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1.
Infect Dis Ther ; 12(9): 2269-2287, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37751015

RESUMO

INTRODUCTION: We assessed effects of AZD7442 (tixagevimab/cilgavimab) on deaths from any cause or hospitalizations due to coronavirus disease 2019 (COVID-19) and symptom severity and longer-term safety in the TACKLE adult outpatient treatment study. METHODS: Participants received 600 mg AZD7442 (n = 452) or placebo (n = 451) ≤ 7 days of COVID-19 symptom onset. RESULTS: Death from any cause or hospitalization for COVID-19 complications or sequelae through day 169 (key secondary endpoint) occurred in 20/399 (5.0%) participants receiving AZD7442 versus 40/407 (9.8%) receiving placebo [relative risk reduction (RRR) 49.1%; 95% confidence interval (CI) 14.5, 69.7; p = 0.009] or 50.7% (95% CI 17.5, 70.5; p = 0.006) after excluding participants unblinded before day 169 for consideration of vaccination). AZD7442 reduced progression of COVID-19 symptoms versus placebo through to day 29 (RRR 12.5%; 95% CI 0.5, 23.0) and improved most symptoms within 1-2 weeks. Over median safety follow-up of 170 days, adverse events occurred in 174 (38.5%) and 196 (43.5%) participants receiving AZD7442 or placebo, respectively. Cardiac serious adverse events occurred in two (0.4%) and three (0.7%) participants receiving AZD7442 or placebo, respectively. CONCLUSIONS: AZD7442 was well tolerated and reduced hospitalization and mortality through 6 months, and symptom burden through 29 days, in outpatients with mild-to-moderate COVID-19. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT04723394. ( https://beta. CLINICALTRIALS: gov/study/NCT04723394 ).


Antibodies are proteins produced by the body's immune system to specifically combat foreign substances, such as viruses. Tixagevimab and cilgavimab are a pair of antibodies that bind to a specific part of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). When they bind to the virus, they reduce its ability to cause disease. These antibodies were tested in a clinical trial to see if they could prevent people with COVID-19 from being hospitalized or dying. Around 900 adults took part in this clinical trial. These people all had COVID-19 but were not sick enough to be in hospital. Half of this group were treated with a dose of tixagevimab and cilgavimab, given as two injections. The other half received a placebo (injections that look exactly like the tixagevimab and cilgavimab injections but contain no medicine). The study found that, over 6 months, people with COVID-19 who received tixagevimab and cilgavimab were less likely to need to go to hospital than people who received the placebo. They were also less likely to die of COVID-19. Tixagevimab and cilgavimab also helped to improve COVID-19 symptoms. People who received the antibodies saw their symptoms improve faster than people who received the placebo. They were also less likely to have symptoms that got worse. Most people felt better within 1­2 weeks of getting treatment. No safety issues were found with tixagevimab and cilgavimab compared with placebo.

2.
J Infect Dis ; 227(10): 1153-1163, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-36683419

RESUMO

BACKGROUND: AZD7442 is a combination of extended half-life, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific neutralizing monoclonal antibodies (tixagevimab and cilgavimab). METHODS: This phase 1, first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study evaluated AZD7442 administered intramuscularly (300 mg) or intravenously (300, 1000, or 3000 mg) in healthy adults (aged 18-55 years). The primary end point was safety and tolerability. Secondary end points included pharmacokinetics and antidrug antibodies. RESULTS: Between 18 August and 16 October 2020, a total of 60 participants were enrolled; 50 received AZD7442, and 10 received placebo. Adverse events (all of mild or moderate intensity) occurred in 26 participants (52.0%) in the AZD7442 groups and 8 (80.0%) in the placebo group. No infusion or injection site or hypersensitivity reactions occurred. Tixagevimab and cilgavimab had mean half-lives of approximately 90 days (range, 87.0-95.3 days for tixagevimab and 79.8--91.1 days for cilgavimab) and similar pharmacokinetic profiles over the 361-day study period. SARS-CoV-2-specific neutralizing antibody titers provided by AZD7442 were maintained above those in plasma from convalescent patients with coronavirus disease 2019 (COVID-19). CONCLUSIONS: AZD7442 was well tolerated in healthy adults, showing a favorable safety profile across all doses. Depending on the SARS-CoV-2 variant, pharmacokinetic analyses suggest the AZD7442 could offer protection for ≥6 months against symptomatic COVID-19 after a single 300-mg intramuscular administration. CLINICAL TRIALS REGISTRATION: NCT04507256.


