Study investigating pharmacokinetic interaction between theophylline and roflumilast in healthy adults.

OBJECTIVE: To investigate whether a pharmacokinetic drug-drug interaction exists between theophylline (THEO), a CYP1A2 substrate with a narrow therapeutic index, and the concomitant substrate roflumilast (ROF), a novel selective PDE4 inhibitor partially metabolized by CYP1A2. MATERIALS AND METHODS: In an open-label, 2-period, crossover study, Treatment A (oral ROF 500 µg q.d. on Days 6 - 10 in addition to oral THEO 375 mg b.i.d. on Days 1 - 10) and treatment B (oral ROF 500 µg q.d. on Days 1 - 5) were administered consecutively in random order to each of 24 healthy adult subjects. Both periods were separated by a wash-out phase of at least 10 days. Plasma samples for pharmacokinetic evaluation (AUC, Cmax, t1/2, tmax) including percent peak-trough fluctuation (%PTF) of THEO were taken. Point estimates and the 90% confidence interval of the geometric mean ratios were calculated for AUC and Cmax and descriptive statistics for other pharmacokinetic parameters. RESULTS: Concomitant administration of ROF did not alter pharmacokinetics of THEO. With coadministered THEO, only steady-state total exposure to ROF (AUC) was increased by 28% whereas other pharmacokinetic parameters (t1/2, Cmax, tmax) of ROF and of the active metabolite roflumilast-N-oxide (R-NO), its main contributor to the pharmacodynamic effects, remained unchanged. CONCLUSIONS: Neither ROF nor its main metabolite had any impact on the metabolism of the concomitant CYP1A2 substrate THEO in humans. Though co-administration of THEO resulted in a minor increase (28%) in total ROF exposure, no safety or tolerability concerns and no altered total PDE4 inhibition of both ROF and R-NO, were observed.

Influence of renal impairment on the pharmacokinetics of oral roflumilast: an open-label, parallel-group, single-center study.

OBJECTIVE: Roflumilast is a novel, orally active, selective phosphodiesterase 4 inhibitor recently approved in the European Union for the treatment of severe COPD. Roflumilast and its metabolites are mainly (70% of total radioactivity) eliminated via the kidneys as glucuronides. The potential impact of renal impairment on the pharmacokinetics of roflumilast and its active main metabolite roflumilast N-oxide were characterized. MATERIALS AND METHODS: Patients (n = 12) with severe renal impairment (creatinine clearance CL(CR) < 30 ml/ min/1.73 m²; otherwise healthy) and matched (sex, age, weight, and height) healthy control subjects (n = 12; CL(CR) > 80 ml/min/1.73 m²) were enrolled into an open-label, parallelgroup study. Single dose (500 µg, p.o.) pharmacokinetics and safety/tolerability of roflumilast and roflumilast N-oxide were compared between both groups. RESULTS: A minor decrease of exposure (area under the plasma concentration-time curve from time zero to infinity (AUC(0-∞)), maximum plasma concentration (C(max))) and a small increase in elimination half-life (t(1/2)) of roflumilast (-1%; -6%; +19%, respectively) and roflumilast N-oxide (-%; ND; +30%, respectively) were observed in renally impaired patients compared with healthy subjects. No relevant differences in safety and tolerability were observed between groups. CONCLUSIONS: The pharmacokinetic changes observed in patients with renal impairment are of small magnitude without clinical importance. A dose adjustment or a change in the administration interval of roflumilast is not necessary in patients with renal impairment.

Lack of pharmacokinetic and pharmacodynamic interactions of roflumilast with (R, S)-warfarin in healthy adult subjects.

