Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
1.
J Aerosol Med Pulm Drug Deliv ; 28(6): 486-97, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26372467

ABSTRACT

BACKGROUND: Two studies were undertaken to characterize the maximal effort inhalation profiles of healthy subjects and patients with asthma or chronic obstructive pulmonary disease (COPD) through a moderate-resistance dry powder inhaler (DPI). Correlations between inhaler-specific inhalation characteristics and inhaler-independent lung function parameters were investigated. METHODS: Healthy subjects (n = 15), patients with mild, moderate, or severe asthma (n = 45), and patients with mild, moderate, severe, or very-severe COPD (n = 60) were included in the studies. Inhalation pressure drop versus time profiles were recorded using an instrumented ELLIPTA® DPI or bespoke resistor component with equivalent resistivity. Inhaler-independent lung function assessments included pharyngometry, spirometry, plethysmography, and diffusion. RESULTS: For the inhaler-specific inhalation profiles, the mean maximal effort peak inspiratory flow rates (PIFRs) varied across the subgroups from 65.8-110.6 L/min (range: 41.6-142.9). Peak pressure drop, PIFR, inhaled volume, and average inhalation flow rate (primary endpoints) did not differ markedly between healthy subjects and patients with asthma or mild COPD. Moderate, severe, and very-severe COPD patients demonstrated lower mean peak pressure drops, PIFRs and inhaled volumes, which tended to decrease with increasing COPD severity. Severe and very-severe COPD patients demonstrated shorter mean inhalation times compared with all other participants. Inhaler-independent lung function parameters were consistent with disease severity, and statistically significant (p < 0.05) strong correlations (R > 0.7) with components of the inhaler-specific inhalation profiles were observed in the COPD cohort; correlations in the asthma cohort tended to be weaker. CONCLUSIONS: All participants achieved a maximal effort PIFR ≥ 41.6 L/min through the moderate resistance of the ELLIPTA inhaler. Patients with asthma achieved similar inhalation profiles to healthy subjects, but increasing COPD severity tended to reduce a patient's inhalation capability. Correlation analyses suggest that some lung function parameters may be a useful indicator of ability to inhale efficiently through a moderate-resistance DPI, such as the ELLIPTA inhaler.


Subject(s)
Asthma/drug therapy , Bronchodilator Agents/administration & dosage , Drug Delivery Systems/instrumentation , Dry Powder Inhalers , Lung/physiopathology , Pulmonary Disease, Chronic Obstructive/drug therapy , Administration, Inhalation , Adult , Aerosols , Aged , Asthma/diagnosis , Asthma/physiopathology , Equipment Design , Female , Humans , Inhalation , Male , Middle Aged , Powders , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/physiopathology , Severity of Illness Index , Young Adult
2.
Article in English | MEDLINE | ID: mdl-25565796

ABSTRACT

BACKGROUND: Umeclidinium and vilanterol, long-acting bronchodilators for the treatment of chronic obstructive pulmonary disease, are primarily eliminated via the hepatic route; however, severe renal impairment may adversely affect some elimination pathways other than the kidney. OBJECTIVES: To evaluate the effect of severe renal impairment on the pharmacokinetics of umeclidinium and umeclidinium/vilanterol. METHODS: Nine patients with severe renal impairment (creatinine clearance <30 mL/min) and nine matched healthy volunteers received a single dose of umeclidinium 125 µg; and after a 7- to 14-day washout, a single dose of umeclidinium/vilanterol 125/25 µg. RESULTS: No clinically relevant increases in plasma umeclidinium or vilanterol systemic exposure (area under the curve or maximum observed plasma concentration) were observed following umeclidinium 125 µg or umeclidinium/vilanterol 125/25 µg administration. On average, the amount of umeclidinium excreted in 24 hours in urine (90% confidence interval) was 88% (81%-93%) and 89% (81%-93%) lower in patients with severe renal impairment compared with healthy volunteers following umeclidinium 125 µg and umeclidinium/vilanterol 125/25 µg administration, respectively. Treatments were well tolerated in both populations. CONCLUSION: Umeclidinium 125 µg or umeclidinium/vilanterol 125/25 µg administration to patients with severe renal impairment did not demonstrate clinically relevant increases in systemic exposure compared with healthy volunteers. No dose adjustment for umeclidinium and umeclidinium/vilanterol is warranted in patients with severe renal impairment.