Antibodies are proteins produced by the body in response to infections caused by microbes, including viruses. AZD7442 is a combination of 2 human antibodies, with an extended duration of effect, sourced from people who had recovered from coronavirus disease 2019 (COVID-19). These antibodies recognize a specific part (spike protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, and prevent the virus from infecting cells in the body. The current study evaluated the safety of AZD7442 in healthy volunteers. Sixty adults were given AZD7442 or placebo (salt solution) as injections into the muscle (300-mg dose) or infusions into a vein (300­3000-mg doses). The study did not find any safety issues with AZD7442, including at the highest dose. AZD7442 was measured in the blood 12 months after dosing, suggesting a long duration of protection. Following this study, AZD7442 was tested in larger clinical trials to investigate its potential in preventing and treating COVID-19. AZD7442 is currently authorized as treatment for outpatients with COVID-19 and as a preventive drug in people who may not respond well to COVID-19 vaccines and need additional protection (eg, those taking medications that dampen the immune system).


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Adulto , Meia-Vida , Anticorpos Monoclonais , Anticorpos Neutralizantes , Método Duplo-Cego , Anticorpos Antivirais
4.
Clin Infect Dis ; 76(7): 1247-1256, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-36411267

RESUMO

BACKGROUND: This phase 3 trial assessed AZD7442 (tixagevimab/cilgavimab) for post-exposure prophylaxis against symptomatic coronavirus disease 2019 (COVID-19). METHODS: Adults without prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or COVID-19 vaccination were enrolled within 8 days of exposure to a SARS-CoV-2-infected individual and randomized 2:1 to a single 300-mg AZD7442 dose (one 1.5-mL intramuscular injection each of tixagevimab and cilgavimab) or placebo. Primary end points were safety and first post-dose SARS-CoV-2 reverse-transcription polymerase chain reaction (RT-PCR)-positive symptomatic COVID-19 event before day 183. RESULTS: A total of 1121 participants were randomized and dosed (AZD7442, n = 749; placebo, n = 372). Median (range) follow-up was 49 (5-115) and 48 (20-113) days for AZD7442 and placebo, respectively. Adverse events occurred in 162 of 749 (21.6%) and 111 of 372 (29.8%) participants with AZD7442 and placebo, respectively, mostly mild/moderate. RT-PCR-positive symptomatic COVID-19 occurred in 23 of 749 (3.1%) and 17 of 372 (4.6%) AZD7442- and placebo-treated participants, respectively (relative risk reduction, 33.3%; 95% confidence interval [CI], -25.9 to 64.7; P = .21). In predefined subgroup analyses of 1073 (96%) participants who were SARS-CoV-2 RT-PCR-negative (n = 974, 87%) or missing an RT-PCR result (n = 99, 9%) at baseline, AZD7442 reduced RT-PCR-positive symptomatic COVID-19 by 73.2% (95% CI, 27.1 to 90.1) vs placebo. CONCLUSIONS: This study did not meet the primary efficacy end point of post-exposure prevention of symptomatic COVID-19. However, analysis of participants who were SARS-CoV-2 RT-PCR-negative or missing an RT-PCR result at baseline support a role for AZD7442 in preventing symptomatic COVID-19. Clinical Trials Registration. NCT04625972.


Assuntos
COVID-19 , Adulto , Humanos , COVID-19/prevenção & controle , SARS-CoV-2 , Profilaxia Pós-Exposição , Vacinas contra COVID-19
5.
Lancet Respir Med ; 10(10): 985-996, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688164

