Dasselta

Dasselta is indicated in adults, adolescents and children over the age of 1 year for the relief of symptoms associated with:

- allergic rhinitis

- urticaria.

Posology

Adults and adolescents 12 years of age and over.

The recommended dose of Dasselta oral solution is 10ml (5mg) oral solution once a day.

Paediatric Population

The prescriber should be aware that most cases of rhinitis below 2 years of age are of infectious origin and there are no data supporting the treatment of infectious rhinitis with Dasselta oral solution.

Children 1 through 5 years of age: 2.5 ml (1.25 mg) Dasselta oral solution once a day.

Children 6 through 11 years of age: 5 ml (2.5 mg) Dasselta oral solution once a day.

The safety and efficacy of Dasselta 0.5mg/ml oral solution in children below the age of 1 year have not been established. No data are available.

There is limited clinical trial efficacy experience with the use of Dasselta in children 1 through 11 years of age and adolescents 12 through 17 years of age.

Intermittent allergic rhinitis (presence of symptoms for less than 4 days per week or for less than 4 weeks) should be managed in accordance with the evaluation of patient's disease history and the treatment could be discontinued after symptoms are resolved and reinitiated upon their reappearance.

In persistent allergic rhinitis (presence of symptoms for 4 days or more per week and for more than 4 weeks), continued treatment may be proposed to the patients during the allergen exposure periods.

Method of Administration

Oral use.

The dose can be taken with or without food.

Paediatric population

In children below 2 years of age, the diagnosis of allergic rhinitis is particularly difficult to distinguish from other forms of rhinitis. The absence of upper respiratory tract infection or structural abnormalities, as well as patient history, physical examinations, and appropriate laboratory and skin tests should be considered.

Approximately 6 % of adults and children 2- to 11-year old are phenotypic poor metabolisers of Dasselta and exhibit a higher exposure. The safety of Dasselta in children 2- to 11-years of age who are poor metabolisers is the same as in children who are normal metabolisers. The effects of Dasselta in poor metabolisers < 2 years of age have not been studied.

In the case of severe renal insufficiency, Dasselta oral solution should be used with caution.

This medicinal product contains sorbitol. Patients with rare hereditary problems of fructose intolerance should not take this medicine.

Dasselta oral solution has no or negligible influence on the ability to drive and use machines based on clinical trials. Patients should be informed that most people do not experience drowsiness. Nevertheless, as there is individual variation in response to all medicinal products, it is recommended that patients are advised not to engage in activities requiring mental alertness, such as driving a car or using machines, until they have established their own response to the medicinal product.

Summary of the safety profile

Paediatric population

In clinical trials in a paediatric population, the Dasselta syrup formulation was administered to a total of 246 children aged 6 months through 11 years. The overall incidence of adverse events in children 2 through 11 years of age was similar for the Dasselta and the placebo groups. In infants and toddlers aged 6 to 23 months, the most frequent adverse events reported in excess of placebo were diarrhoea (3.7 %), fever (2.3 %) and insomnia (2.3 %). In an additional study, no adverse events were seen in subjects between 6 and 11 years of age following a single 2.5 mg dose of Dasselta oral solution.

In a clinical trial with 578 adolescent patients, 12 through 17 years of age, the most common adverse event was headache, this occurred in 5.9% of patients treated with Dasselta and 6.9% of patients receiving placebo.

Adults and adolescents

At the recommended dose, in clinical trials involving adults and adolescents in a range of indications including allergic rhinitis and chronic idiopathic urticaria, undesirable effects with Dasselta were reported in 3 % of patients in excess of those treated with placebo. The most frequent of adverse events reported in excess of placebo were fatigue (1.2 %), dry mouth (0.8 %) and headache (0.6 %).

Tabulated list of adverse reactions

The frequency of the clinical trial adverse reactions reported in excess of placebo and other undesirable effects reported during the post-marketing period are listed in the following table.

Frequencies are defined as very common (>1/10), common (>1/100 to <1/10), uncommon (>1/1,000 to <1/100), rare (>1/10,000 to <1/1,000), very rare (<1/10,000) and not known (cannot be estimated from the available data).

Paediatric population

Other undesirable effects reported during the post-marketing period in paediatric patients with an unknown frequency included QT prolongation, arrhythmia and bradycardia.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorization of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard

The adverse event profile associated with overdosage, as seen during post-marketing use, is similar to that seen with therapeutic doses, but the magnitude of the effects can be higher.

Treatment

In the event of overdose, consider standard measures to remove unabsorbed active substance. Symptomatic and supportive treatment is recommended.

Dasselta is not eliminated by haemodialysis; it is not known if it is eliminated by peritoneal dialysis.

