorbid psychiatric and behavioral disorder (PBD; survey logistic regression; odds ratio 2.93, 95% CI 2.13-4.03), including attention-deficit/hyperactivity disorder (4.75, 2.89-7.80), depression (6.03, 1.29-28.27), anxiety (5.54, 2.70-11.37), conduct/oppositional defiant disorder (2.97, 1.88-4.70), and learning delay (2.49, 1.70-3.66), but not autism/Asperger disorder (1.89, 0.98-3.64). The prevalence of injury in the past year requiring medical attention was 10.5% (95% CI 9.5-11.4). The association between allergic disease and injury requiring medical attention was mediated in part by a PBD (Sobel test 0.0021, 95% CI 0.0014-0.0029, P < .0001; bootstrapping approach, indirect effects, odds ratio 1.005, 95% CI 1.003-1.007; Baron-Kenny β(yx,m) = 0.04, P < .0001, R(2) = 0.002). However, children with at least 1 allergic disorder (1.74, 1.23-2.46), including eczema (1.59, 1.01-2.50), asthma (1.91, 1.10-3.31), hay fever (2.05, 1.24-3.39), and food allergies (2.00, 1.10-3.67), had higher odds of sustaining injuries even after controlling for comorbid PBDs and medical disorders.

CONCLUSION

The results suggest that the association between allergic disease and injury is multifactorial, including being secondary to PBD.

A comparison of the effect of honey, dextromethorphan, and diphenhydramine on nightly cough and sleep quality in children and their parents

OBJECTIVES

Coughing is a prevalent symptom of upper respiratory infections (URIs) that cause disturbance in the sleep of children and their parents. There is as yet no reliable treatment to control URIs and their related cough; however, drugs such as dextromethorphan (DM) and diphenhydramine (DPH) are now mainly used in the world. The aim of this study is to compare the effect of honey, DM, and DPH on the nightly cough and sleep quality of children and their parents.

DESIGN

This was a clinical trial study in which 139 children aged 24-60 months suffering from coughing due to URIs were selected and assigned randomly to 4 groups. The first group received honey (HG), the second one DM (DMG), the third DPH (DPHG), but the fourth group or control group (CG) was assigned to a supportive treatment.

OUTCOME MEASURES

After approximately a 24-hour intervention, the 4 groups were reexamined and their cough frequency, cough severity, and sleep quality in children and their parents were recorded by using the questionnaire with Likert-type questions.

RESULTS

The mean of cough frequency score HG is 4.09 +/- 0.72 and 1.93 +/- 0.65 before and after the intervention, respectively, while these figures for the CG are 4.11 +/- 0.78 and 3.11 +/- 0.57, respectively. After the intervention, the difference of the mean score of the variables in all groups became statistically significant. The mean score of all variables in HG has stood significantly higher than those in other groups. There is also a significant relationship between the DMG and CG groups, even though there is no statistically difference between DMG and DPHG groups.

CONCLUSIONS

The result of the study demonstrated that receiving a 2.5-mL dose of honey before sleep has a more alleviating effect on URIs-induced cough compared with DM and DPH doses.

Risk of first-generation H(1)-antihistamines: a GA(2)LEN position paper

BACKGROUND

First-generation H(1)-antihistamines obtained without prescription are the most frequent form of self-medication for allergic diseases, coughs and colds and insomnia even though they have potentially dangerous unwanted effects which are not recognized by the general public.

AIMS

To increase consumer protection by bringing to the attention of regulatory authorities, physicians and the general public the potential dangers of the indiscriminate use first-generation H(1)-antihistamines purchased over-the counter in the absence of appropriate medical supervision.

METHODS

A GA(2)LEN (Global Allergy and Asthma European Network) task force assessed the unwanted side-effects and potential dangers of first-generation H1-antihistamines by reviewing the literature (Medline and Embase) and performing a media audit of US coverage from 1996 to 2008 of accidents and fatal adverse events in which these drugs were implicated.

RESULTS

First-generation H(1)-antihistamines, all of which are sedating, are generally regarded as safe by laypersons and healthcare professionals because of their long-standing use. However, they reduce rapid eye movement (REM)-sleep, impair learning and reduce work efficiency. They are implicated in civil aviation, motor vehicle and boating accidents, deaths as a result of accidental or intentional overdosing in infants and young children and suicide in teenagers and adults. Some exhibit cardiotoxicity in overdose.