Subject(s)
Adrenergic beta-2 Receptor Agonists/pharmacokinetics , Benzyl Alcohols/pharmacokinetics , Bronchodilator Agents/pharmacokinetics , Chlorobenzenes/pharmacokinetics , Kidney Diseases/metabolism , Muscarinic Antagonists/pharmacokinetics , Quinuclidines/pharmacokinetics , Administration, Inhalation , Adrenergic beta-2 Receptor Agonists/administration & dosage , Adrenergic beta-2 Receptor Agonists/adverse effects , Adult , Aged , Area Under Curve , Benzyl Alcohols/administration & dosage , Benzyl Alcohols/adverse effects , Bronchodilator Agents/administration & dosage , Bronchodilator Agents/adverse effects , Chlorobenzenes/administration & dosage , Chlorobenzenes/adverse effects , Czech Republic , Drug Combinations , Dry Powder Inhalers , Female , Humans , Hungary , Kidney Diseases/diagnosis , Male , Middle Aged , Muscarinic Antagonists/administration & dosage , Muscarinic Antagonists/adverse effects , Quinuclidines/administration & dosage , Quinuclidines/adverse effects , Renal Elimination , Severity of Illness Index , Single-Blind Method
3.
Pulm Pharmacol Ther ; 29(1): 49-57, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25020273

ABSTRACT

INTRODUCTION: The long-acting muscarinic antagonist umeclidinium (UMEC) and the combination of UMEC with the long-acting beta2 agonist vilanterol (VI) are approved maintenance treatments for chronic obstructive pulmonary disease in the US and EU. OBJECTIVES: This study investigated the effect of UMEC and UMEC/VI on the QT interval corrected using Fridericia's correction (QTcF) following a 10-day treatment period. METHODS: Randomized, placebo- and moxifloxacin-controlled, 4-period incomplete block crossover study of healthy non-smokers (n = 103). All treatments were double blind, except for moxifloxacin/moxifloxacin placebo controls which were single blinded. Subjects were randomized to a treatment sequence which consisted of 4 of 5 regimens. Each regimen consisted of once-daily doses on Days 1-10 via the ELLIPTA™ dry powder inhaler and a single tablet on Day 10 of the following: placebo + placebo; placebo + moxifloxacin; UMEC 500 µg + placebo; UMEC/VI 125/25 µg (delivered dose: 113/22 µg) + placebo; UMEC/VI 500/100 µg + placebo. QT interval, additional cardiac parameters, pharmacokinetics, pharmacodynamics and safety were assessed. RESULTS: No clinically significant changes from baseline in QTcF occurred with UMEC 500 µg and UMEC/VI 125/25 µg compared with placebo, however, there was a change in QTcF from baseline of 6.4 ms (90% confidence interval [CI]: 4.3, 8.5) at 10 min and 8.2 ms (90%: 6.2, 10.2) at 30 min post dose following UMEC/VI 500/100 µg compared with placebo. On Day 10, categorical analysis demonstrated absolute QTcF values >450-480 ms for UMEC/VI 125/25 µg (1 subject) and moxifloxacin (3 subjects), and a change from baseline QTcF of >30-60 ms for UMEC/VI 125/25 µg, UMEC 500/100 µg and placebo (1 subject each) and moxifloxacin (2 subjects). On Day 10, the mean change from baseline in heart rate was increased with UMEC/VI 125/25 µg and UMEC 500/100 µg compared with placebo with the maximum increase occurring at 10 min post dose (8.4 bpm [90% CI: 7.0, 9.8] for UMEC/VI 125/25 µg; 20.3 bpm [90% CI: 18.9, 21.7] for UMEC/VI 500/100 µg); after this timepoint, heart rate rapidly returned to normal levels. UMEC and VI systemic exposures following UMEC/VI 500/100 µg were >4-fold higher than those following UMEC/VI 125/25 µg. All treatments were generally well tolerated in terms of adverse events, laboratory, vital signs and electrocardiogram data; the proportion of subjects with any adverse event was similar across treatments arms (39-59%).. CONCLUSION: There was no clinically significant effect on QTcF observed following 10-days' treatment with inhaled UMEC/VI 125/25 µg or UMEC 500 µg compared with placebo. The supratherapeutic dose of UMEC/VI 500/100 µg prolonged QTcF by 6.4 ms (90% CI: 4.3, 8.5) at 10 min and 8.2 ms (90% CI: 6.2, 10.2) at 30 min compared with placebo, following which QTcF interval difference from placebo declined rapidly..


