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1.
Epilepsia ; 58(1): 51-59, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27869305

RESUMO

OBJECTIVE: To analyze occurrence of falls among patients with partial seizures, with/without secondarily generalized seizures (SGS), and primary generalized tonic-clonic seizures (PGTCS) in the perampanel phase III clinical studies. METHODS: Studies 304, 305, and 306 randomized subjects (≥12 years) with drug-resistant partial seizures (with/without SGS) to perampanel 2, 4, 8, or 12 mg or placebo for double-blind treatment. The adverse event (AE) of falls was analyzed in the Safety Analysis Set (N = 1480). Study 332 randomized subjects aged ≥12 years with a diagnosis of PGTCS into perampanel 8 mg or placebo groups for double-blind treatment. In a systematic review of reported falls in the study 332 Safety Analysis Set (N = 163), falls were queried to establish whether each was seizure related; subjects with falls resulting from a seizure were not included in this analysis. RESULTS: For studies 304/305/306, treatment-emergent falls occurred in 5.1% perampanel-treated versus 3.4% placebo-treated subjects with partial seizures. Exposure-adjusted rate for falls (falls/subject-month of exposure) was greater for total perampanel than for placebo (0.0175 vs. 0.0093) and was dose related for those receiving perampanel. In subjects with SGS, incidence of treatment-emergent falls was 4.3% in perampanel and 4.0% in placebo groups. Exposure-adjusted rates were 0.0169 and 0.0097 falls per subject-month of exposure in perampanel and placebo, respectively. For study 332, 2.5% perampanel-treated and 1.2% placebo-treated subjects with PGTCS had treatment-emergent falls that were not part of a seizure. Exposure-adjusted rates were 0.0169 and 0.0032 falls per subject-month of exposure in perampanel and placebo, respectively. SIGNIFICANCE: Results of the perampanel studies suggest that patients with epilepsy should be monitored due to the common risk of falls.


Assuntos
Acidentes por Quedas , Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Piridonas/uso terapêutico , Adolescente , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Resultado do Tratamento , Adulto Jovem
2.
Epilepsia ; 56(8): 1252-63, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26140524

RESUMO

OBJECTIVE: Perampanel, a selective, noncompetitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor antagonist, is indicated for adjunctive treatment of partial seizures in patients ≥12 years based on three phase III clinical studies. The perampanel U.S. Prescribing Information includes a boxed warning for serious psychiatric and behavioral adverse reactions. To provide context for this warning, detail on psychiatric and behavioral safety data from perampanel clinical studies is presented. METHODS: An analysis of pooled safety data from three phase III studies in patients with partial seizures is presented. Data from phase I and phase II studies in patients with and without epilepsy were also analyzed. Psychiatric and behavioral treatment-emergent adverse events (TEAEs) were evaluated according to Medical Dictionary for Regulatory Activities (MedDRA) terms, using "narrow" and "narrow-and-broad" standardized MedDRA queries (SMQs) for TEAEs suggestive of hostility/aggression. RESULTS: From the three phase III partial-seizure studies, the overall rate of psychiatric TEAEs was higher in the 8 mg (17.2%) and 12 mg (22.4%) perampanel groups versus placebo (12.4%). In the "narrow" SMQ, hostility/aggression TEAEs were observed in 2.8% for 8 mg and 6.3% for 12 mg perampanel groups, versus 0.7% of placebo patients. "Narrow-and-broad" SMQs for hostility/aggression TEAE rates were 12.3% for 8 mg and 20.4% for 12 mg perampanel groups, versus 5.7% for placebo; rates for events resulting in discontinuation were perampanel = 1.6% versus placebo = 0.7%. For events reported as serious AEs (SAEs), rates were perampanel = 0.7% versus placebo = 0.2%. In nonepilepsy patients, psychiatric TEAEs were similar between patients receiving perampanel and placebo. In phase I subjects/volunteers, all psychiatric TEAEs were mild or moderate. These analyses suggest that psychiatric adverse effects are associated with use of perampanel. SIGNIFICANCE: Patients and caregivers should be counseled regarding the potential risk of psychiatric and behavioral events with perampanel in patients with partial seizures; patients should be monitored for these events during treatment, especially during titration and at higher doses.


