Relevance of pharmacokinetics and pharmacodynamics of inhaled corticosteroids to asthma.

The pharmacokinetic and pharmacodynamic effects of inhaled corticosteroids (ICS) have shaped the efficacy and safety of these agents in the treatment of asthma. Important pharmacokinetic and pharmacodynamic characteristics that can enhance the efficacy of ICS include small particle size, high glucocorticoid-receptor-binding affinity, long pulmonary residence time and lipid conjugation. These characteristics can increase or prolong the anti-inflammatory effects of an ICS. Important pharmacokinetic characteristics that can enhance the safety of ICS include on-site activation in the lung, low oropharyngeal exposure, negligible oral bioavailability, high protein-binding and rapid systemic clearance. The degree of oropharyngeal exposure is relevant to local side-effects, such as oropharyngeal candidiasis, dysphonia and coughing. Pharmacokinetic properties that influence the degree of systemic exposure are relevant to the pharmacodynamic effect of ICS-induced hypothalamic-pituitary-adrenal axis suppression and cortisol suppression, an indicator of potential long-term systemic side-effects, such as reduced growth velocity and bone density, fractures, and skin bruising and thinning. Therefore, significant differences in the pharmacokinetic and pharmacodynamic characteristics of the currently available inhaled corticosteroids warrant careful consideration when used in clinical practice as they may result in differences in efficacy and local and systemic safety profiles.

Comparative efficacy of once-daily ciclesonide and budesonide in the treatment of persistent asthma.

BACKGROUND: The aim of this study was to compare the efficacy and safety of once-daily ciclesonide, a new-generation, on-site-activated, inhaled corticosteroid, with once-daily budesonide in persistent asthma. METHODS: Eligible patients requiring budesonide or equivalent 320-640 microg (ex-mouthpiece, equivalent to 400-800 microg; Turbohalertrade mark) daily entered a 2-week baseline, and then a 2- to 4-week pretreatment period (budesonide 1280 microg/day; ex-mouthpiece, equivalent to 1600 microg/day). Patients with an increase in forced expiratory volume in 1s (FEV1) of 7% or 0.15 L were randomised to ciclesonide 320 microg (ex-actuator, equivalent to 400 microg ex-valve) via a hydrofluoroalkane-metered dose inhaler (HFA-MDI) without a spacer or budesonide 320 microg once daily in the morning for 12 weeks. Change in FEV1 was the primary endpoint. RESULTS: In all, 359 patients were randomised. The FEV1 and forced vital capacity (FVC) decreased by 0.18 and 0.12L, respectively, in the ciclesonide group, and by 0.23 and 0.21L in the budesonide group. For FEV1, ciclesonide was noninferior and numerically superior to budesonide. For FVC, ciclesonide was statistically superior to budesonide (P=0.010). Asthma symptom scores were comparable; the median percentage of symptom-free days was significantly higher for ciclesonide (43.6%) versus budesonide (25.8%) (P=0.017). Rescue medication use decreased significantly only for ciclesonide patients (P=0.009). Frequency of adverse events was low in both groups. CONCLUSION: Ciclesonide 320 microg once daily by HFA-MDI without a spacer was at least as effective as budesonide 320 microg once daily in persistent asthma.

Once-daily ciclesonide 80 or 320 microg for 12 weeks is safe and effective in patients with persistent asthma.

The efficacy and safety of ciclesonide was assessed in this randomized, placebo-controlled study in patients with persistent asthma (randomized n=360) maintained on low to moderate doses of inhaled corticosteroids. Patients were randomized to receive ciclesonide 80 or 320 microg (ex-actuator doses, equivalent to 100 and 400 microg ex-valve, respectively) or placebo once daily in the morning via metered-dose inhaler for 12 weeks. Morning peak expiratory flow was maintained throughout the treatment period in patients treated with ciclesonide and decreased significantly in patients treated with placebo (P=0.0003). Ciclesonide (80 and 320 microg) significantly increased forced expiratory volume in 1s from baseline (0.13 and 0.19 L increases, respectively; P<0.01); improvements were superior versus placebo (P=0.0044 for 80 microg ciclesonide; P<0.0001 for 320 microg ciclesonide). The probability of losing efficacy decreased in a dose-dependent manner (55% for placebo, 38% for ciclesonide 80 microg, 23% for ciclesonide 320 microg). Asthma symptom scores and rescue medication use were unchanged with ciclesonide and significantly worsened with placebo. The incidence of adverse events was comparable in all treatment groups and no cortisol suppression was observed. Therefore, ciclesonide 80 and 320 microg administered once daily was a safe and effective maintenance treatment for patients with persistent asthma.

Lack of pharmacokinetic drug-drug interaction between ciclesonide and erythromycin.

OBJECTIVE: To investigate whether systemic exposure to desisobutyrylciclesonide (des-CIC) (the pharmacologically active metabolite of ciclesonide) and erythromycin are affected by combined administration of ciclesonide and erythromycin. METHODS: 18 healthy subjects were enrolled in a Phase 1, open-label, randomized, three-period crossover study. Each subject received ciclesonide (640 microg ex-actuator, equivalent to 800 microg ex-valve, via hydrofluoroalkane metered-dose inhaler) and erythromycin (500 mg PO), separately and in combination, in random order. Blood samples were collected at timed intervals to determine serum concentrations of erythromycin, des-CIC, and ciclesonide using HPLC-MS detection. Adverse events were recorded throughout the study. RESULTS: Combined administration of ciclesonide and erythromycin did not alter the pharmacokinetics (PK) of either drug. The serum concentration vs. time profiles of erythromycin, des-CIC, and ciclesonide were similar when ciclesonide and erythromycin were administered separately or together. In addition, the PK characteristics of erythromycin and des-CIC were equivalent following single or co-administration. Point estimates (90% confidence intervals (CI)) for erythromycin were as follows: AUC0-inf, 0.96 (0.79, 1.18); Cmax, 1.00 (0.84, 1.20); and t1/2, 0.96 (0.83, 1.12). The following point estimates (90% CI) were obtained for des-CIC: AUC0-inf, 1.16 (1.03, 1.30); Cmax, 1.06 (0.98, 1.15); and t1/2, 1.04 (0.96, 1.13). Lack of ciclesonide/erythromycin interaction was demonstrated as the 90% CI of AUC0-inf, Cmax, and t1/2 of both compounds were entirely within the stipulated equivalence range of 0.67 - 1.50. No study drug-related adverse events occurred during this study. CONCLUSIONS: Combined administration of ciclesonide and erythromycin did not alter the PK properties of either drug. Both drugs were safe and well-tolerated. Therefore, systemic exposure to ciclesonide or erythromycin is not increased in patients receiving concomitant therapy.