Subject(s)
Adrenergic beta-2 Receptor Agonists/adverse effects , Benzyl Alcohols/adverse effects , Chlorobenzenes/adverse effects , Muscarinic Antagonists/adverse effects , Quinuclidines/adverse effects , Administration, Inhalation , Adrenergic beta-2 Receptor Agonists/administration & dosage , Adult , Benzyl Alcohols/administration & dosage , Chlorobenzenes/administration & dosage , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Drug Combinations , Dry Powder Inhalers , Female , Fluoroquinolones/adverse effects , Heart Rate/drug effects , Humans , Long QT Syndrome/chemically induced , Male , Middle Aged , Moxifloxacin , Muscarinic Antagonists/administration & dosage , Quinuclidines/administration & dosage , Single-Blind Method , Young Adult
4.
Clin Ther ; 36(7): 1016-1027.e2, 2014 Jul 01.
Article in English | MEDLINE | ID: mdl-24947493

ABSTRACT

BACKGROUND: The long-acting muscarinic antagonist umeclidinium (UMEC) is approved as a monotherapy, and in combination with the long-acting ß2-agonist vilanterol (VI), as a once-daily inhaled maintenance bronchodilator therapy for chronic obstructive pulmonary disease in the US and EU; they are not indicated for the treatment of asthma. Preclinical and clinical data suggest that UMEC and VI are predominantly eliminated by the liver. OBJECTIVES: The objectives of the study were to evaluate the effects of moderate hepatic impairment on the plasma and urinary pharmacokinetic properties of each drug, and on the tolerability of inhalational UMEC/VI 125/25 µg and UMEC 125 µg. METHODS: This open-label, nonrandomized study was conducted in patients with moderate hepatic impairment (Child-Pugh score, 7-9) and in healthy volunteers (control). Patients and volunteers were administered a single dose of UMEC/VI 125/25 µg, and, after a 7- to 14-day washout period, repeat-dose UMEC 125 µg once daily for 7 days. Primary end points were the plasma pharmacokinetic properties of single- and repeat-dose UMEC and VI. Secondary end points were the urinary pharmacokinetic properties of UMEC, and the tolerability of each treatment. RESULTS: All 18 enrolled patients and volunteers (12 men, 6 women; mean age, 53.6 years) completed the study. Mean systemic exposures of UMEC and VI were similar or numerically lower in patients with moderate hepatic impairment compared with those in healthy volunteers, but the differences were not clinically significant. UMEC accumulations with 7-day dosing of UMEC were similar between patients with moderate hepatic impairment and healthy volunteers. UMEC/VI 125/25 µg and UMEC 125 µg were well-tolerated, with no safety concerns identified. CONCLUSIONS: The administration of UMEC/VI 125/25 µg or UMEC 125 µg in patients with moderate hepatic impairment did not result in clinically relevant increases in UMEC or VI exposures compared with those in healthy volunteers. Based on these findings, no dose adjustment for UMEC/VI or UMEC is warranted in patients with moderate hepatic impairment.


Subject(s)
Benzyl Alcohols/administration & dosage , Benzyl Alcohols/pharmacokinetics , Chlorobenzenes/administration & dosage , Chlorobenzenes/pharmacokinetics , Liver Diseases/blood , Liver Diseases/urine , Quinuclidines/administration & dosage , Quinuclidines/pharmacokinetics , Administration, Inhalation , Adolescent , Adult , Aged , Case-Control Studies , Drug Combinations , Female , Humans , Male , Middle Aged , Young Adult
5.
Gastroenterology ; 145(6): 1253-61.e1-3, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23954313

