A Canadian multicenter study with Zaditen (ketotifen) in the treatment of bronchial asthma in children aged 5 to 17 years

Comparative clinical evaluation of ketotifen and montelukast sodium in asthmatic Iraqi patients

Asthma is a common and chronic inflammatory condition of the airways whose cause is not completely understood. Although many classes of drugs are used for management of asthma, the response is variable due to multifactor reasons. This study was designed to evaluate the outcome of using ketotifen or montelukast sodium in Iraqi asthmatic patients. Single blinded randomized clinical trial was utilized, in which 100 asthmatic patients were recruited from Al-Karama hospital and randomized into two groups; 1st group (50 patients, treated with ketotifen for 4 weeks) and 2nd group (50 patients treated with montelukast sodium for 4 weeks). Asthma symptom score and wheezing were recorded at the beginning (first visit) and at the end of the study (after one month). Pulmonary function tests (PFTs) were performed by spirometry, and the patients' use of asthma drugs and their symptoms were evaluated at each visit. The result showed that asthma symptom, chest wheezing, and PFT values were significantly improved in the two groups at the end of the study compared to first visit (p < 0.05). All symptoms were significantly lower and PFT values were higher in the 2nd group compared to 1st group (p < 0.05). In conclusion, both ketotifen and montelukast sodium showed significant changes in asthma symptoms and PFT after one month of treatment, but the changes were more significant with montelukast group (2nd group) compared with ketotifen group (1st group) and this indicate that montelukast was more effective than ketotifen in treatment of asthmatic patients.

Asthma

Asthma has been recognized as a disease since the earliest times. In the Corpus Hippocraticum, Hippocrates used the term “ασθμα” to indicate any form of breathing difficulty manifesting itself by panting. Aretaeus of Cappadocia, a well-known Greek physician (second century A.D.), is credited with providing the first detailed description of an asthma attack [13], and to Celsus it was a disease with wheezing and noisy, violent breathing. In the history of Rome, we find many members of the Julio-Claudian family affected with probable atopic respiratory disorders: Caesar Augustus suffered from bronchoconstriction, seasonal rhinitis as well as a highly pruritic skin disease. Claudius suffered from rhinoconjunctivitis and Britannicus was allergic to horse dander [529]. Maimonides (1136–1204) warned that to neglect treatment of asthma could prove fatal, whereas until the 19th century, European scholars defined it as “nervous asthma,” a term that was given to mean a defect of conductivity of the ninth pair of cranial nerves.

Ketotifen alone or as additional medication for long-term control of asthma and wheeze in children

BACKGROUND

Ketotifen is an antihistamine which may be used to treat asthma. Since administering inhaled therapy to younger children can be difficult, an oral agent such as ketotifen offers potential advantages.

OBJECTIVES

The objective of this review is to determine, whether ketotifen alone or in combination with other co-interventions results in better control of asthma in children with asthma and/or wheezing and examine its safety profile.

SEARCH STRATEGY

We searched the Cochrane Airways Group register of trials (based on MEDLINE, EMBASE, CINAHL and handsearched respiratory journals) and reference lists of articles. The latest search was carried out in October 2002.

SELECTION CRITERIA

Clinical studies had to be randomised-controlled and double-blinded, comparing oral ketotifen with placebo in children with asthma and/or wheeze for at least eight weeks at a dose not less than one mg daily.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed selection of trials, quality assessment and data extraction; a third reviewer was included in the consensus process if necessary.