CONCLUSIONS

This review raises the issue of better consumer protection by recommending that older first-generation H(1)-antihistamines should no longer be available over-the-counter as prescription- free drugs for self-medication of allergic and other diseases now that newer second- generation nonsedating H(1)-antihistamines with superior risk/benefit ratios are widely available at competitive prices.

The use of electronic pharmacy data to investigate prescribed medications and fatal motor vehicle crashes in a military population, 2002-2006

The authors examined the association between prescribed medications and fatal motor vehicle crashes (MVCs) in an active duty military population between 2002 and 2006. Using a case-control design, MVC deaths were ascertained using a military mortality registry, and an integrated health system database provided information on health system eligibility, pharmacy transactions, and medical encounters. Cases and controls were matched on comparable observation time outside periods of deployment. Among selected categories, only one, antidepressant medications, was an independent predictor of fatal MVC (odds ratio, 3.19; 95% confidence interval, 1.01-10.07). Male gender, Black race, enlisted rank, service branch (Navy and Marine Corps), and selected co-morbidities were also independent predictors. Unexpectedly, the odds of younger age quartiles (< 27 years) and history of deployment were reduced for MVC cases. Although results need to be considered in the context of data limitations, the association between prescribed antidepressants and fatal MVC may reflect unmeasured co-morbidities, such as combined effects of prescribed and over-the-counter medications and/or alcohol or other substance abuse. Younger individuals, representing new military accessions in training or returning from deployment with serious injuries, may have fewer opportunities to operate vehicles, or targeted efforts to reduce MVC following deployment may be showing a positive effect.

Time-dependent inhibition of histamine-induced cutaneous responses by oral and intramuscular diphenhydramine and oral fexofenadine

BACKGROUND

Diphenhydramine is often the treatment of choice for acute urticarial or allergic reactions despite its adverse effects of sedation and impairment. Second- and third-generation histamine1-antihistamines are generally devoid of these adverse effects but are typically not used because of a perceived slower onset of action.

OBJECTIVE

To examine the time-dependent effects of oral fexofenadine and oral and intramuscular diphenhydramine to reduce histamine-induced wheal-and-flare responses.

METHODS

Eighteen healthy patients were included in a double-blind, placebo-controlled, 3-way, randomized, crossover study with oral fexofenadine (180 mg) and oral and intramuscular diphenhydramine (50 mg). Histamine-induced skin tests were performed before and more than 6 hours subsequent to dosing. The primary end point was time to induce a 50% reduction in histamine-induced flare. Secondary end points included change from baseline at each time point in wheal-and-flare responses and area under the curve at more than 6 hours for flare.

RESULTS

No significant differences were found in the 50% inhibitory responses of histamine-induced flares among the 3 groups (P = .09). No significant differences were found among the 3 groups in change from baseline at each time point except for 30 minutes during which fexofenadine had no inhibitory effect. Area under the curve analyses for wheal-and-flare responses revealed no differences among treatments at more than 6 hours.

CONCLUSION

Diphenhydramine tended to work more rapidly than fexofenadine, but the differences were not statistically significant. Given the adverse effect profile of diphenhydramine, but only marginal onset of action advantage, the risk-to-benefit ratio may be more favorable for oral fexofenadine when treating an acute urticarial or allergic reaction.

Identification and management of undiagnosed and undertreated allergic rhinitis in adults and children