ABSTRACT

BACKGROUND & AIMS: Alterations in central corticotropin-releasing factor signaling pathways have been implicated in the pathophysiology of anxiety disorders and irritable bowel syndrome (IBS). We aimed to characterize the effects of the corticotropin-releasing factor receptor 1 (CRF-R1) antagonist, GW876008, on brain and skin conductance responses during acquisition and extinction of conditioned fear to the threat of abdominal pain in subjects with IBS and healthy individuals (controls). METHODS: We performed a single-center, randomized, double-blind, 3-period crossover study of 11 women with IBS (35.50 ± 12.48 years old) and 15 healthy women (controls) given a single oral dose (20 mg or 200 mg) of the CRF-R1 antagonist or placebo. Blood-oxygen level-dependent responses were analyzed using functional magnetic resonance imaging in a tertiary care setting. RESULTS: Controls had greater skin conductance responses during acquisition than extinction, validating the fear-conditioning paradigm. In contrast, during extinction, women with IBS had greater skin conductance responses than controls-an effect normalized by administration of a CRF-R1 antagonist. Although the antagonist significantly reduced activity in the thalamus in patients with IBS and controls during acquisition, the drug produced greater suppression of blood-oxygen level-dependent activity in a wide range of brain regions in IBS patients during extinction, including the medial prefrontal cortex, pons, hippocampus, and anterior insula. CONCLUSIONS: Although CRF signaling via CRF-R1 is involved in fear acquisition and extinction learning related to expected abdominal pain in patients with IBS and controls, this system appears to be up-regulated in patients with IBS. This up-regulation might contribute to the previously reported abnormal brain responses to expected abdominal pain.


Subject(s)
Anxiety Disorders/physiopathology , Corticotropin-Releasing Hormone/physiology , Extinction, Psychological/physiology , Irritable Bowel Syndrome/physiopathology , Receptors, Corticotropin-Releasing Hormone/physiology , Signal Transduction/physiology , Abdominal Pain/physiopathology , Abdominal Pain/psychology , Adult , Anxiety Disorders/psychology , Brain/physiology , Brain Mapping , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Fear/physiology , Fear/psychology , Female , Galvanic Skin Response/drug effects , Galvanic Skin Response/physiology , Humans , Middle Aged , Pyrazoles/pharmacology , Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors , Receptors, Corticotropin-Releasing Hormone/drug effects , Signal Transduction/drug effects
6.
Article in English | MEDLINE | ID: mdl-23569370

ABSTRACT

BACKGROUND: The combination of umeclidinium (UMEC), a long-acting muscarinic receptor antagonist, and vilanterol (VI), a selective long-acting ß2 agonist, is in development for the treatment of chronic obstructive pulmonary disease (COPD). This study evaluated the pharmacokinetics, safety and tolerability, and pharmacodynamics of once-daily, inhaled UMEC and UMEC/VI when co-administered with oral verapamil, a moderate P-glycoprotein transporter and moderate cytochrome P450 3A4 (CYP3A4) inhibitor frequently used by patients with COPD and cardiovascular comorbidities. METHODS: Subjects were randomized to one of two 13-day treatment regimens: UMEC 500 µg or UMEC 500 µg/VI 25 µg. All subjects received a single tablet containing 240 mg verapamil on each of days 9-13. RESULTS: Repeat doses of UMEC and UMEC/VI in combination with and without verapamil were safe and well tolerated. There was no increase in systemic exposure of UMEC when administered in combination with VI compared to UMEC alone. UMEC maximum concentration was similar with or without verapamil; a moderate increase in UMEC area under the curve (approximately 1.4-fold) was observed with verapamil. Verapamil did not increase systemic exposure to VI following administration of the UMEC/VI combination. CONCLUSION: Administration of UMEC and UMEC/VI combination was well tolerated and did not show clinically relevant increases in systemic exposure for either drug. The UMEC/VI combination is unlikely to have a clinically meaningful drug-drug interaction with moderate P-glycoprotein transporter and CYP3A4 inhibitor drugs.


Subject(s)
Adrenergic beta-2 Receptor Agonists/therapeutic use , Benzyl Alcohols/therapeutic use , Chlorobenzenes/therapeutic use , Muscarinic Antagonists/therapeutic use , Pulmonary Disease, Chronic Obstructive/drug therapy , Quinuclidines/therapeutic use , Vasodilator Agents/therapeutic use , Verapamil/therapeutic use , Administration, Oral , Adolescent , Adrenergic beta-2 Receptor Agonists/blood , Adult , Aged , Benzyl Alcohols/blood , Chlorobenzenes/blood , Drug Combinations , Dry Powder Inhalers , Female , Heart Rate , Humans , Male , Middle Aged , Muscarinic Antagonists/blood , Potassium/blood , Quinuclidines/blood , Vasodilator Agents/blood , Verapamil/blood , Young Adult
7.
Eur J Pharmacol ; 701(1-3): 40-8, 2013 Feb 15.
Article in English | MEDLINE | ID: mdl-23276660