Symptoms

Based on a multiple dose clinical trial in adults and adolescents, in which up to 45 mg of Dasselta was administered (nine times the clinical dose), no clinically relevant effects were observed.

Paediatric population

The adverse event profile associated with overdosage, as seen during post-marketing use, is similar to that seen with therapeutic doses, but the magnitude of the effects can be higher.

Pharmacotherapeutic group: antihistamines - H₁ antagonist

ATC code: R06A X27

Mechanism of action

Dasselta is a non-sedating, long-acting histamine antagonist with selective peripheral H₁-receptor antagonist activity. After oral administration, Dasselta selectively blocks peripheral histamine H₁-receptors because the substance is excluded from entry to the central nervous system.

Dasselta has demonstrated antiallergic properties from in vitro studies. These include inhibiting the release of proinflammatory cytokines such as IL-4, IL-6, IL-8, and IL-13 from human mast cells/basophils, as well as inhibition of the expression of the adhesion molecule P-selectin on endothelial cells. The clinical relevance of these observations remains to be confirmed.

Clinical efficacy and safety

Paediatric population

Efficacy of Dasselta oral solution has not been investigated in separate paediatric trials. However, the safety of Dasselta syrup, which contains the same concentration of Dasselta as Dasselta oral solution, was demonstrated in three paediatric trials. Children, 1-11 years of age, who were candidates for antihistamine therapy received a daily Dasselta dose of 1.25 mg (1 through 5 years of age) or 2.5 mg (6 through 11 years of age). Treatment was well tolerated as documented by clinical laboratory tests, vital signs, and ECG interval data, including QTc. When given at the recommended doses, the plasma concentrations of Dasselta were comparable in the paediatric and adult populations. Thus, since the course of allergic rhinitis/chronic idiopathic urticaria and the profile of Dasselta are similar in adults and paediatric patients, Dasselta efficacy data in adults can be extrapolated to the paediatric population. Efficacy of Dasselta syrup has not been investigated in paediatric trials in children less than 12 years of age.

Adults and adolescents

In a multiple dose clinical trial, in adults and adolescents, in which up to 20 mg of Dasselta was administered daily for 14 days, no statistically or clinically relevant cardiovascular effect was observed. In a clinical pharmacology trial, in adults and adolescents, in which Dasselta was administered to adults at a dose of 45 mg daily (nine times the clinical dose) for ten days, no prolongation of QTc interval was seen.

Dasselta does not readily penetrate the central nervous system. In controlled clinical trials, at the recommended dose of 5 mg daily for adults and adolescents, there was no excess incidence of somnolence as compared to placebo. Dasselta tablets given at a single daily dose of 7.5 mg to adults and adolescents did not affect psychomotor performance in clinical trials. In a single dose study performed in adults, Dasselta 5 mg did not affect standard measures of flight performance including exacerbation of subjective sleepiness or tasks related to flying.

In clinical pharmacology trials in adults, co-administration with alcohol did not increase the alcohol-induced impairment in performance or increase in sleepiness. No significant differences were found in the psychomotor test results between Dasselta and placebo groups, whether administered alone or with alcohol.

No clinically relevant changes in Dasselta plasma concentrations were observed in multiple-dose ketoconazole and erythromycin interaction trials.

In adult and adolescent patients with allergic rhinitis, Dasselta tablets were effective in relieving symptoms such as sneezing, nasal discharge and itching, as well as ocular itching, tearing and redness, and itching of palate. Dasselta effectively controlled symptoms for 24 hours. The efficacy of Dasselta tablets has not been clearly demonstrated in trials with adolescent patients 12 through 17 years of age.

In addition to the established classifications of seasonal and perennial, allergic rhinitis can alternatively be classified as intermittent allergic rhinitis and persistent allergic rhinitis according to the duration of symptoms. Intermittent allergic rhinitis is defined as the presence of symptoms for less than 4 days per week or for less than 4 weeks. Persistent allergic rhinitis is defined as the presence of symptoms for 4 days or more per week and for more than 4 weeks.

Dasselta tablets were effective in alleviating the burden of seasonal allergic rhinitis as shown by the total score of the rhino-conjunctivitis quality of life questionnaire. The greatest amelioration was seen in the domains of practical problems and daily activities limited by symptoms.

Chronic idiopathic urticaria was studied as a clinical model for urticarial conditions, since the underlying pathophysiology is similar, regardless of etiology, and because chronic patients can be more easily recruited prospectively. Since histamine release is a causal factor in all urticarial diseases, Dasselta is expected to be effective in providing symptomatic relief for other urticarial conditions, in addition to chronic idiopathic urticaria, as advised in clinical guidelines.