MAIN RESULTS

A total of 26 relevant studies involving 1826 participants were included in this review. Children's age ranged from 4 months to 18 years and ketotifen was given between 10 and 32 weeks. The proportion of children able to reduce or stop their bronchodilator use within 12 to 16 weeks of treatment was significantly higher in the ketotifen group (relative risk 2.39, 95% CI 1.64 to 3.48) based on four trials; this result was statistically significant in a subgroup of two trials with well described and adequate method of blinding. Statistically significant beneficial effects of ketotifen were also observed in the following secondary outcomes: efficacy evaluated by physician (10 trials) and parents/patients (7 trials), asthma symptom score (4 trials), asthma exacerbations (2 trials), and reduction in use of oral steroids (4 trials). However, sub-group analyses of trials with well described and adequate method of blinding was only significant for the outcome asthma symptom score and non-significant for the remaining secondary outcomes. Reported side effects were more frequent in the ketotifen group (sedation: 21%, weight gain: 27%) than in the placebo group (sedation: 12%, weight gain: 17%).

REVIEWER'S CONCLUSIONS

Evidence from randomised controlled trials indicates that ketotifen alone or in combination with other co-interventions improves control of asthma and wheezing in children with mild and moderate asthma. However due to the high proportion of children with atopy in some trials the results cannot necessarily be generalised to all asthmatic children. The benefit is obtained at the cost of minor side effects, namely sedation and weight gain. The validity of this conclusion is limited by the low reported, methodological quality of included trials.

Impact of rhinitis on airway inflammation: biological and therapeutic implications

There is increasing evidence for a close link between the upper and the lower respiratory tracts and the fact that rhinitis has an important impact on asthma. Several clinical and experimental observations suggest a similar immunopathology between the upper and lower airways in allergic subjects. The common inflammatory process that develops in the respiratory tract explains some of the complex interactions among different clinical diseases such as rhinitis, sinusitis, asthma, bronchial hyperresponsiveness and viral infections. There are also non-inflammatory mechanisms that may contribute to the link between rhinitis and asthma. Moreover, the outcomes of various pharmacological treatments of rhinitis have recently provided further support for the hypothesis of the united airways. We discuss some of the recent observations on the nose-lung interaction and some of the novel therapeutic approaches used to treat rhinitis and asthma that arise from this.

Fever of unknown origin in a 10-year-old boy with allergic rhinitis and asthma

We believe this case represents a clear example of drug fever, and it appears to be the first report to implicate ketotifen as the responsible agent, confirmed with double rechallenge. The recognition of drug fever is clinically important. Failure to recognize the etiologic relationship between the drug and fever has unnecessary consequences, including extra testing, empiric therapy, and longer hospital stays. We suggest that ketotifen should be considered as a possible cause of fever in allergic patients receiving this drug.

Ketotifen for asthma in children aged 5 to 15 years: a randomized placebo-controlled trial

BACKGROUND

The prophylactic agent ketotifen has been studied in mild-to-moderate asthma. Various trials showed benefit from 10 to 12 weeks of therapy, but no trial in children with followup beyond 12 weeks of the drug is available.

OBJECTIVES

We studied the efficacy of ketotifen, 1 mg twice a day, orally as a prophylactic drug in children with asthma.

METHODS

The double-blind, placebo-controlled trial studied 120 asthmatic children of either sex between the ages of 5 to 15 years at a tertiary care hospital. After an observation period of 4 weeks, children were randomly assigned to receive either ketotifen, 1 mg twice a day, or placebo for 6 months. Antiasthma drugs were continued as required. Main outcome measures included average duration for regular antiasthma drugs, average symptom scores, symptom free days, peak expiratory flow rate, FEV1, and need for emergency room visits.

RESULTS

Of the 120 children enrolled, 13 could not complete the trial. Thus 58 children remained in the treatment group and 49 were in the placebo group. Both groups were comparable in their baseline characteristics. The average number of days that required antiasthma drugs were significantly less in the treatment group: salbutamol (27+/-4.7 versus 37+/-3.5 P < .05), theophylline (37+/-4.7 versus 51+/-4.8 P < .05), oral steroids (2+/-0.4 versus 5+/-1.6 P < .05), and inhalation steroids (18+/-2.7 versus 16+/-10.8 P < .05). The average symptom scores and symptom free days for cough, wheeze, and breathlessness also favored the ketotifen group. Emergency room visits were also significantly lower in the ketotifen group (20 versus 10 P < .05). Statistically significant improvement in all the above parameters were observed after 14 weeks of therapy. The mean PEFR, FEV1 and side effects of medications were comparable between the two groups.