ABSTRACT

To characterise the safety, tolerability, pharmacodynamics (bronchodilatory effect) and pharmacokinetics of inhaled umeclidinium in patients with chronic obstructive pulmonary disease (COPD). The first investigation was a single dose, randomised, double-blind, placebo-controlled study (clinicaltrials.gov: NCT00515502) in which ipratropium bromide-sensitive patients received umeclidinium (250µg, 500µg, and 1000µg), tiotropium bromide 18µg or placebo. Patients were randomised to receive four out of five possible treatments as an incomplete block four-way cross-over. A subsequent study (clinicaltrials.gov: NCT700732472) was focused on assessment of safety, tolerability and pharmacokinetics of umeclidinium (250µg and 1000µg) administered once-daily for 7 days in a randomised, double-blind, placebo-controlled, parallel-group design. Of the 24 patients randomised for the single dose study, 20 completed; 31 out of 38 patients completed the repeat dose study. Most adverse events were mild-to-moderate and transient. Examination of heart rate, QTc interval, blood pressure and clinical laboratory assessments raised no concern over the safety of umeclidinium. Evidence of pharmacology was demonstrated in first study by statistically significant increases in specific airway conductance (sGaw) for up to 24h for all active treatments compared with placebo. Increases in forced expiratory volume in 1s were also observed. Pharmacokinetic analysis demonstrated that maximum observed plasma umeclidinium concentration (Cmax) was reached rapidly (time to Cmax: ∼5-15min) after single and repeat doses; 1.5-1.9-fold accumulation was observed after repeat-dosing. Single and repeat doses of umeclidinium were well tolerated and produced clinically relevant lung function improvements over 24h in patients with COPD.


Subject(s)
Pulmonary Disease, Chronic Obstructive/drug therapy , Quinuclidines/administration & dosage , Quinuclidines/therapeutic use , Administration, Inhalation , Aged , Drug Administration Schedule , Female , Heart Rate/drug effects , Humans , Male , Middle Aged , Quinuclidines/adverse effects , Quinuclidines/pharmacokinetics , Safety
8.
PLoS One ; 7(12): e50716, 2012.
Article in English | MEDLINE | ID: mdl-23284643

ABSTRACT

UNLABELLED: Umeclidinium bromide (GSK573719; UMEC), a new long-acting muscarinic receptor antagonist (LAMA), is in development with vilanterol (GW642444; VI), a selective long-acting ß(2) agonist (LABA), as a once-daily inhaled combination therapy for the treatment of chronic obstructive pulmonary disease (COPD). A single dose healthy volunteer study was conducted to assess the safety and tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of inhaled umeclidinium (500 µg) and vilanterol (50 µg) when administered separately and in combination using a novel dry powder inhaler (NDPI). Co-administration of single inhaled doses of umeclidinium and vilanterol to healthy Japanese subjects was well tolerated and not associated with meaningful changes in systemic exposure or PD effects compared with administration of either compound individually. Pharmacokinetic assessments showed rapid absorption for both drugs (Tmax = 5 min for both umeclidinium and vilanterol) followed by rapid elimination with median tlast of 4-5 h for umeclidinium and median tlast of 1.5-2.0 h for vilanterol. Assessments of pharmacokinetic interaction were inconclusive since for umeclidinium, Cmax following combination was higher than umeclidinium alone but not AUC whereas for vilanterol, AUC following combination was higher than vilanterol alone but not Cmax. There were no obvious trends observed between individual maximum supine heart rate and umeclidinium Cmax or vilanterol Cmax when delivered as umeclidinium 500 µg and vilanterol 50 µg combination or when delivered as umeclidinium or vilanterol alone. TRIAL REGISTRATION: Clinicaltrials.gov NCT00976144.


Subject(s)
Benzyl Alcohols/adverse effects , Benzyl Alcohols/pharmacokinetics , Chlorobenzenes/adverse effects , Chlorobenzenes/pharmacokinetics , Quinuclidines/adverse effects , Quinuclidines/pharmacokinetics , Adrenergic beta-2 Receptor Agonists/administration & dosage , Adrenergic beta-2 Receptor Agonists/adverse effects , Adrenergic beta-2 Receptor Agonists/pharmacokinetics , Adrenergic beta-2 Receptor Agonists/pharmacology , Adult , Aged , Benzyl Alcohols/administration & dosage , Benzyl Alcohols/pharmacology , Chlorobenzenes/administration & dosage , Chlorobenzenes/pharmacology , Cross-Over Studies , Double-Blind Method , Drug Interactions , Drug Therapy, Combination , Dry Powder Inhalers/instrumentation , Humans , Male , Middle Aged , Muscarinic Antagonists/administration & dosage , Muscarinic Antagonists/adverse effects , Muscarinic Antagonists/pharmacokinetics , Muscarinic Antagonists/pharmacology , Patient Safety , Quinuclidines/administration & dosage , Quinuclidines/pharmacology , Young Adult
9.
J Neurosci ; 31(35): 12491-500, 2011 Aug 31.
Article in English | MEDLINE | ID: mdl-21880911