UNLABELLED: Roflumilast is a novel, orally active, selective phosphodiesterase 4 inhibitor recently approved for the treatment of severe COPD. The pharmacological effect is mediated mainly by its active metabolite roflumilast N-oxide. OBJECTIVE: This doubleblind, 2-period cross-over study was conducted to investigate the potential effects of concomitant roflumilast on pharmacokinetics and pharmacodynamics of warfarin and vice versa. MATERIALS AND METHODS: A total of 24 healthy adults was enrolled into the study. Once-daily oral doses of roflumilast (500 µg) or placebo were given for 12 days, with subjects receiving both treatments one after the other; single oral doses of (R,S)-warfarin (25 mg) were administered on Day -14 and Day 8 of both periods. Warfarin enantiomer concentrations, prothrombin time (PT), and clotting factor activity (Factor VII, only) as well as concentrations of roflumilast and roflumilast N-oxide were measured in plasma. RESULTS: There was no clinically relevant pharmacokinetic or pharmacodynamic interaction between warfarin and roflumilast. Exposure over 120 h (area under the curve, AUC0-120) with "Test" (warfarin plus roflumilast) and "Reference" (warfarin plus placebo) treatment for Factor VII (geometric mean ratio 102.1% (90% confidence interval: 99.7 - 104.7%)) and excess AUC0-120 for PT (99.3% (92.3 - 106.9%)) were unchanged. CONCLUSIONS: Pharmacokinetic parameters including maximum plasma concentration (Cmax) and AUC0-∞ of (R)-, (S)-warfarin, roflumilast, and roflumilast N-oxide were unaffected by co-administration.

High absolute bioavailability of the new oral phosphodiesterase-4 inhibitor roflumilast.

OBJECTIVE: To establish basic intravenous (IV) pharmacokinetics of roflumilast (ROF) and its pharmacologically active metabolite roflumilast N-oxide (R-NO) and to determine the absolute bioavailability of ROF in humans. MATERIALS: In a randomized, open-label, 2-period, 2-sequence crossover study 12 healthy male subjects were randomized to receive ROF either orally (PO) 500 µg (immediate release tablets) or single IV (150 µg over 15 min). Plasma concentrations were determined. Dose-adjusted point estimates and 90% confidence intervals (CI) were calculated for the ratio of the AUC time curves using a multiplicative model and parametric analysis. RESULTS: After IV administration, clearance of ROF was 0.14 l/h/kg, volume of distribution (Vd area) 2.92 l/kg, and the terminal t1/2 was 14.8 h. After PO administration, ROF was rapidly absorbed; the absolute bioavailability was 79%. The AUC of the R-NO metabolite generally exceeded that of ROF. After IV and PO administration, the metabolic ratios were 7.4 and 12.4, respectively. Dose-adjusted analysis of the R-NO AUC values indicate a 21% higher R-NO formation seen with PO vs. IV, suggesting entire first-pass conversion of ROF is to the active R-NO. Formation/clearance processes of the R-NO appear to be slow with an observed tmax of 6.9 - 8.8 h, and corresponding to apparent t1/2 values of 22.7 h and 20.6 h, after IV and PO administration, respectively. CONCLUSION: ROF is rapidly absorbed after PO administration and exhibits high absolute bioavailability and low clearance pharmacokinetics. The total exposure of R-NO exceeds that of ROF by a factor of 12 after oral administration.

Evaluation of GERD symptoms during therapy. Part II. Psychometric evaluation and validation of the new questionnaire ReQuest in erosive GERD.

BACKGROUND/AIMS: Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest). This publication describes the psychometric evaluation and validation of ReQuest. METHODS: This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest. The psychometric analyses of ReQuest included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. RESULTS: Validation of ReQuest indicated very high internal consistency (Cronbach's alpha = 0.90) and test-retest reliability (intraclass correlation coefficient 0.94 (long-long) and 0.86 (short-short)). This was also the case for the two subscales ReQuest-GI and ReQuest-WSO with Cronbach's alpha coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of >0.8 at day 28. Construct validity was good. CONCLUSION: ReQuest is a highly reliable, valid and responsive self-assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.

Roflumilast, a once-daily oral phosphodiesterase 4 inhibitor, lacks relevant pharmacokinetic interactions with inhaled salbutamol when co-administered in healthy subjects.