CONCLUSIONS

Ketotifen, 1 mg twice a day, is an effective prophylaxis for asthma in children between 5 to 15 years. Significant clinical improvement is evident after 14 weeks of therapy.

[Antiallergy drugs and respiratory diseases in children]

Second generation antihistamines (anti H1) are effective for seasonal and perennial rhinoconjunctivitis curative or preventive treatment in children. They are better tolerated than first generation drugs. They probably do not act specifically against asthma itself, but are nevertheless useful for relief of nasal obstruction, which is an asthmogenic factor frequently linked with bronchial asthma. The therapeutic relevance of oral ketotifen and inhaled chromones (sodium cromoglycate, nedocromil sodium) is unequally considered among pediatricians. However, their efficacy has been clearly demonstrated as a ground treatment in mild-to-moderate asthmatic children. Chromones are also useful in preventing exercise-induced asthma. Because of their low cost and the lack of potential side effects, and according to the guidelines established in 1997 by the National Heart, Lung and Blood Institute, they should be prescribed at first sight in these indications.

Antihistamines in the treatment of asthma

Antihistamines were investigated for use in asthma shortly after discovery over fifty years ago. Earlier compounds proved ineffective because of side effects: this class of drugs was not thought useful for asthma, and were actually considered contraindicated. More recent drugs have greater potency, fewer side-effects, and no evidence of adverse effects in asthma. There are some studies showing second generation antihistamines, especially cetirizine, improve certain parameters of asthma.

Neural mechanisms and axon reflexes in asthma. Where are we?

For many years, asthma has been classified as a "neural" disease, with an imbalance between constrictor and dilator nerves being responsible for the symptomatology. Although, nowadays, asthma is recognized as an inflammatory disorder of the airways, neural mechanisms remain very important; axon reflexes, in particular, have received a lot of attention in recent years. In this commentary, an overview is given on the innervation of the airways and its relevance in asthma, and potential new insights in airways innervation are discussed. In a second part, the role of axon reflexes is highlighted. Although neuropeptides such as substance P and neurokinin A are present in human airways, where they produce many of the features characteristic of asthma, and although there is an elevation of their content in induced sputum from asthmatics, there is still no clear direct evidence for the existence of operational axon reflexes in human airways. Most of the research focused on this subject is performed in guinea pigs, where such an axon reflex clearly operates in the airways. In these animals, different receptors have been identified on C-fiber endings, which, upon stimulation, cause inhibition of neuropeptide release. Some of these receptors have also been identified on human airway nerves. Therefore, it has been suggested that modulation of axon reflexes could be of potential benefit in asthma treatment. Indeed, some drugs (e.g. sodium cromoglycate, nedocromil sodium, and ketotifen), which have been demonstrated to partially inhibit neuropeptide release in guinea pig airways, have anti-inflammatory effects on neuropeptide release in guinea pig airways, do not seem to have any anti-inflammatory effects in human asthma. Other drugs, however, such as beta2-mimetics, which have a much more pronounced inhibitory effect in asthma. In conclusion, although there is a lot of indirect evidence for the existence of axon reflex mechanisms in human airways, most of the data now available are derived from animal studies. The key question of whether axon reflexes are operational in human airways remains unanswered. Hopefully, the near future will bring a solution to this enigma with the introduction of very potent tachykinin antagonists for the treatment of human asthma.