In two placebo-controlled six week trials in patients with chronic idiopathic urticaria, Dasselta was effective in relieving pruritus and decreasing the size and number of hives by the end of the first dosing interval. In each trial, the effects were sustained over the 24 hour dosing interval. As with other antihistamine trials in chronic idiopathic urticaria, the minority of patients who were identified as non-responsive to antihistamines was excluded. An improvement in pruritus of more than 50 % was observed in 55 % of patients treated with Dasselta compared with 19 % of patients treated with placebo. Treatment with Dasselta also significantly reduced interference with sleep and daytime function, as measured by a four-point scale used to assess these variables.

Absorption

Dasselta plasma concentrations can be detected within 30 minutes of Dasselta administration in adults and adolescents. Dasselta is well absorbed with maximum concentration achieved after approximately 3 hours; the terminal phase half-life is approximately 27 hours. The degree of accumulation of Dasselta was consistent with its half-life (approximately 27 hours) and a once daily dosing frequency. The bioavailability of Dasselta was dose proportional over the range of 5 mg to 20 mg.

In a series of pharmacokinetic and clinical trials, 6 % of the subjects reached a higher concentration of Dasselta. The prevalence of this poor metaboliser phenotype was comparable for adult (6 %) and paediatric subjects 2- to 11-year old (6 %), and greater among Blacks (18 % adult, 16 % paediatric) than Caucasians (2 % adult, 3 % paediatric) in both populations.

In a multiple-dose pharmacokinetic study conducted with the tablet formulation in healthy adult subjects, four subjects were found to be poor metabolisers of Dasselta. These subjects had a C_max concentration about 3-fold higher at approximately 7 hours with a terminal phase half-life of approximately 89 hours.

Similar pharmacokinetic parameters were observed in a multiple-dose pharmacokinetic study conducted with the syrup formulation in paediatric poor metaboliser subjects 2- to 11-year old diagnosed with allergic rhinitis. The exposure (AUC) to Dasselta was about 6-fold higher and the Cmax was about 3 to 4 fold higher at 3-6 hours with a terminal half-life of approximately 120 hours. Exposure was the same in adult and paediatric poor metabolisers when treated with age-appropriate doses. The overall safety profile of these subjects was not different from that of the general population. The effects of Dasselta in poor metabolizers < 2 years of age have not been studied.

In separate single dose studies, at the recommended doses, paediatric patients had comparable AUC and C_max values of Dasselta to those in adults who received a 5 mg dose of Dasselta syrup.

Distribution

Dasselta is moderately bound (83 % - 87 %) to plasma proteins. There is no evidence of clinically relevant active substance accumulation following once daily adult and adolescent dosing of Dasselta (5 mg to 20 mg) for 14 days.

In a single dose, crossover study of Dasselta, the tablet and the syrup formulations were found to be bioequivalent. As Dasselta oral solution contains the same concentration of Dasselta, no bioequivalence study was required and it is expected to be equivalent to the syrup and tablet.

Biotransformation

The enzyme responsible for the metabolism of Dasselta has not been identified yet, and therefore, some interactions with other medicinal products cannot be fully excluded. Dasselta does not inhibit CYP3A4 in vivo, and in vitro studies have shown that the medicinal product does not inhibit CYP2D6 and is neither a substrate nor an inhibitor of P-glycoprotein.

Elimination

In a single dose trial using a 7.5 mg dose of Dasselta, there was no effect of food (high-fat, high caloric breakfast) on the disposition of Dasselta. In another study, grapefruit juice had no effect on the disposition of Dasselta.

Renally impaired patients

The pharmacokinetics of Dasselta in patients with chronic renal insufficiency (CRI) was compared with that of healthy subjects in one-single-dose study and one multiple dose study. In the single-dose study, the exposure to Dasselta was approximately 2 and 2.5-fold greater in subjects with mild to moderate and severe CRI, respectively, than in healthy subjects. In the multiple-dose study, steady state was reached after Day 11, and compared to healthy subjects the exposure to Dasselta was ~1.5-fold greater in subjects with mild to moderate CRI and ~2.5-fold greater in subjects with severe CRI. In both studies, changes in exposure (AUC and C_max) of Dasselta and 3-hydroxyDasselta were not clinically relevant.

Dasselta is the primary active metabolite of loratadine. Non-clinical studies conducted with Dasselta and loratadine demonstrated that there are no qualitative or quantitative differences in the toxicity profile of Dasselta and loratadine at comparable levels of exposure to Dasselta.

Non-clinical data with Dasselta reveal no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, toxicity to reproduction and development. The lack of carcinogenic potential was demonstrated in studies conducted with Dasselta and loratadine.

Not applicable

Any unused medicinal product or waste material should be disposed of in accordance with local requirements.