ABSTRACT

Alterations in corticotropin-releasing factor (CRF) signaling pathways have been implicated in irritable bowel syndrome (IBS) pathophysiology. We aimed to (1) determine the effect of the selective CRF receptor 1 antagonist (CRF(1)) GW876008 relative to placebo, on regional activation and effective connectivity of a stress-related emotional-arousal circuit during expectation of abdominal pain using functional magnetic resonance imaging in human subjects with a diagnosis of IBS and healthy controls (HCs), and (2) examine GW876008 effects on state-trait anxiety and hypothalamic-pituitary-adrenal (HPA) axis response. Although there were no drug-related effects on peripheral HPA activity, significant central effects were observed in brain regions associated with the stress response. Effective connectivity analysis showed drug-induced normalizations between key regions of the emotional-arousal circuit in patients. During pain expectation, orally administered GW876008 relative to placebo produced significant blood oxygen level-dependent (BOLD) signal reductions in the amygdala, hippocampus, insula, anterior cingulate, and orbitomedial prefrontal cortices across groups. Patients showed significantly greater BOLD responses in the left locus coeruleus and hypothalamus after placebo compared with HCs, and BOLD signal decreases in the left hypothalamus after drug. The inhibitory effects of GW876008 in the hypothalamus in patients were moderated by anxiety; patients having average and high levels of state anxiety showed drug-related BOLD decreases. GW876008 represents a novel tool for elucidating the neuronal mechanisms and circuitry underlying hyperactivation of CRF/CRF(1) signaling and its role in IBS pathophysiology. The unique state anxiety effects observed suggest a potential pathway for therapeutic benefit of CRF(1) receptor antagonism for patients with stress-sensitive disorders.


Subject(s)
Abdominal Pain , Brain Mapping , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Pyrazoles/therapeutic use , Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors , Stress, Psychological/drug therapy , Stress, Psychological/etiology , Abdominal Pain/complications , Abdominal Pain/pathology , Abdominal Pain/psychology , Administration, Oral , Adolescent , Adrenocorticotropic Hormone/blood , Adult , Brain/blood supply , Brain/drug effects , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Middle Aged , Neural Pathways/blood supply , Oxygen/blood , Pain Measurement , Pain Threshold/drug effects , Young Adult
10.
J Clin Pharmacol ; 50(3): 338-49, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19797535

ABSTRACT

Alvimopan is a novel, oral, peripherally acting mu-opioid receptor (PAM-OR) antagonist that blocks the effects of opioids on the gastrointestinal tract, without blocking opioid-induced analgesic effects. It is metabolized by gut microflora to an active amide-hydrolysis metabolite, which is equipotent to alvimopan. The objective of this study was to characterize the pharmacokinetics of alvimopan and metabolite before, during, and after administration of a short course of antibiotics in healthy adult participants. Simulations were conducted to determine the feasibility for this study. An open-label, sequential drug interaction study was conducted in 45 participants who received twice-daily dosing of alvimopan with and without ciprofloxacin. Metabolite concentrations were reduced by 99.2% (90% confidence interval: 98.8-99.5) in the presence of ciprofloxacin. The interaction occurred rapidly, and recovery was slow. The interaction may be of relevance for patients with relatively high metabolite plasma concentrations prior to antibiotic administration but of little relevance for patients with little or no plasma metabolite exposure initially. Administration of ciprofloxacin decreased alvimopan C(max) by 24%, which is of no clinical relevance. There was no effect of ciprofloxacin on alvimopan trough concentrations or AUC. Alvimopan was well tolerated.