Allergic rhinitis (AR) is a common health problem that affects adults, adolescents and children and is often undiagnosed or inadequately treated. Because AR is not a life-threatening disease, many patients do not seek medical treatment for their symptoms, and others self-medicate with over-the-counter medications, often sedating antihistamines. However, untreated or inadequately treated AR can substantially impair overall quality of life (QOL) by causing fatigue, headache, cognitive impairment and other problems. The risk for comorbid conditions, such as asthma, otitis media, and lymphoid hypertrophy with obstructive sleep apnea, can increase, and the symptoms of AR can worsen if AR is not adequately treated. Among the symptoms of AR, nasal congestion has been described by patients as the most bothersome because it disrupts sleep, resulting in diminished daytime performance. A new congestion screening tool, the Congestion Quantifier, has been developed to aid in the diagnosis and treatment of AR and to help guide treatment decisions. Intranasal corticosteroids (INSs) are recommended as effective pharmaceutical treatments for controlling the symptoms of AR. Randomized, controlled trials in children and adults have demonstrated that INSs relieve rhinitis symptoms, thereby improving QOL in individuals with seasonal or perennial AR. Most INSs are approved for use in children >or=6 years of age, but mometasone furoate and fluticasone furoate are approved for use in children as young as 2 years of age and fluticasone propionate for children >or=4 years old. Long-term benefits have also been seen with the use of immunotherapy, although some patients, especially children, resist the injections used in subcutaneous immunotherapy. Recent studies with sublingual immunotherapy have indicated that it might be an effective and well-tolerated alternative to immunotherapy injections.

Current assessment of risk-benefit by regulators: is it time to introduce decision analyses?

Regulatory risk-benefit assessments may overweight small but serious risks relative to benefits. Using terfenadine and torsade de pointes as an exemplar, we illustrate how a different decision may result when outcomes are assessed using quality-adjusted life-years within a decision-analytical framework. The adoption of common measures of health outcome and the use of decision analyses, which will allow uncertainty to be characterized and evidence to be compiled from disparate sources, may inform complex risk-benefit decisions and should be used in conjunction with qualitative assessments.

Safety of levocetirizine treatment in young atopic children: An 18-month study

There are more than 40 H(1)-antihistamines available worldwide. Most of these medications have never been optimally studied in prospective, randomized, double-masked, placebo-controlled trials in children. The aim was to perform a long-term study of levocetirizine safety in young atopic children. In the randomized, double-masked Early Prevention of Asthma in Atopic Children Study, 510 atopic children who were age 12-24 months at entry received either levocetirizine 0.125 mg/kg or placebo twice daily for 18 months. Safety was assessed by: reporting of adverse events, numbers of children discontinuing the study because of adverse events, height and body mass measurements, assessment of developmental milestones, and hematology and biochemistry tests. The population evaluated for safety consisted of 255 children given levocetirizine and 255 children given placebo. The treatment groups were similar demographically, and with regard to number of children with: one or more adverse events (levocetirizine, 96.9%; placebo, 95.7%); serious adverse events (levocetirizine, 12.2%; placebo, 14.5%); medication-attributed adverse events (levocetirizine, 5.1%; placebo, 6.3%); and adverse events that led to permanent discontinuation of study medication (levocetirizine, 2.0%; placebo, 1.2%). The most frequent adverse events related to: upper respiratory tract infections, transient gastroenteritis symptoms, or exacerbations of allergic diseases. There were no significant differences between the treatment groups in height, mass, attainment of developmental milestones, and hematology and biochemistry tests. The long-term safety of levocetirizine has been confirmed in young atopic children.

Caring for patients with allergic rhinitis

PURPOSE

Allergic rhinitis (AR) affects up to 40 million Americans, with an estimated cost of $2.7 billion per annum. This review discusses several therapeutic options that reduce the symptoms of AR, including allergen avoidance, antihistamines, intranasal corticosteroids (INS), leukotriene receptor antagonists, and immunotherapy.

DATA SOURCES

The articles included in this review were retrieved by a search of Medline literature on the subjects of AR, antihistamines, INS, leukotriene antagonists, and immunotherapy, as well as current published guidelines for the treatment of AR.

CONCLUSIONS

Allergen avoidance is recommended for all patients prior to pharmacologic therapy. Oral and nasal H(1)-antihistamines are recommended to alleviate the mild and intermittent symptoms of AR, and INS are recommended as the first-line treatment choice for mild persistent and more moderate-to-severe persistent AR.

IMPLICATIONS FOR PRACTICE

There are a number of different types of therapy for the management of AR; with so many options available, successful tailoring of treatment to suit individual requirements is realistically achievable.

Acetaminophen and diphenhydramine premedication for allergic and febrile nonhemolytic transfusion reactions: good prophylaxis or bad practice?

