Administration Of Roflumilast Research Articles

Role of Impaired CFTR Function in Pathogenesis of Pneumonia Among Alcohol Users

INTRODUCTIONImpairment of mucociliary clearance (MCC) increases the risk of respiratory infections among excessive alcohol users. The mechanisms underlying this impact of alcohol on MCC are not currently understood. Our previous in vitro studies indicated that alcohol decreases ion transport via CFTR channels, the defective protein that causes cystic fibrosis. Here, we have attempted to validate these findings in vivo and test the hypothesis that alcohol‐induced CFTR dysfunction reduces airway surface hydration and mucus transport thereby impairing airway defense against inhaled bacterial pathogens, in particular Klebsiella pneumoniae, to which alcohol users are disproportionately susceptible. Since CFTR dysfunction correlates with reduced PKA‐dependent CFTR phosphorylation and channel gating due to increased cAMP degradation by phosphodiesterase‐4B (PDE4B) enzymes, we also tested the effects of PDE4 inhibitor, roflumilast, on CFTR function and bacterial clearance in alcohol‐fed rats.METHODSAge and gender‐matched rats (CFTR+/+) were pair‐fed with Lieber‐DeCarli alcohol diet or isocaloric control diet for 4 weeks and with K. pneumoniae (KP, ATCC 43816). Subsets of rats were randomly treated with vehicle/roflumilast (5mg/kg/day) by oral gavage starting 7 days before the end of the alcohol diet. CFTR activity was measured with nasal potential difference (NPD) and MCC was assayed with radiographic clearance of Tc99. Airway surface liquid (ASL), periciliary layer (PCL), and ciliary beat frequency (CBF) of excised trachea were quantified with micro‐optical coherence tomography (μOCT).RESULTSAlcohol administration reduced CFTR ion transport by NPD. Clearance of Tc99 label in 30 min indicated delayed MCC in alcohol‐treated rats. Trachea excised from alcohol‐treated rats exhibited significantly decreased PCL depth, but no meaningful differences in ASL or CBF. Roflumilast treatment significantly increased CFTR activity in both control and alcohol‐administered rats. Increased CFTR activation by roflumilast resulted in augmented PCL depth, reduced mucus viscosity and significantly accelerated MCT rate. Compared to controls, histopathological examination of lung sections from alcohol‐treated animals exhibited more severe evidence of multifocal pneumonia with edema, fibrin deposition and numerous bacteria in alveolar spaces. Ongoing studies are determining the impact of roflumilast treatment on bacterial clearance and severity of pneumonia by K. pneumoniae.CONCLUSIONSAlcohol‐induced defects in CFTR ion transport resulted in reduced airway surface hydration and delayed mucus clearance in rat airways that was associated with diminished ability to clear bacterial pathogens. Acquired (non‐genetic) CFTR dysfunction may be a suitable pharmacologic target to improve mucus clearance impaired by chronic alcohol use. Administration of roflumilast may boost lung host defense against bacterial pathogens and improve pneumonia outcomes in individuals affected by excessive alcohol use.Support or Funding InformationNIH 1R01AA027528

A Nonhuman Primate PET Study: Measurement of Brain PDE4 Occupancy by Roflumilast Using (R)-[11C]Rolipram

PurposePhosphodiesterase 4 (PDE4) inhibition in the brain has been reported to improve cognitive function in animal models. Therefore, PDE4 inhibitors are one of key targets potential for drug development. Investigation of brain PDE4 occupancy would help to understand the effects of PDE4 inhibition to cognitive functions. Roflumilast is a selective phosphodiesterase type 4 (PDE4) inhibitor used clinically for severe chronic obstructive pulmonary disease, but the effects to the brain have not been well investigated. In this study, we aimed to investigate whether roflumilast entered the brain and occupied PDE4 in nonhuman primates.ProceduresPositron emission tomography (PET) measurements with (R)-[11C]rolipram were performed at baseline and after intravenous (i.v.) administration of roflumilast (3.6 to 200 μg/kg) in three female rhesus monkeys. Arterial blood samples were taken to obtain the input function. Protein binding was measured to obtain the free fraction (fp) of the radioligand. Total distribution volume (VT) and VT/fp were calculated as outcome measures from two tissue compartment model. Lassen plot approach was taken to estimate the target occupancy.ResultsThe brain uptake of (R)-[11C]rolipram decreased after roflumilast administration. PDE 4 occupancy by roflumilast showed dose- and plasma concentration-dependent increase, although PDE4 occupancy did not reach 50 % even after the administration of up to 200 μg/kg of roflumilast, regardless of outcome measures, VT or VT/fp.ConclusionsThis PET study showed that the brain PDE4 binding was blocked to a certain extent after i.v. administration of clinical relevant doses of roflumilast in nonhuman primates. Further clinical PET evaluation is needed to understand the relationship between PDE4 inhibition and potential improvement of cognitive function in human subjects.