Subject(s)
Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Gastrointestinal Agents/pharmacokinetics , Piperidines/pharmacokinetics , Receptors, Opioid, mu/antagonists & inhibitors , Administration, Oral , Adolescent , Adult , Anti-Bacterial Agents/administration & dosage , Area Under Curve , Blood Pressure/drug effects , Chromatography, High Pressure Liquid , Ciprofloxacin/administration & dosage , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Interactions , Female , Gastrointestinal Agents/administration & dosage , Gastrointestinal Agents/blood , Heart Rate/drug effects , Humans , Male , Middle Aged , Piperidines/administration & dosage , Piperidines/blood , Tandem Mass Spectrometry , Time Factors , Young Adult
11.
Am J Physiol Gastrointest Liver Physiol ; 294(5): G1114-9, 2008 May.
Article in English | MEDLINE | ID: mdl-18372395

ABSTRACT

beta(3)-Adrenoceptors(beta(3)-AR) are expressed by cholinergic myenteric neurons and beta(3)-AR agonists are effective in experimental models of diarrhea. Our aim was to explore the effects of a beta(3)-AR agonist, solabegron, on gastrointestinal transit, safety, bowel function, plasma somatostatin, and solabegron pharmacokinetics (PK) following single and multiple doses. In a single-center, double-blind, parallel-group trial, 36 healthy volunteers were randomized to oral solabegron (50 or 200 mg twice daily) or placebo. Transit was measured by a validated method ((99m)Tc-labeled egg meal and (111)In charcoal delivered to the colon via delayed-release capsule). Stool frequency, form, and ease of passage were measured on a validated daily diary; plasma somatostatin by radioimmunoassay and plasma solabegron and its active metabolite by validated liquid chromatography-tandem mass spectroscopy analysis followed by PK analysis using noncompartmental methods. There were no overall or dose-related effects of solabegron on gastric, small bowel, or colonic transit, plasma somatostatin levels, stool frequency, form, or ease of passage in healthy volunteers. Solabegron and active metabolite exposures (area under the curve and maximum serum concentration) at both dose levels were consistent with PK at similar doses in previous phase I studies. We concluded that 7 days of the beta(3)-AR agonist, solabegron, 50 or 200 mg twice daily, did not significantly alter gastrointestinal or colonic transit or bowel function. In this study, medication was generally well tolerated with few adverse events reported and no clinically significant changes in vital signs observed. Further studies on clinical efficacy, visceral sensitivity, and gastrointestinal transit are required in irritable bowel syndrome patients.


Subject(s)
Adrenergic beta-3 Receptor Agonists , Aniline Compounds/pharmacology , Benzoates/pharmacology , Defecation/drug effects , Gastrointestinal Transit/drug effects , Somatostatin/blood , Adult , Aniline Compounds/adverse effects , Aniline Compounds/pharmacokinetics , Antidiarrheals/adverse effects , Antidiarrheals/pharmacokinetics , Antidiarrheals/pharmacology , Area Under Curve , Benzoates/adverse effects , Benzoates/pharmacokinetics , Biphenyl Compounds , Dose-Response Relationship, Drug , Double-Blind Method , Feces/chemistry , Female , Gastrointestinal Transit/physiology , Headache/chemically induced , Humans , Male , Metabolic Clearance Rate
12.
J Acquir Immune Defic Syndr ; 33(5): 557-63, 2003 Aug 15.
Article in English | MEDLINE | ID: mdl-12902798

ABSTRACT

From a study of 71 HIV-1-infected patients receiving abacavir in combination with 1 of 5 different HIV-1 protease inhibitors (indinavir, ritonavir, saquinavir, nelfinavir, or amprenavir), we found that the baseline HIV-1 RNA levels were highly predictive of the viral decay rates. The baseline HIV-1 RNA levels were negatively correlated with the first phase viral decay rates (r = -0.77, P < 0.001) and positively correlated with the second phase viral decay rates (r = 0.68, P < 0.001). In addition, the first phase viral decay rate was positively correlated with CD4+ cell increases. No significant correlation was found between viral decay rates and longer term (24 weeks) virologic responses, and no difference in viral decay rates was found among the 5 study regimens. These data suggest that the potency of the 5 treatment regimens was similar and was not predictive of long-term virologic failure.


Subject(s)
Dideoxynucleosides/therapeutic use , HIV Infections/drug therapy , HIV Protease Inhibitors/therapeutic use , HIV-1/drug effects , Reverse Transcriptase Inhibitors/therapeutic use , Adolescent , Adult , CD4 Lymphocyte Count , Drug Therapy, Combination , Female , HIV Infections/immunology , HIV-1/isolation & purification , Humans , Male , Middle Aged , RNA, Viral/blood , Time Factors , Viral Load
SELECTION OF CITATIONS
SEARCH DETAIL
...