Assuntos
Agressão , Anticonvulsivantes/efeitos adversos , Epilepsias Parciais/tratamento farmacológico , Hostilidade , Transtornos Mentais/induzido quimicamente , Piridonas/efeitos adversos , Adolescente , Adulto , Criança , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Adulto Jovem
3.
Epilepsy Behav ; 35: 6-12, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24785428

RESUMO

RATIONALE: Perampanel is a selective AMPA receptor antagonist approved for adjunctive therapy in patients with refractory partial-onset seizures. Perampanel is metabolized primarily via CYP3A4, yet it has a relatively long half-life of 105h; it is, therefore, recommended that perampanel be given once daily (preferably at bedtime). Many patients occasionally have less-than-perfect adherence to their drug regimen, and given the known pharmacokinetic interactions of perampanel with commonly used enzyme-inducing antiepileptic drugs (EIAEDs), we explored the effects of a missed dose on steady-state perampanel plasma concentrations and the ramifications of "make up" doses in these patients. Although perampanel is approved for once-daily dosing, some clinicians may elect to give perampanel as a divided dose (i.e., twice daily), so we also sought to examine the pharmacokinetic impact of twice- versus once-daily dosing. METHODS: Pharmacokinetic simulations were performed using validated perampanel pharmacokinetic parameters, derived from 19 phase I studies in 606 subjects, to investigate the effect on perampanel plasma concentration of (1) missing a dose of perampanel followed by delayed replacement of the missed dose, (2) missing a dose followed by resumption of scheduled therapy, and (3) missing a dose in the presence/absence of carbamazepine. Simulations were done for a typical patient receiving an 8-mg once-daily or a 4-mg twice-daily dose using the nonlinear mixed effects program, NONMEM v7.2, in conjunction with PDx-pop v5. RESULTS: Our results corroborate that given the pharmacokinetic characteristics of perampanel, a missed dose is unlikely to cause as much fluctuation in plasma concentration as would be expected for a drug with a short half-life. Importantly, simulations suggest that supplementing a missed dose 6-12h later, followed by continuation of the regular schedule, may not result in any significant "spikes" in perampanel plasma concentrations. Simulations demonstrated that twice-daily dosing offered little advantage in further flattening the concentration-time profile of perampanel in the adherent patient. However, fluctuations in plasma concentrations are minimized by twice-daily dosing in patients receiving concomitant EIAEDs. CONCLUSIONS: These pharmacokinetic simulations suggest that the long half-life of perampanel may be advantageous in conferring a relatively smooth concentration-time profile with a once-daily or twice-daily dosing, even in the presence of concomitant EIAEDs. However, the results of the present study suggest that perampanel replacement is recommended for patients taking an EIAED to mitigate the potential risks associated with reduced exposure. Confirmation of the ultimate clinical impact of these findings will require further study.


Assuntos
Anticonvulsivantes , Epilepsias Parciais/sangue , Epilepsias Parciais/tratamento farmacológico , Piridonas , Anticonvulsivantes/sangue , Anticonvulsivantes/farmacocinética , Anticonvulsivantes/uso terapêutico , Pesquisa Biomédica , Carbamazepina/sangue , Carbamazepina/uso terapêutico , Simulação por Computador , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Masculino , Adesão à Medicação , Modelos Biológicos , Nitrilas , Farmacocinética , Piridonas/sangue , Piridonas/farmacocinética , Piridonas/uso terapêutico , Fatores de Tempo
4.
BMC Geriatr ; 13: 56, 2013 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-23742728