Febrile nonhemolytic and allergic reactions are the most common transfusion reactions, but usually do not cause significant morbidity. In an attempt to prevent these reactions, US physicians prescribe acetaminophen or diphenhydramine premedication before more than 50% of blood component transfusions. Acetaminophen and diphenhydramine are effective therapies for fever and allergy, respectively, so their use in transfusion has some biologic rationale. However, these medications also have potential toxicity, particularly in ill patients, and in the studies performed to date, they have failed to prevent transfusion reactions. Whether the benefits of routine prophylaxis with acetaminophen and diphenhydramine outweigh their risks and cost requires reexamination, particularly in light of the low reaction rates reported at many institutions even when premedication is not prescribed.

Impact of CYP2D6*10 on H1-antihistamine-induced hypersomnia

OBJECTIVE

This study investigated the relevance of the cytochrome P450 (CYP) 2D6 genotype to the adverse drug reactions (ADRs) of H1-antihistamines and the level of sedation.

METHODS

Japanese participants in a health screening program were asked to describe any past history of ADRs. Any subjects reporting ADRs induced by H1-antihistamines were then individually interviewed and defined as cases. Excessive daytime sleepiness, which had occurred in the cases as an H1-antihistamine-induced ADR, was assessed by the Epworth sleepiness scale (ESS), and an ESS score >or=12 was considered hypersomnia. CYP2D6*4, *5, *14, and *10 were genotyped by a panel of polymerase chain reaction techniques.

RESULTS

Out of 2,074 participants, 100 cases (M:F = 37:63, mean age 51.9 +/- 9.2 years) were eligible for analysis. The most common etiological drug was chlorpheniramine, which is the most frequently used H1-antihistamine in Japan. CYP2D6*10 allele and genotypes were more frequently found in the cases than in the healthy Japanese population in a large study (P < 0.005 and P = 0.039, respectively), but no difference was observed in the null alleles and genotypes. The ESS scores in 75 cases (M:F=25:50) who had experienced excessive daytime sleepiness were 9.5 +/- 5.5 in men and 12.9 +/- 6.1 in women (P < 0.001, cases vs. 34 subjects without symptoms; P = 0.001 men vs. women). The occurrence of hypersomnia increased as the number of CYP2D6 mutant alleles increased (P = 0.045).

CONCLUSION

The results suggest that the presence of the CYP2D6*10 allele is a risk factor for development of H1-antihistamine-induced ADRs in Japanese.

Management of Seasonal Allergic Rhinitis: Comparative Efficacy of the Newer-Generation Prescription Antihistamines

PURPOSE

To discuss the efficacy and safety of second-generation prescription antihistamines, cetirizine, desloratadine, and fexofenadine, and to inform nurse practitioners (NP) who are in a position to optimally manage patients presenting with seasonal allergic rhinitis (SAR).

DATA SOURCES

Selected published clinical trials.

CONCLUSIONS

NP, who are ideally placed to successfully manage the majority of patients with SAR, should be fully aware of the treatment options available. Although first-generation over-the-counter antihistamines are convenient to use and are readily accessible, patients run the risk of experiencing adverse effects, such as sedation. For this reason, second-generation antihistamines should be considered a better alternative; however, they need to be evaluated individually on the basis of their proven efficacy and safety. Both cetirizine and fexofenadine are equally effective at relieving the symptoms of SAR; however, cetirizine has been shown to be more likely to cause sedation and impairment.

IMPLICATIONS FOR PRACTICE

If left untreated, SAR can have a substantial effect on patients' quality of life, resulting in fatigue, irritability, sleep disorders, and cognitive impairment.

Cost and utilization impacts of oral antihistamines in the California Medi-Cal program

OBJECTIVES

Newer oral allergic rhinitis (AR) medications, the second-generation antihistamines (SGAs) have gained widespread acceptance because of their efficacy and reduced side effects relative to first-generation antihistamines (FGAs). There are no empirical studies comparing the costs of treatment of SGAs relative to FGAs.

METHODS

We analyzed data from a 20% beneficiary sample (approximately 120,000 continuously enrolled beneficiaries per year) for the Medi-Cal Fee-for-Service program during 1999 to 2000. AR medications available under Medi-Cal included three SGA medications (loratadine, fexofenadine, and cetirizine) and over 200 FGA products containing either diphenhydramine or chlorpheniramine or both. Because multiple medications were evaluated, a sample selection model was estimated using a two-stage multinomial logistic--variance components regression framework.