RESUMO

BACKGROUND: Early intramuscular administration of SARS-CoV-2-neutralising monoclonal antibody combination, tixagevimab-cilgavimab, to non-hospitalised adults with mild to moderate COVID-19 has potential to prevent disease progression. We aimed to evaluate the safety and efficacy of tixagevimab-cilgavimab in preventing progression to severe COVID-19 or death. METHODS: TACKLE is an ongoing, phase 3, randomised, double-blind, placebo-controlled study conducted at 95 sites in the USA, Latin America, Europe, and Japan. Eligible participants were non-hospitalised adults aged 18 years or older with a laboratory-confirmed SARS-CoV-2 infection (determined by RT-PCR or an antigen test) from any respiratory tract specimen collected 3 days or less before enrolment and who had not received a COVID-19 vaccination. A WHO Clinical Progression Scale score from more than 1 to less than 4 was required for inclusion and participants had to receive the study drug 7 days or less from self-reported onset of mild to moderate COVID-19 symptoms or measured fever. Participants were randomly assigned (1:1) to receive either a single tixagevimab-cilgavimab 600 mg dose (two consecutive 3 mL intramuscular injections, one each of 300 mg tixagevimab and 300 mg cilgavimab) or placebo. Randomisation was stratified (using central blocked randomisation with randomly varying block sizes) by time from symptom onset, and high-risk versus low-risk of progression to severe COVID-19. Participants, investigators, and sponsor staff involved in the treatment or clinical evaluation and monitoring of the participants were masked to treatment-group assignments. The primary endpoints were severe COVID-19 or death from any cause through to day 29, and safety. This study is registered with ClinicalTrials.gov, NCT04723394. FINDINGS: Between Jan 28, 2021, and July 22, 2021, 1014 participants were enrolled, of whom 910 were randomly assigned to a treatment group (456 to receive tixagevimab-cilgavimab and 454 to receive placebo). The mean age of participants was 46·1 years (SD 15·2). Severe COVID-19 or death occurred in 18 (4%) of 407 participants in the tixagevimab-cilgavimab group versus 37 (9%) of 415 participants in the placebo group (relative risk reduction 50·5% [95% CI 14·6-71·3]; p=0·0096). The absolute risk reduction was 4·5% (95% CI 1·1-8·0; p<0·0001). Adverse events occurred in 132 (29%) of 452 participants in the tixagevimab-cilgavimab group and 163 (36%) of 451 participants in the placebo group, and were mostly of mild or moderate severity. There were three COVID-19-reported deaths in the tixagevimab-cilgavimab group and six in the placebo group. INTERPRETATION: A single intramuscular tixagevimab-cilgavimab dose provided statistically and clinically significant protection against progression to severe COVID-19 or death versus placebo in unvaccinated individuals and safety was favourable. Treating mild to moderate COVID-19 earlier in the disease course with tixagevimab-cilgavimab might lead to more favourable outcomes. FUNDING: AstraZeneca.


Assuntos
Tratamento Farmacológico da COVID-19 , Adulto , Anticorpos Monoclonais/uso terapêutico , Método Duplo-Cego , Humanos , Pessoa de Meia-Idade , Pacientes Ambulatoriais , SARS-CoV-2 , Resultado do Tratamento
6.
N Engl J Med ; 386(23): 2188-2200, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35443106

RESUMO

BACKGROUND: The monoclonal-antibody combination AZD7442 is composed of tixagevimab and cilgavimab, two neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that have an extended half-life and have been shown to have prophylactic and therapeutic effects in animal models. Pharmacokinetic data in humans indicate that AZD7442 has an extended half-life of approximately 90 days. METHODS: In an ongoing phase 3 trial, we enrolled adults (≥18 years of age) who had an increased risk of an inadequate response to vaccination against coronavirus disease 2019 (Covid-19), an increased risk of exposure to SARS-CoV-2, or both. Participants were randomly assigned in a 2:1 ratio to receive a single dose (two consecutive intramuscular injections, one containing tixagevimab and the other containing cilgavimab) of either 300 mg of AZD7442 or saline placebo, and they were followed for up to 183 days in the primary analysis. The primary safety end point was the incidence of adverse events after a single dose of AZD7442. The primary efficacy end point was symptomatic Covid-19 (SARS-CoV-2 infection confirmed by means of reverse-transcriptase-polymerase-chain-reaction assay) occurring after administration of AZD7442 or placebo and on or before day 183. RESULTS: A total of 5197 participants underwent randomization and received one dose of AZD7442 or placebo (3460 in the AZD7442 group and 1737 in the placebo group). The primary analysis was conducted after 30% of the participants had become aware of their randomized assignment. In total, 1221 of 3461 participants (35.3%) in the AZD7442 group and 593 of 1736 participants (34.2%) in the placebo group reported having at least one adverse event, most of which were mild or moderate in severity. Symptomatic Covid-19 occurred in 8 of 3441 participants (0.2%) in the AZD7442 group and in 17 of 1731 participants (1.0%) in the placebo group (relative risk reduction, 76.7%; 95% confidence interval [CI], 46.0 to 90.0; P<0.001); extended follow-up at a median of 6 months showed a relative risk reduction of 82.8% (95% CI, 65.8 to 91.4). Five cases of severe or critical Covid-19 and two Covid-19-related deaths occurred, all in the placebo group. CONCLUSIONS: A single dose of AZD7442 had efficacy for the prevention of Covid-19, without evident safety concerns. (Funded by AstraZeneca and the U.S. government; PROVENT ClinicalTrials.gov number, NCT04625725.).