RESUMO

BACKGROUND: Treatment of Alzheimer's disease with acetylcholinesterase inhibitors can result in symptomatic benefits, but patients often show variable responses. The objective of this post hoc analysis was to investigate relationships between easily identifiable baseline characteristics/demographics and cognitive response in patients treated with either donepezil 23 mg/d or 10 mg/d and to identify factors potentially influencing response. METHODS: A post hoc analysis was conducted using data from a large, 24-week, randomized, double-blind, international study enrolling patients with moderate to severe Alzheimer's disease (baseline Mini-Mental State Examination [MMSE], 0-20) (NCT 00478205). Cognitive changes in subgroups of patients based on selected baseline and demographic characteristics were compared using the least squares mean changes in Severe Impairment Battery scores at Week 24. Univariate and multivariate analyses were also performed. RESULTS: Donepezil 23 mg/d provided statistically significant incremental cognitive benefits over donepezil 10 mg/d irrespective of baseline functional severity, measured by scores on the Alzheimer's Disease Cooperative Study-Activities of Daily Living-severe version (P < 0.05). When patients were categorized by baseline cognitive severity (MMSE score), significant benefits of donepezil 23 mg/d over 10 mg/d were seen in both subgroups when based on MMSE scores of 0-9 versus 10-20 (P < 0.02 and P < 0.01, respectively), and in the more severe subgroup when based on MMSE scores of 0-16 versus 17-20 (P < 0.0001 and P > 0.05). Statistically significant incremental cognitive benefits of donepezil 23 mg/d over 10 mg/d were also observed regardless of age, gender, weight, or prestudy donepezil 10 mg/d treatment duration (P < 0.05). In the multivariate analysis, the only significant interaction was between treatment and baseline MMSE score. CONCLUSIONS: The cognitive benefits of donepezil 23 mg/d over 10 mg/d were achieved regardless of the patient's age, gender, weight, duration of prior donepezil 10 mg/d, and functional severity. The influence of baseline cognitive severity on response seemed to be dependent on the level of impairment, with cognitive benefits of donepezil 23 mg/d over 10 mg/d most apparent in those patients at a more advanced stage of disease. These data may be useful in helping practicing physicians make informed decisions for their patients with advanced Alzheimer's disease.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/administração & dosagem , Transtornos Cognitivos/tratamento farmacológico , Indanos/administração & dosagem , Piperidinas/administração & dosagem , Índice de Gravidade de Doença , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/psicologia , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/psicologia , Donepezila , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
5.
J Patient Saf ; 17(2): e76-e83, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30672762

RESUMO

OBJECTIVE: Opioid analgesics are a mainstay for acute pain management, but postoperative opioid administration has risks. We examined the prevalence, risk factors, and consequences of opioid-related adverse drug events (ORADEs) in a previously opioid-free surgical population. METHODS: A retrospective, observational, cohort study using administrative, billing, clinical, and medication administration data from two hospitals. Data were collected for all adult patients who were opioid-free at admission, underwent surgery between October 1, 2015, and September 30, 2016, and received postoperative opioids. Potential ORADEs were determined based on inpatient billing codes or postoperative administration of naloxone. We determined independent predictors of ORADE development using multivariable logistic regression. We measured adjusted inpatient mortality, hospital costs, length of hospital stay, discharge destination, and readmission within 30 days for patients with and without ORADEs. RESULTS: Among 13,389 hospitalizations where opioid-free patients had a single qualifying surgery, 12,218 (91%) received postoperative opioids and comprised the study cohort. Of these, we identified 1111 (9.1%) with a potential ORADE. Independent predictors of ORADEs included older age, several markers of disease severity, longer surgeries, and concurrent benzodiazepine use. Opioid-related adverse drug events were strongly associated with the route and duration of opioids administered postoperatively: 18% increased odds per day on intravenous opioids. In analyses adjusted for several covariates, presence of an ORADE was associated with 32% higher costs of hospitalization, 45% longer postoperative length of stay, 36% lower odds of discharge home, and 2.2 times the odds of death. CONCLUSIONS: We demonstrate a high rate and severe consequences of potential ORADEs in previously opioid-free patients receiving postoperative opioids. Knowledge of risk factors and predictors of ORADEs can help develop targeted interventions to minimize the development of these potentially dangerous and costly events.


Assuntos
Analgésicos Opioides/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Adulto , Idoso , Estudos de Coortes , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
6.
Curr Med Res Opin ; 35(2): 283-289, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29799282

RESUMO

OBJECTIVES: Utilization of opioid-free analgesia (OFA) for post-surgical pain is a growing trend to counter the risks of opioid abuse and opioid-related adverse drug events (ORADEs). However, utilization patterns of OFA have not been examined. In this study, we investigated the utilization patterns and predictors of OFA in a surgical population in the United States. METHODS: Analysis of the Cerner Health Facts database (January 2011 to December 2015) was conducted to describe hospital and patient characteristics associated with OFA. Baseline characteristics, such as age, gender, race, discharge status, year of admission and chronic comorbidities at index admission were collected. Hospital characteristics and payer type at index admission were collected as reported in the electronic health record database. Descriptive statistics and logistic regression were used to identify statistically significant predictors of OFA on patient and institutional levels. RESULTS: The study identified 10,219 patients, from 187 hospitals, who received post-surgical OFA and 255,196 patients who received post-surgical opioids. OFA rates varied considerably by hospital. Patients more likely to receive OFA were older (OR = 1.06, 95% CI [1.03, 1.10]; p < .001), or had neurological disorders (OR = 1.24, 95% CI [1.10, 1.39]; p < .001), diabetes (OR = 1.20, 95% CI [1.08, 1.33]; p = .001) or psychosis (OR = 1.18, 95% CI [1.01, 1.37]; p = .030). Patients with obesity and depression were less likely to receive OFA (OR = 0.80, 95% CI [0.67, 0.95]; p = .010 OR = 0.85, 95% CI [0.73, 0.98]; p = .030, respectively). CONCLUSIONS: Use of post-surgical OFA was limited overall and was not favored in some patient groups prone to ORADEs, indicating missed opportunities to reduce opioid use and ORADE incidence. A substantial proportion of OFA patients was contributed by a few hospitals with especially high rates of OFA, suggesting that hospital policies, institutional structure and cross-functional departmental commitment to reducing opioid use may play a large role in the implementation of OFA.