RESULTS

SGA medications have significantly lower total direct health-care treatment costs per patient than FGA medications with costs ranging from US 347 dollars to US 448 dollars less (P < 0.001), despite higher AR medication costs. Total drug expenditures were also not significantly different for patients using SGA or FGA medications despite SGA prescriptions averaging US 47 dollars higher than FGAs. Emergency department visits, inpatient admissions and physician office visits were also significantly lower for patients using SGA medications.

CONCLUSIONS

Significant cost and utilization reductions were associated with all of the SGA medications relative to FGA drugs, despite their higher acquisition costs. If facing higher copayments for prescription AR drugs, many patients, particularly lower income patients, may choose cheaper over-the-counter (OTC) FGAs rather than SGAs. Our analysis finds this might lead to increased overall health-care treatment costs, unless Medicaid and health insurance plans subsidize OTC AR medications.

Second-Generation Antihistamines

Antihistamines are useful medications for the treatment of a variety of allergic disorders. Second-generation antihistamines avidly and selectively bind to peripheral histamine H1 receptors and, consequently, provide gratifying relief of histamine-mediated symptoms in a majority of atopic patients. This tight receptor specificity additionally leads to few effects on other neuronal or hormonal systems, with the result that adverse effects associated with these medications, with the exception of noticeable sedation in about 10% of cetirizine-treated patients, resemble those of placebo overall. Similarly, serious adverse drug reactions and interactions are uncommon with these medicines. Therapeutic interchange to one of the available second-generation antihistamines is a reasonable approach to limiting an institutional formulary, and adoption of such a policy has proven capable of creating substantial cost savings. Differences in overall efficacy and safety between available second-generation antihistamines, when administered in equivalent dosages, are not large. However, among the antihistamines presently available, fexofenadine may offer the best overall balance of effectiveness and safety, and this agent is an appropriate selection for initial or switch therapy for most patients with mild or moderate allergic symptoms. Cetirizine is the most potent antihistamine available and has been subjected to more clinical study than any other. This agent is appropriate for patients proven unresponsive to other antihistamines and for those with the most severe symptoms who might benefit from antihistamine treatment of the highest potency that can be dose-titrated up to maximal intensity.

The economic impact of payer policies after the Rx-to-OTC switch of second-generation antihistamines

OBJECTIVE

As a result of the over-the-counter (OTC) introduction of loratadine, health plans have been struggling to determine the best policy to incorporate this change within their existing drug benefit structure for second-generation antihistamines (SGA). The objective of this study was to examine the economic impact of payer policies in response to the Rx-to-OTC switch of loratadine.

STUDY DESIGN

Decision analysis was used to model the budgetary impact and cost-effectiveness of four policies for SGA benefits for the managed care organization (MCO), employer, and Medicaid perspectives separately.

PATIENTS AND METHODS

Outcomes included direct medical costs and lost productivity (employers only), discounted, quality-adjusted life-years (QALYs) saved because of amelioration of allergic rhinitis symptoms and avoidance of unintentional injuries associated with the use of first-generation antihistamines (FGA). Bayesian probabilistic sensitivity analysis was conducted using second-order Monte Carlo simulation.

RESULTS

Providing limited OTC and second-tier prescription benefits would cost approximately 0.13 dollars and 0.30 dollars compared to third-tier prescription benefits for employers and MCOs, respectively, and would save Medicaid 0.02 dollars per member per month (PMPM). Providing limited coverage for OTC loratadine while retaining second-tier prescription benefits for SGA was the optimal policy for a willingness to pay below 26,200 dollars per QALY for all payers.

CONCLUSIONS

Offering second-tier prescription and limited OTC benefits provides greater effectiveness and is not significantly more expensive PMPM than discontinuation. Some of the drug savings from limiting coverage of prescription SGA may be attenuated by the cost of lost productivity and direct medical expenditures due to unintentional injuries associated with increased FGA use in addition to the increased cost of therapeutic substitutes.