Assuntos
Antivirais , COVID-19 , Adulto , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/uso terapêutico , Antivirais/administração & dosagem , Antivirais/uso terapêutico , COVID-19/prevenção & controle , Método Duplo-Cego , Combinação de Medicamentos , Humanos , Injeções Intramusculares , SARS-CoV-2
7.
Int J Chron Obstruct Pulmon Dis ; 16: 1637-1646, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34113095

RESUMO

Background: Management of acute exacerbations of chronic obstructive pulmonary disease (COPD) is sometimes inadequate leading to either prolonged duration and/or an increased risk of recurrent exacerbations in the period following the initial event. Objective: To evaluate the safety and efficacy of inhaled nemiralisib, a phosphoinositide 3-kinase δ inhibitor, in patients experiencing an acute exacerbation of COPD. Patients and Methods: In this double-blind, placebo-controlled study, COPD patients (40-80 years, ≥10 pack-year smoking history, current moderate/severe acute exacerbation of COPD requiring standard-of-care treatment) were randomized to placebo or nemiralisib 12.5 µg, 50 µg, 100 µg, 250 µg, 500 µg, or 750 µg (ratio of 3:1:1:1:1:1:3; N=938) for 12 weeks with an exploratory 12-week follow-up period. The primary endpoint was change from baseline in post-bronchodilator FEV1 at week 12. Key secondary endpoints were rate of re-exacerbations, patient-reported outcomes (Exacerbations of Chronic Pulmonary Disease Tool, COPD Assessment Test, St George's Respiratory Questionnaire-COPD), plasma pharmacokinetics (PK) and safety/tolerability. Results: There was no difference in change from baseline FEV1 at week 12 between the nemiralisib and placebo treatment groups (posterior adjusted median difference, nemiralisib 750 µg and placebo: -0.004L (95% CrI: -0.051L to 0.042L)). Overall, there were also no differences between nemiralisib and placebo in secondary endpoints, including re-exacerbations. Plasma PK increased in a dose proportional manner. The most common adverse event for nemiralisib was post-inhalation cough which appeared to be dose-related. Conclusion: The addition of nemiralisib to standard-of-care treatment for 12 weeks did not improve lung function or re-exacerbations in patients with, and following an acute exacerbation of COPD. However, this study demonstrated that large clinical trials recruiting acutely exacerbating patients can successfully be conducted.


Assuntos
Fosfatidilinositol 3-Quinases , Doença Pulmonar Obstrutiva Crônica , Broncodilatadores/uso terapêutico , Método Duplo-Cego , Volume Expiratório Forçado , Humanos , Indazóis , Indóis , Oxazóis/farmacologia , Oxazóis/uso terapêutico , Fosfatidilinositol 3-Quinases/farmacologia , Fosfatidilinositol 3-Quinases/uso terapêutico , Piperazinas , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico
8.
Clin Ther ; 41(6): 1214-1220, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31076203