Asthma and chronic obstructive lung disease: a pharmacologic approach

Changing concepts are emerging that should improve our ability to adequately treat asthma. This volume of Disease-a-Month reviews the triggers and the role of inflammation in asthma, and outlines the treatment of acute asthma as well as the chronic management of reversible obstructive airways disease. There is general agreement that sympathomimetics are the treatment of choice for acute severe asthma. The role of theophylline for acute symptoms has been downplayed, and the role of corticosteroids continues to be debated. However, most authorities agree that patients with severe asthma will benefit from the addition of corticosteroids to the program. For the chronic management of asthma, appreciation that inflammation is a perpetuating feature suggests that treatment should generally be directed toward the inflammation. Corticosteroid aerosols have taken on greater prominence and have been advocated as the first line of approach. New concepts regarding the role of allergy in the perpetuation of asthma and the role of immunotherapy in its amelioration also have emerged. Medications not previously thought to be beneficial are being actively investigated. They include gold, methotrexate, and even intravenous gamma globulin.

Ketotifen reduces sneezing but not histamine release following nasal challenge with antigen

We evaluated the effect of pre-treatment with 1 and 2 mg b.i.d. of ketotifen on the early response to nasal challenge in a double-blind cross-over trial. Weekly nasal challenges were performed in 10 allergic subjects after 1 hr and 1, 2, 3 and 4 weeks of ketotifen administration. The response to nasal challenge was monitored by counting the number of sneezes, the assessment of subjective symptoms, and by measuring the levels of histamine and TAME-esterase activity in recovered nasal lavages. The number of sneezes diminished significantly after a single dose of drug with both the 1 and 2 mg doses. Prolonged pre-treatment did not improve the results. The levels of histamine and TAME-esterase activity in recovered nasal lavages were not changed significantly by either pre-treatment at either dose. Although the number of subjects was small, our data suggest that ketotifen diminishes allergic symptomatology by its antihistaminic properties rather than by inhibiting histamine release from mast cells. As we did not look into the effects of ketotifen on other products generated by mast cells (prostanoids, leukotrienes and tryptase), we cannot fully rule out an effect on mast cells.

Investigation of the effect of ketotifen on alcohol-induced asthma: a case study

A male patient with bronchial asthma suffered severe exacerbation of symptoms after drinking alcohol and this was not prevented by treatment with bronchodilators. After taking 1 mg ketotifen twice daily for nasal obstruction, within 1 month there was no longer any exacerbation of symptoms by alcohol. Blood samples were taken and peripheral eosinophils were purified and incubated with beer antigen. Using a chemiluminescence method, it was shown that pretreatment with ketotifen dose dependently inhibited the generation of the highly reactive oxygen metabolite superoxide (O2-) by the eosinophils. It is proposed that ketotifen prevented the alcohol-exacerbated asthma attacks by inhibiting the release of tissue-damaging superoxide from eosinophils.

Ketotifen. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in asthma and allergic disorders

Ketotifen is an orally active prophylactic agent for the management of bronchial asthma and allergic disorders. Accumulated evidence indicates that after 6 to 12 weeks of administration, ketotifen significantly reduces respiratory symptoms and the need for concomitant antiasthmatic drugs in about 70% and 50%, respectively, of patients with mild to moderate bronchial asthma. However, absolute improvement in lung function is generally slight. Ketotifen also has pronounced antihistaminic and antianaphylactic properties which result in moderate to marked symptom improvement in the majority of patients with atopic dermatitis, seasonal or perennial rhinitis, allergic conjunctivitis, chronic or acute urticaria or food allergy. Comparative trials with established agents--notably sodium cromoglycate (cromolyn sodium) in asthma and histamine H1-antagonists in allergic disorders--indicate that ketotifen has comparable clinical utility. Unlike inhaled sodium cromoglycate, ketotifen ameliorates the symptoms of asthma, rhinitis and dermatitis when present together in atopic patients. Patient acceptance of ketotifen is good, although sedation can be troublesome in older children and adults for the initial 2 weeks of treatment. Weight gain is another notable effect in a small percentage of patients. Thus, ketotifen appears to be a useful agent for the management of allergic disorders and bronchial asthma, particularly in patients for whom oral therapy is preferred. Although a lengthy run-in period is needed in the treatment of asthma, in those patients who respond, continued reduction in the frequency and severity of symptoms and in the use of additional antiasthmatic drugs can be anticipated.