Effect of dextromethorphan, diphenhydramine, and placebo on nocturnal cough and sleep quality for coughing children and their parents

OBJECTIVES

To determine whether the commonly used over-the-counter medications dextromethorphan and diphenhydramine are superior to placebo for the treatment of nocturnal cough and sleep difficulty associated with upper respiratory infections and to determine whether parents have improved sleep quality when their children receive the medications when compared with placebo.

METHODS

Parents of 100 children with upper respiratory infections were questioned to assess the frequency, severity, and bothersome nature of the nocturnal cough. Their answers were recorded on 2 consecutive days, initially on the day of presentation, when no medication had been given the previous evening, and then again on the subsequent day, when either medication or placebo was given before bedtime. Sleep quality for both the child and the parent were also assessed for both nights.

RESULTS

For the entire cohort, all outcomes were significantly improved on the second night of the study when either medication or placebo was given. However, neither diphenhydramine nor dextromethorphan produced a superior benefit when compared with placebo for any of the outcomes studied. Insomnia was reported more frequently in those who were given dextromethorphan, and drowsiness was reported more commonly in those who were given diphenhydramine.

CONCLUSIONS

Diphenhydramine and dextromethorphan are not superior to placebo in providing nocturnal symptom relief for children with cough and sleep difficulty as a result of an upper respiratory infection. Furthermore, the medications given to children do not result in improved quality of sleep for their parents when compared with placebo. Each clinician should consider these findings, the potential for adverse effects, and the individual and cumulative costs of the drugs before recommending them to families.

Cost-benefit analysis of first-generation antihistamines in the treatment of allergic rhinitis

BACKGROUND

The majority of individuals with allergic rhinitis in the US take first-generation antihistamines (FGAs). Although FGAs have been proven effective in alleviating allergic rhinitis symptoms, they have been associated with an increased risk of motor vehicle, aviation and occupational injuries and deaths, reduced productivity and impaired learning.

OBJECTIVE

The objective of this analysis was to quantify the total costs and benefits of FGA use in the US from the societal perspective.

METHODS

We used a decision-analytic model to quantify the annual societal costs and benefits of treatment with FGAs compared with the hypothetical alternative of no treatment for the population of individuals with allergic rhinitis and taking FGAs in the US in 2001. The benefit associated with FGA use was estimated using the willingness-to-pay framework and projected to the US population using published estimates of the prevalence of allergic rhinitis. The costs of FGA-associated sedation included lost productivity and the direct and indirect cost of unintentional injuries (including motor vehicle, occupational, public and home injuries and fatalities). The incidence of injuries and fatalities associated with FGA use was estimated using the risk of injury attributable to the sedentary effects of FGAs in the allergic rhinitis population. To evaluate uncertainty in the model assumptions, a probabilistic sensitivity analysis was conducted using Bayesian second-order Monte Carlo simulation. Costs and benefits are expressed in 2001 US dollars, using a 3% discount rate.

RESULTS

Based on current utilisation, the total societal benefit (95% credible interval) associated with the use of FGAs for the treatment of allergic rhinitis was US 7.7 billion dollars (US 1.3 billion dollars to US 21 billion dollars). The societal cost of purchasing FGAs was only US 697 million dollars. However, the societal cost of FGA-associated sedation was US 11.3 billion dollars (US 2.4 billion dollars to US 50.8 billion dollars). The annual societal net benefit of FGA use for the treatment of allergic rhinitis in the US was -US4.2 billion dollars (-US 36 billion dollars to +US 0.296 billion dollars). The net benefit was negative in 97% of the 10,000 Monte Carlo simulations.

CONCLUSIONS

The societal benefits of FGA use in alleviating the symptoms of allergic rhinitis are significant. However, based on the assumptions, probability distributions and parameter estimate ranges used in the current model, it is very likely that the costs associated with sedation exceed the benefits of FGA use in the US. The cost of FGA-associated sedation is comparable to estimates of the cost of all medical care expenditures on respiratory conditions in the US (US 12.1 billion dollars to US 31.3 billion dollars) [1996 values] and provides compelling evidence of the economic burden of sedation associated with FGA use.