RESUMO

PURPOSE: Nemiralisib, a phosphoinositide 3-kinase δ inhibitor, is being investigated as an immunomodulatory agent with anti-inflammatory properties in chronic obstructive pulmonary disease. This study evaluated the pharmacokinetic (PK) properties and safety of a new formulation of nemiralisib that contains 0.4% magnesium stearate. METHODS: In this randomized, double-blind, parallel-group study, healthy individuals received a single dose of 500 or 750 µg of nemiralisib administered via the Ellipta dry powder inhaler (DPI) (n = 6 in each treatment group). Aerodynamic particle size distribution (APSD) data comparing previous and new formulations were available before the study. Serial PK analyses for plasma exposure and safety assessments were performed during the first 24 h after dosing, with follow-up measurements on days 3 and 6 in clinic. FINDINGS: APSD had increases of approximately 6-fold and 2-fold in very fine particle mass and fine particle mass over the previous (Diskus) formulation. In humans, systemic exposure (AUC) was greater after inhalation of 750 versus 500 µg of nemiralisib (AUC0-t: 17,200 h∙pg/mL; 95% CI, 10,900-27,200 h∙pg/mL and 13,100; 95% CI, 8130-21,000 h∙pg/mL, respectively). A low frequency of individual adverse events and no serious adverse events were reported after both doses. IMPLICATIONS: After single-dose inhalation of 500 and 750 µg of nemiralisib from the Ellipta DPI in healthy individuals, plasma PK data were well defined, and as predicted based on previous PK and APSD data, exposure was increased with the new formulation. Nemiralisib was well tolerated with no new safety issues identified. These data supported progression of nemiralisib to a Phase IIb study in patients with chronic obstructive pulmonary disease. ClinicalTrials.gov identifier: NCT03189589.


Assuntos
Inaladores de Pó Seco , Indazóis , Indóis , Oxazóis , Piperazinas , Administração por Inalação , Método Duplo-Cego , Humanos , Indazóis/administração & dosagem , Indazóis/efeitos adversos , Indazóis/sangue , Indazóis/farmacocinética , Indóis/administração & dosagem , Indóis/efeitos adversos , Indóis/sangue , Indóis/farmacocinética , Oxazóis/administração & dosagem , Oxazóis/efeitos adversos , Oxazóis/sangue , Oxazóis/farmacocinética , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/sangue , Piperazinas/farmacocinética
9.
N Engl J Med ; 376(7): 629-640, 2017 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-27959700

RESUMO

BACKGROUND: Osimertinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that is selective for both EGFR-TKI sensitizing and T790M resistance mutations in patients with non-small-cell lung cancer. The efficacy of osimertinib as compared with platinum-based therapy plus pemetrexed in such patients is unknown. METHODS: In this randomized, international, open-label, phase 3 trial, we assigned 419 patients with T790M-positive advanced non-small-cell lung cancer, who had disease progression after first-line EGFR-TKI therapy, in a 2:1 ratio to receive either oral osimertinib (at a dose of 80 mg once daily) or intravenous pemetrexed (500 mg per square meter of body-surface area) plus either carboplatin (target area under the curve, 5 [AUC5]) or cisplatin (75 mg per square meter) every 3 weeks for up to six cycles; maintenance pemetrexed was allowed. In all the patients, disease had progressed during receipt of first-line EGFR-TKI therapy. The primary end point was investigator-assessed progression-free survival. RESULTS: The median duration of progression-free survival was significantly longer with osimertinib than with platinum therapy plus pemetrexed (10.1 months vs. 4.4 months; hazard ratio; 0.30; 95% confidence interval [CI], 0.23 to 0.41; P<0.001). The objective response rate was significantly better with osimertinib (71%; 95% CI, 65 to 76) than with platinum therapy plus pemetrexed (31%; 95% CI, 24 to 40) (odds ratio for objective response, 5.39; 95% CI, 3.47 to 8.48; P<0.001). Among 144 patients with metastases to the central nervous system (CNS), the median duration of progression-free survival was longer among patients receiving osimertinib than among those receiving platinum therapy plus pemetrexed (8.5 months vs. 4.2 months; hazard ratio, 0.32; 95% CI, 0.21 to 0.49). The proportion of patients with adverse events of grade 3 or higher was lower with osimertinib (23%) than with platinum therapy plus pemetrexed (47%). CONCLUSIONS: Osimertinib had significantly greater efficacy than platinum therapy plus pemetrexed in patients with T790M-positive advanced non-small-cell lung cancer (including those with CNS metastases) in whom disease had progressed during first-line EGFR-TKI therapy. (Funded by AstraZeneca; AURA3 ClinicalTrials.gov number, NCT02151981 .).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Pemetrexede/administração & dosagem , Piperazinas/administração & dosagem , Acrilamidas , Adulto , Idoso , Idoso de 80 Anos ou mais , Compostos de Anilina , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Pemetrexede/efeitos adversos , Piperazinas/efeitos adversos , Platina/administração & dosagem , Adulto Jovem
10.
J Pharm Sci ; 99(9): 3901-22, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20602348