OBJECTIVE: Roflumilast is an oral, once-daily phosphodiesterase 4 inhibitor under investigation for the treatment of chronic obstructive pulmonary disease and asthma. In clinical practice, the drug is likely to be co-administered with inhaled bronchodilating beta2-adrenoceptor agonists. Therefore, this study investigated the pharmacokinetic characteristics of roflumilast and its pharmacodynamically active metabolite roflumilast N-oxide when co-administered with orally inhaled salbutamol in healthy subjects. METHODS: In this open, randomized clinical study, 12 healthy male subjects received repeated doses of oral roflumilast 500 microg once daily, orally inhaled salbutamol 200 microg 3 times daily, and a combination of both drugs over 7 days according to a 3-period, changeover design with 14 days washout between treatments. RESULTS: Co-administration of roflumilast and salbutamol did not markedly change roflumilast or roflumilast N-oxide disposition. Point estimates (90% confidence intervals) of area under the curve from 0-24 h (AUC 0-24) and maximum plasma concentration in steady state (Cmax,ss) for roflumilast with salbutamol versus roflumilast alone were 1.05 (0.94, 1.17) and 0.97 (0.84, 1.10); the respective point estimates (90% confidence intervals) for AUC 0-24 and Cmax,ss of roflumilast N-oxide were 0.98 (0.91, 1.06) and 0.98 (0.92, 1.03). Roflumilast co-administration did not alter the pharmacokinetics of steady state salbutamol. The respective point estimates (90% confidence intervals) for AUC 0-6 and Cmax,ss of salbutamol with roflumilast versus salbutamol alone were 1.10 (0.99, 1.21), 1.08 (0.91, 1.28). The combination of both drugs was well tolerated. CONCLUSION: There were no relevant pharmacokinetic interactions between roflumilast and salbutamol at therapeutically effective doses.

Pharmacokinetic disposition of inhaled ciclesonide and its metabolite desisobutyryl-ciclesonide in healthy subjects and patients with asthma are similar.

OBJECTIVE: To evaluate whether the inflammatory process and bronchial constriction associated with asthma influence the pulmonary distribution and airway penetration of inhaled ciclesonide by investigating the pharmacokinetics of ciclesonide and its active metabolite, desisobutyryl-ciclesonide (des-CIC) in patients with asthma and matched healthy subjects. METHODS: 12 patients with asthma (8 males, 4 females) and 12 healthy subjects matched for age, sex, height, and weight received a single inhaled dose of 1,280 microg (ex-actuator, equivalent to 1,600 microg ex-valve) ciclesonide by metered-dose inhaler in a parallel-group study. Timed blood samples were collected for measurement of serum concentrations of des-CIC and ciclesonide by liquid chromatography with tandem mass spectrometry. RESULTS: There were no differences in the pharmacokinetics of des-CIC between healthy subjects and patients with asthma. Ratio analysis of the primary variable, the area under the concentration-time curve from time 0 to infinity (AUC(0 - inf)) showed equivalence for des-CIC in healthy subjects and patients with asthma, with a ratio of 1.003 (90% confidence interval between 0.815 and 1.234). The mean terminal half-life (t1/2) for des-CIC was also similar in patients with asthma (3.15 hours) and healthy subjects (3.33 hours). Furthermore, the pharmacokinetic parameter estimates for ciclesonide were comparable between the study groups. CONCLUSION: After administration of a single dose of ciclesonide, the pharmacokinetic parameter estimates for des-CIC were equivalent between patients with mild-to-moderate asthma and healthy subjects, suggesting that there is comparable lung deposition and activation of ciclesonide in the 2 populations.

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.

Evaluation of GERD symptoms during therapy. Part II. Psychometric evaluation and validation of the new questionnaire ReQuest in erosive GERD.