Transitioning the Second-Generation Antihistamines to Over-the-Counter Status

BACKGROUND

A U.S. Food and Drug Administration advisory committee deemed the second-generation antihistamines (SGA) safe for over-the-counter use against the preliminary opposition of the manufacturers. As a result, loratadine is now available over-the-counter. First-generation antihistamines (FGA) are associated with an increased risk of unintentional injuries, fatalities, and reduced productivity. Access to SGA over-the-counter could result in decreased use of FGA, thereby reducing deleterious outcomes. The societal impact of transitioning this class of medications from prescription to over-the-counter status has important policy implications.

OBJECTIVE

To examine the cost-effectiveness of transitioning SGA to over-the-counter status from a societal perspective.

RESEARCH DESIGN

A simulation model of the decision to transition SGA to over-the-counter status was compared with retaining prescription-only status for a hypothetical cohort of individuals with allergic rhinitis in the United States. Estimates of costs and effectiveness were obtained from the medical literature and national surveys. Sensitivity analysis was performed using a second-order Monte Carlo simulation.

MAIN OUTCOME MEASURES

Discounted, quality-adjusted life-years saved as a result of amelioration of allergic rhinitis symptoms and avoidance of motor vehicle, occupational, public and home injuries and fatalities; discounted direct and indirect costs.

RESULTS

Availability of SGA over-the-counter was associated with annual savings of 4 billion dollars (2.4-5.3 billion dollars) or 100 dollars (64-137 dollars) per allergic rhinitis sufferer and 135,061 time-discounted quality-adjusted life years (84,913-191,802). The sensitivity analysis provides evidence in support of these results.

CONCLUSION

Making SGA available over-the-counter is both cost-saving and more effective for society, largely as a result of reduced adverse outcomes associated with FGA-induced sedation. Further study is needed to determine the differential impact on specific vulnerable populations.

Antihistamines

Antihistamines and their drug-drug interactions are reviewed in depth. The metabolism of "classic" or sedating antihistamines is coming to light through in vivo and in vitro studies. The polymorphic CYP 2D6 metabolic enzyme appears to be potently inhibited by many of these over-the-counter medications. The history of the discontinued "second-generation" antihistamines terfenadine and astemizole is reviewed to remind the reader why the understanding of the cytochrome P450 system became increasingly important when the cardiotoxicity of these drugs became apparent. The "third-generation" nonsedating antihistamines are also listed and compared. They have been exhaustively scrutinized for drug-drug interactions and cardiotoxicity, and they appear to have no serious drug-drug interactions at recommended doses.

First do no harm: managing antihistamine impairment in patients with allergic rhinitis

Antihistamines are effective medications that have been used for decades in the management of allergic rhinitis; however, they may be administered or selected in an inappropriate fashion and may be the source of drug-related morbidity. Our objective is to present relevant background information and an expert consensus statement on the use of antihistamines in treatment of allergic rhinitis. In July 2002, 14 experts in allergy, clinical immunology, pharmacology, and impairment assessment were invited to participate in a roundtable conference to present current concepts and develop a consensus statement on the clinical management of allergic rhinitis with antihistamines. Many of the antihistamines used to treat allergic rhinitis, as well as the disease itself, may produce sedation, impairment, and reduced quality of life. Allergic rhinitis is more appropriately managed with the relatively nonimpairing second-generation antihistamines (eg, loratadine, desloratadine, cetirizine, and fexofenadine), because older agents (eg, diphenhydramine, chlorpheniramine, and brompheniramine) produce sedation and impairment and worsen sleep architecture. Although there is some debate surrounding the varying degrees of efficacy of second-generation antihistamines, it is known that some agents may produce varying levels of drowsiness or impairment, especially at higher than recommended doses. The differences with regard to safety among the second-generation antihistamines are smaller than are the differences between the first and second generations. A nonsedating, nonimpairing (even at higher than recommended doses), second-generation antihistamine is preferred for all patients, particularly those with a higher risk for the development of adverse effects. We recommend that primary care and specialist physicians, nurse practitioners, physician assistants, pharmacists, and all other health professionals involved in the diagnosis and treatment of allergic rhinitis follow this consensus document and share this information with patients for whom antihistamine therapy is recommended. In addition, further epidemiologic studies on the effects of antihistamines should be performed.