RESUMO

A solid-state approach to enable compounds in preclinical development is used by identifying an amorphous solid dispersion in a simple formulation to increase bioavailability. Itraconazole (ITZ) was chosen as a model crystalline compound displaying poor aqueous solubility and low bioavailability. Solid dispersions were prepared with different polymers (PVP K-12, K29/32, K90; PVP VA S-630; HPMC-P 55; and HPMC-AS HG) at varied concentrations (1:5, 1:2, 2:1, 5:1 by weight) using two preparation methods (evaporation and freeze drying). Physical characterization and stability data were collected to examine recommended storage, handling, and manufacturing conditions. Based on generated data, a 1:2 (w/w) ITZ/HPMC-P dispersion was selected for further characterization, testing, and scale-up. Thermal data and computational analysis suggest that it is a possible solid nanosuspension. The dispersion was successfully scaled using spray drying, with the materials exhibiting similar physical properties as the screening samples. A simple formulation of 1:2 (w/w) ITZ/HPMC-P dispersion in a capsule was compared to crystalline ITZ in a capsule in a dog bioavailability study, with the dispersion being significantly more bioavailable. This study demonstrated the utility of using an amorphous solid form with desirable physical properties to significantly improve bioavailability and provides a viable strategy for evaluating early drug candidates.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacocinética , Itraconazol/química , Itraconazol/farmacocinética , Animais , Disponibilidade Biológica , Cristalização , Cães , Estabilidade de Medicamentos , Difração de Pó , Solubilidade , Difração de Raios X
11.
J Pharmacol Toxicol Methods ; 52(1): 83-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15914033

RESUMO

INTRODUCTION: The ICH guideline S7A recommends that the effects of drugs on the respiratory system are evaluated in laboratory mammals prior to administration in man. Previously, animals have been placed in plethysmography chambers for short durations. This study investigates the possibility of restraining animals in chambers for a longer duration to assess respiratory function over extended periods. METHODS: Respiratory function in conscious rats was assessed using plethysmography chambers where the rat body was enclosed in a sealed chamber while the head was free. Thoracic movements were measured by pressure transducers linked to a Buxco amplifier system and respiratory parameters were captured and analyzed by the Notocord HEM data acquisition system. Each animal was subjected to 5 acclimatization sessions of escalating duration (1, 2, 4, 5, and 6 hours (h)) over 5 days prior to testing, with a baseline recording session conducted the day prior to dosing. Animals (8 males/group) were dosed subcutaneously with saline or bethanecol (3, 10, or 30 mg/kg) and placed in the chambers for 6 h of continuous recording. Additionally, a recording session was conducted at 24 h post-dose. RESULTS: Subcutaneous administration of 30 mg/kg bethanecol decreased respiration rate by up to 33% during the first 1.5 h post-dose and increased tidal volume by up to 46% from 0.25 to 1.25 h post-dose when compared to vehicle group data. A decrease in minute volume of up to 33% was observed 0.25 h following administration of the 10 and 30 mg/kg doses. DISCUSSION: These data show a respiratory depression caused by the cholinergic agonist bethanecol, an effect partially compensated for by an increase in tidal volume. This also demonstrates the ability to continuously restrain and record respiratory parameters in conscious rats for up to 6 h without any negative impact on the quality of the data.


Assuntos
Betanecol/toxicidade , Avaliação Pré-Clínica de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Agonistas Muscarínicos/toxicidade , Fenômenos Fisiológicos Respiratórios/efeitos dos fármacos , Animais , Injeções Subcutâneas , Masculino , Pletismografia Total/métodos , Ratos , Ratos Sprague-Dawley , Restrição Física , Volume de Ventilação Pulmonar/efeitos dos fármacos
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