Pharmacokinetic comparison of inhaled fixed combination vs. the free combination of beclomethasone and formoterol pMDIs in asthmatic children

Impact of Single Combination Inhaler versus Multiple Inhalers to Deliver the Same Medications for Patients with Asthma or COPD: A Systematic Literature Review

With increasing choice of medications and devices for asthma and chronic obstructive pulmonary disease (COPD) treatment, comparative evidence may inform treatment decisions. This systematic literature review assessed clinical and economic evidence for using a single combination inhaler versus multiple inhalers to deliver the same medication for patients with asthma or COPD. In 2016, Embase, PubMed and the Cochrane library were searched for publications reporting studies in asthma or COPD comparing a single-inhaler combination medicine with multiple inhalers delivering the same medication. Publications included English-language articles published since 1996 and congress abstracts since 2013. Clinical, economic and adherence endpoints were assessed. Of 2031 abstracts screened, 18 randomized controlled trials (RCTs) in asthma and four in COPD, nine retrospective and three prospective observational studies in asthma, and four observational studies in COPD were identified. Of these, five retrospective and one prospective study in asthma, and two retrospective studies in COPD reported greater adherence with a single inhaler than multiple inhalers. Nine observational studies reported significantly (n=7) or numerically (n=2) higher rates of adherence with single- versus multiple-inhaler therapy. Economic analyses from retrospective and prospective studies showed that use of single-inhaler therapies was associated with reduced healthcare resource use (n=6) and was cost-effective (n=5) compared with multiple-inhaler therapies. Findings in 18 asthma RCTs and one prospective study reporting lung function, and six RCTs reporting exacerbation rates, showed no significant differences between a single inhaler and multiple inhalers. This was in contrast to several observational studies reporting reductions in healthcare resource use or exacerbation events with single-inhaler treatment, compared with multiple inhalers. Retrospective and prospective studies showed that single-inhaler use was associated with decreased healthcare resource utilization and improved cost-effectiveness compared with multiple inhalers. Lung function and exacerbation rates were mostly comparable in the RCTs, possibly due to study design.

Hair cortisol and inhaled corticosteroid use in asthmatic children

BACKGROUND

Adrenal suppression is a side effect of long-term use of inhaled corticosteroids (ICS). Hair cortisol concentration (HCC) measurement is a noninvasive tool for measuring adrenal function that may be useful for asthmatic patients who are on long-term ICS treatment. The aim of this study was to compare HCC between children with and without asthma and to explore the association between HCC and ICS dose in asthmatic children.

METHODS

A cross-sectional observational study in subjects with or without asthma (n = 72 and 226, respectively, age 6-21 years). Hair samples were obtained from the posterior vertex for each subject and data on medication use were collected using questionnaires. HCC was analyzed by liquid chromatography-mass spectrometry in the most proximal 3 cm of hair.

RESULTS

Median HCC was significantly lower in subjects with asthma than in subjects without asthma: 1.83 pg/mg and 2.39 pg/mg, respectively (P value after adjustment for age, sex, and body mass index: .036). Median HCC was 1.98 pg/mg in asthmatics using no ICS, 1.84 pg/mg in those using a low dose, 1.75 pg/mg in those on a medium dose, and 1.46 in those using a high ICS dose (P = .54).

CONCLUSION

We observed a significantly lower HCC in asthmatics than in healthy controls and a nonsignificant trend of lower HCC with increasing ICS dose. Whether HCC measurement may be used to detect individuals at risk for hypocortisolism and may be useful to monitor adrenal function in asthmatic children using ICS needs to be further investigated.

Biological Obstacles for Identifying In Vitro-In Vivo Correlations of Orally Inhaled Formulations

Oral inhalation of drugs is the classic therapy of obstructive lung diseases. In contrast to the oral route, the link between in vitro and in vivo findings is less well defined and predictive models and parameters for in vitro-in vivo correlations are missing. Frequently used in vitro models and problems in obtaining in vivo values to establish such models and to identify the action of formulations in vivo are discussed. It may be concluded that major obstacles to link in vitro parameters on in vivo action include lack of treatment adherence and incorrect use of inhalers by patients, variation in inhaler performance, changes by humidity, uncertainties about lung deposition, and difficulties to measure drug levels in epithelial lining fluid and tissue. Physiologically more relevant in vitro models, improvement in inhaler performance, and better techniques for in vivo measurements may help to better understand importance and interactions between individual in vitro parameters in pulmonary delivery.

Pharmacokinetics and pharmacodynamics of an extrafine fixed pMDI combination of beclometasone dipropionate/formoterol fumarate in adolescent asthma

AIM

The aim was to investigate the pharmacokinetics and pharmacodynamics of an extrafine pressurized metered-dose inhaler (pMDI) fixed combination of beclometasone dipropionate (BDP)/formoterol fumarate (FF) in adolescent and adult asthma.

METHODS

This was a three-way crossover study, on 30 asthmatic adolescents receiving BDP/FF pMDI with or without a valved holding chamber (VHC) or a free licenced combination of BDP pMDI and FF pMDI plus a parallel arm of 30 asthmatic adults receiving BDP/FF pMDI. All patients received a single dose of BDP and FF of 400 µg and 24 µg, for each treatment, respectively. Assessments were performed over 8 hours.