BACKGROUND/AIMS: Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest). This publication describes the psychometric evaluation and validation of ReQuest. METHODS: This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest. The psychometric analyses of ReQuest included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. RESULTS: Validation of ReQuest indicated very high internal consistency (Cronbach's alpha = 0.90) and test-retest reliability (intraclass correlation coefficient 0.94 (long-long) and 0.86 (short-short)). This was also the case for the two subscales ReQuest-GI and ReQuest-WSO with Cronbach's alpha coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of >0.8 at day 28. Construct validity was good. CONCLUSION: ReQuest is a highly reliable, valid and responsive self-assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.

Cure of Helicobacter pylori infection and healing of duodenal ulcer: comparison of pantoprazole-based one-week modified triple therapy versus two-week dual therapy. The International Pantoprazole HP Study Group.

OBJECTIVE: Eradication of Helicobacter pylori (H. pylori) is recommended as the first-line therapeutic concept for reliable long-term prevention of duodenal ulcer (DU) relapse. Current treatment regimens vary in efficacy, complexity, and compliance. To assess the efficacy of pantoprazole in H. pylori eradication in parallel groups of patients using two eradication regimens. METHODS: Patients, (18-85 yr old; intention-to-treat, n=286) with proven DU, positive rapid urease test (biopsy), and 13C-urea breath test (UBT) were included in a prospective, randomized, multicenter study. Modified triple therapy consisted of 40 mg pantoprazole b.i.d., 500 mg clarithromycin t.i.d., and 500 mg metronidazole t.i.d. for 7 days (PCM therapy); dual therapy consisted of 40 mg pantoprazole b.i.d. and 500 mg clarithromycin t.id. for 14 days (PC therapy). In both groups 40 mg pantoprazole o.d. was given until day 28 when healing of DU was evaluated endoscopically; H. pylori status was assessed by UBT on day 56. RESULTS: H. pylori eradication rate was 95% in PCM versus 60% in PC therapy groups (perprotocol population, p < 0.001), and 82% in PCM versus 50% in PC therapy in the intention-to-treat patient population (p < 0.001). The DU healing rate was 98% in the PCM and 95% in the PC therapy groups (per-protocol population). Both regimens were similarly well tolerated. Adverse events in both regimens included taste disturbance, diarrhea, and increased serum concentration of liver enzymes, at an incidence of < 10%. CONCLUSIONS: Compared to 2-wk PC therapy (pantoprazole and clarithromycin), the 1-wk PCM therapy (pantoprazole, clarithromycin, and metronidazole) is a significantly superior and highly promising strategy for eradication of H. pylori.

Efficacy and tolerability of pantoprazole 40 mg versus 80 mg in patients with reflux oesophagitis.

BACKGROUND: Pantoprazole is a substituted benzimidazole which is a potent inhibitor of gastric acid secretion by its action upon H+, K+-ATPase. METHODS: Pantoprazole 40 mg and 80 mg were compared in a randomized double-blind study in 192 out-patients with stage II or III (Savary-Miller classification) reflux oesophagitis. Patients received either pantoprazole 40 mg (n = 97) or pantoprazole 80 mg (n = 95), once daily before breakfast for 4 weeks. Treatment was extended for a further 4 weeks if the oesophagitis had not healed. RESULTS: After 4 weeks complete healing of the reflux oesophagitis was seen in 78% of protocol-correct patients given pantoprazole 40 mg daily (n = 86), and in 72% in the 80 mg (n = 87) group. The cumulative healing rates after 8 weeks were 95 and 94%, respectively (P > 0.05, Cochran-Mantel-Haenszel), and time until healing of oesophagitis comparable in both groups. Differences between doses were also not significant in an intention-to-treat analysis. Both dosing schedules were well tolerated and the patients experienced remarkable symptom relief. No adverse event or changes in laboratory values of clinical significance could definitely be ascribed to the trial medication. CONCLUSION: The 40 mg pantoprazole dosage is comparable to 80 mg in reflux oesophagitis, both in efficacy and tolerability.