Roflumilast treatment inhibits lung carcinogenesis in benzo(a)pyrene-induced murine lung cancer model

Roflumilast, a potent and selective inhibitor of phosphodiesterase-4 (PDE4), has been used in treatment of COPD. PDE4 inhibitor is associated with inhibition of chronic airway inflammation, oxidative stress, and mesenchymal markers in B(a)P-induced lung tumors. The aim of this study was to assess whether roflumilast alone or added to inhaled budesonide might have dose-dependent inhibition on lung carcinogenesis induced by carcinogen B(a)P in mice. Female A/J mice were given a single dose of benzo(a)pyrene. Administration of roflumilast (1mg/kg or 5mg/kg) via oral gavage and aerosolized budesonide (2.25mg/ml) began 2 weeks post-carcinogen treatment and continued for 26 weeks. Tumor load was determined by averaging the total tumor volume in each group. Benzo(a)pyrene induced an average tumor size of 9.38 ± 1.75 tumors per mouse, with an average tumor load of 19.53 ± 3.81mm3. Roflumilast 5mg/kg treatment decreased (P < 0.05) tumor load per mouse compared to the B(a)P group. Roflumilast 5mg/kg treatment significantly increased the levels of cAMP in tumors with adjacent lung tissues (P < 0.05). The expression level of PDE4D gene was decreased by roflumilast 5mg/kg treatment, significantly (P < 0.05). Compared to the B(a)P exposure group, expression levels of HIF-1α and VEGFA were attenuated by roflumilast 5mg/kg treatment (P < 0.05). High-dose roflumilast can attenuate lung carcinogenesis in B(a)P-induced murine lung cancer model. The chemopreventive effect of roflumilast might be associated with inhibition of increased cAMP-mediated inflammatory process and markers of angiogenesis in tumor tissues.

The effects of roflumilast on the pancreas and remote organs in a cerulein-induced experimental acute pancreatitis model in rats.

Systemic damage in acute pancreatitis (AP) can be characterized by oxidative stress and the release of pro-inflammatory cytokines. Roflumilast has been shown to be a potent anti-inflammatory and antioxidant agent. In the present study, we aimed to investigate the effect of roflumilast in cerulein-induced AP. Thirty-two male rats were divided into four groups: group 1 (sham), group 2 (Roflumilast), group 3 (AP), and group 4 (AP+Roflumilast). AP was induced by injecting 4×75μg/kg of body weight at an interval of 1h. Rats were killed after 12h following the last cerulein administration. AP was confirmed by measuring the serum amylase level and inflammatory features. Morphological changes were observed in the pancreas. Amylase levels were higher in the AP and AP+Roflumilast groups than the sham and Roflumilast groups. The serum levels of TNF-α, IL-1β, and IL-6 increased in the AP group, whereas they decreased in the Roflumilast group. The total oxidant activity (TOA) was higher and the total antioxidant capacity (TAC) was lower in the AP group. The administration of roflumilast decreased the TOA and increased the TAC in comparison with the AP group (p<0.05 for both). Roflumilast significantly decreases oxidative stress and inflammatory mediators in the plasma, pancreas, and lung in cerulein-induced AP rats.

Study investigating pharmacokinetic interaction between theophylline and roflumilast in healthy adults

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. 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. 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. 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.

Supra-therapeutic doses of roflumilast have no effect on cardiac repolarization in healthy subjects

Objective: This study assesses the potential of the phosphodiesterase 4 inhibitor roflumilast to affect cardiac repolarization.Methods: In this randomized, placebo-controlled study (n = 80), 40 healthy subjects received moxifloxacin 400 mg p.o. (positive control for prolongation of QT/heart-rate corrected QT [QTc]) and another 40 received placebo. After a 1-day washout, subjects received placebo or ascending doses of roflumilast 500 (therapeutic dose), 750 or 1000 μg/day p.o., for 14, 7 and 14 days, respectively. QT intervals were measured and corrected for heart rate with a Fridericia algorithm (QTcF). The primary endpoint was the largest mean time-matched change in QTcF from baseline (day 1). Safety and tolerability were monitored.Results: Moxifloxacin gave a maximum time-matched change in QTcF versus baseline of 6.79 ms. Repeated administration of roflumilast 500 and 1000 μg resulted in maximum QTcF changes from baseline of -3.23 and -4.81 ms, respectively, confirming the absence of any QT/QTc prolongation at therapeutic and supra-therapeutic dosing. There were no changes in other electrocardiographic variables or time intervals, and roflumilast was well tolerated.Conclusions: Repeated administration of roflumilast at doses ≤ 1000 μg/day had no effect on cardiac repolarization or overall cardiac safety evaluations in healthy subjects.Clinical trial registration number: ISRCTN63818313

Lack of a pharmacokinetic interaction between steady-state roflumilast and single-dose midazolam in healthy subjects.

The aim of this study was to investigate the effects of roflumilast, an investigational PDE4 inhibitor for the treatment of COPD and asthma, on the pharmacokinetics of the CYP3A probe drug midazolam and its major metabolites. In an open, randomized (for midazolam treatment sequence) study, 18 healthy male subjects received single doses of midazolam (2 mg oral and 1 mg i.v., 1 day apart) alone, repeated doses of roflumilast (500 microg once daily for 14 days) alone, and repeated doses of roflumilast together with single doses of midazolam (2 mg oral and 1 mg i.v., 1 day apart). A comparison of clearance and peak and systemic exposure to midazolam following administration of roflumilast indicated no effect of roflumilast dosed to steady state on the pharmacokinetics of midazolam. Point estimates (90% CI) were 0.97 (0.84, 1.13) for the AUC of i.v. midazolam and 0.98 (0.82, 1.17) for that of oral midazolam with and without roflumilast. Therapeutic steady state concentrations of roflumilast and its N-oxide do not alter the disposition of the CYP3A substrate midazolam in healthy subjects. This finding suggests that roflumilast is unlikely to alter the clearance of drugs that are metabolized by CYP3A4.