RESULTS

In adolescents, the 90% confidence intervals (CIs) for the systemic exposure (AUC(0,t)) geometric mean ratio of the fixed combination with or without VHC vs. the free combination were within the bioequivalence range 0.80-1.25, both for beclometasone-17-monopropionate (B17MP, the active metabolite of BDP) and formoterol. Pharmacodynamic variables for plasma potassium and glucose, pulse rate and pulmonary function in adolescents were equivalent between treatments, 95% CI within 0.9, 1.09. The upper level of 90% CIs for AUC(0,t) geometric mean ratio adolescents : adults of B17MP and formoterol after treatment with BDP/FF pMDI was lower than 1.25, 90% CI 0.78, 1.04 and 0.86, 1.17, respectively.

CONCLUSIONS

In adolescents the pharmacodynamics and the overall systemic exposure to the active ingredients of an extrafine fixed combination of BDP/FF pMDI with or without a VHC was equivalent to that of a free licenced combination of pMDIs of established safety and efficacy profiles. The systemic exposure in adolescents was not higher than in adults. These results support the indication for use of inhaled corticosteroid/long acting β2 -adrenoceptor agonist pMDIs in adolescents at the same dosage as in adults.

Systemic exposure to inhaled beclometasone/formoterol DPI is age and body size dependent

AIM

Prescription of inhaled corticosteroids to children with asthma is recommended at half the nominal dose of adults in order to reduce the risk of systemic side effects. However, there is a lack of pharmacokinetic trials supporting such dose reduction regimens. Therefore, we aimed to compare the systemic exposure to the active ingredients of a fixed dose combination of beclometasone-dipropionate (BDP) and formoterol after dry powder inhaler (DPI) administration in children, adolescents and adults.

METHODS

The pharmacokinetic profiles of formoterol and beclometasone-17-monopropionate (B17MP; active metabolite of BDP) were evaluated over 8 h from two independent studies comprising children (6-11yrs, n = 27), adolescents (12-17 yrs, n = 28) and adults (≥18 yrs, n = 30) receiving a single, fixed dose of BDP/formoterol (children: 200 μg/24 μg, adolescents and adults: 400 μg/24 μg) via DPI.

RESULTS

The systemic exposure (AUC) for children versus adults was almost doubled for formoterol and similar for B17MP despite the halved BDP dose administered in children. In adolescents the AUC for formoterol and B17MP were approximately one third higher than in adults for both compounds. Upon normalization for the BDP/formoterol dose in the three populations the AUC and peak concentration (C(max)) correlated inversely with age and body surface area of the patients (r ≤ -0.53; p < 0.0001).

CONCLUSION

The systemic exposure to the active ingredients of BDP/formoterol administered as DPI correlates inversely with age and body size suggesting that dry powder dosage regimens should be adjusted for age and body size to avoid high systemic drug levels in children.

The systemic exposure to inhaled beclometasone/formoterol pMDI with valved holding chamber is independent of age and body size

BACKGROUND

Asthma guidelines recommend prescription of inhaled corticosteroids at a reduced dosage in children compared to older patients in order to minimize the systemic exposure and risk of unwanted side effects. In children, pressurized metered dose inhalers (pMDI) are recommended in combination with a valved holding chamber (VHC) to overcome the problem of coordinating inhalation with actuation. However, the influence of age and body size on the systemic exposure of drugs to be administered via a pMDI with VHC is still not fully elucidated. Therefore, we aimed to compare the systemic exposure to the active ingredients of a fixed combination of beclometasone-dipropionate/formoterol-fumarate administered via pMDI with VHC in children, adolescents and adults.

METHODS

The pharmacokinetics of formoterol and beclometasone-17-monopropionate (active metabolite of beclometasone-dipropionate) was evaluated over 8 h from three studies, each performed in a different age and body size group. Children (7-11 years, n = 20), adolescents (12-17 years, n = 29) and adults (≥18 years, n = 24) received a single dose of beclometasone/formoterol (children: 200 μg/24 μg, adolescents and adults: 400 μg/24 μg) via pMDI with AeroChamber Plus™.

RESULTS

The systemic exposure in children in comparison to adolescents was equivalent for formoterol while it was halved for beclometasone-17-monopropionate in accordance with the halved dose of beclometasone administered in children (90% CIs within 0.8-1.25 for formoterol and 0.4-0.625 for beclometasone-17-monopropionate). The systemic exposure to beclometasone-17-monopropionate and formoterol was equivalent between adolescents and adults.

CONCLUSIONS

The systemic exposure to the active ingredients of a fixed dose combination of beclometasone/formoterol administered via pMDI with AeroChamber Plus™ correlates with the nominal dose independently of patient age and body size. Thus, dose reduction in relation to age when using a pMDI with VHC may be unnecessary for reducing the systemic exposure in children.

Aerosol particle size does not predict pharmacokinetic determined lung dose in children

In vitro measures of aerosol particles size, such as the fine particle mass, play a pivotal role for approval of inhaled anti-asthmatic drugs. However, the validity as a measure of dose to the lungs in children lacks evidence. In this study we investigated for the first time the association between an in vivo estimate of lung dose of inhaled drug in children and the corresponding particle size segments assessed ex vivo. Lung dose of fluticasone propionate after inhalation from a dry powder inhaler (Diskus®) was studied in 23 children aged 4-7 and 12-15 years with mild asthma. Six-hour pharmacokinetics was assessed after single inhalation. The corresponding emitted mass of drug in segments of aerosol particle size was assessed ex vivo by replicating the inhalation flows recorded by transducers built into the Diskus® inhaler and re-playing them in a breathing simulator. There was no correlation between any inhaled particle size segment and lung dose assessed by pharmacokinetics and adjusted for age and body size. Measures of particles size segments were not related to lung dose in children. Until further evidence is provided it may be warranted to emphasize pharmacokinetic or pharmacodynamic assessments of drug delivery to the lung.