Assuntos
Dor Aguda/tratamento farmacológico , Analgésicos não Narcóticos/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Adolescente , Adulto , Idoso , Analgésicos Opioides/administração & dosagem , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Estados Unidos , Adulto Jovem
7.
Clin Drug Investig ; 38(3): 259-268, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29214506

RESUMO

BACKGROUND AND OBJECTIVE: Several features favor paracetamol (acetaminophen) administration by the intravenous rather than the oral route in the postoperative setting. This study compared the pharmacokinetics and bioavailability of oral and intravenous paracetamol when given with or without an opioid, morphine. METHODS: In this randomized, single-blind, parallel, repeat-dose study in healthy adults, subjects received four repeat doses of oral or intravenous 1000 mg paracetamol at 6-h intervals, and morphine infusions (0.125 mg/kg) at the 2nd and 3rd intervals. Comparisons of plasma pharmacokinetic profiles were conducted before, during, and after opioid co-administrations. RESULTS: Twenty-two subjects were included in the pharmacokinetic analysis. Observed paracetamol peak concentration (C max) and area under the plasma concentration-time curve over the dosing interval (AUC0-6) were reduced when oral paracetamol was co-administered with morphine (reduced from 11.6 to 7.25 µg/mL and from 31.00 to 25.51 µg·h/mL, respectively), followed by an abruptly increased C max and AUC0-6 upon discontinuation of morphine (to 13.5 µg/mL and 52.38 µg·h/mL, respectively). There was also a significantly prolonged mean time to peak plasma concentration (T max) after the 4th dose of oral paracetamol (2.84 h) compared to the 1st dose (1.48 h). However, pharmacokinetic parameters of paracetamol were not impacted when intravenous paracetamol was co-administered with morphine. CONCLUSIONS: Morphine co-administration significantly impacted the pharmacokinetics of oral but not intravenous paracetamol. The abrupt release of accumulated paracetamol at the end of morphine-mediated gastrointestinal inhibition following oral but not intravenous administration of paracetamol suggests that intravenous paracetamol provides a better option for the management of postoperative pain. CLINICALTRIALS. GOV IDENTIFIER: NCT02848729.


Assuntos
Acetaminofen/farmacocinética , Analgésicos não Narcóticos/farmacocinética , Analgésicos Opioides/farmacocinética , Morfina/farmacocinética , Acetaminofen/administração & dosagem , Administração Intravenosa , Administração Oral , Adulto , Analgésicos não Narcóticos/administração & dosagem , Analgésicos Opioides/administração & dosagem , Disponibilidade Biológica , Interações Medicamentosas/fisiologia , Quimioterapia Combinada , Feminino , Voluntários Saudáveis , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Método Simples-Cego , Adulto Jovem
8.
J Clin Med Res ; 10(6): 499-507, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29707092

RESUMO

BACKGROUND: Post-surgical pain impacts many patient outcomes. Effective pain management increasingly relies on multimodal analgesia regimens in which acetaminophen (APAP) is a key component. The aim of our study was to examine the impact of oral APAP versus intravenous (IV) APAP as a component of post-surgical pain management after Cesarean sections and hysterectomies. METHODS: A retrospective analysis of the Cerner HealthFacts® database (from January, 2011 to December, 2015) was conducted to compare outcomes of Cesarean section and hysterectomy surgery patients who received oral APAP to those who received IV APAP post-surgically. Length of stay (LOS), daily morphine milligram equivalent (MME) consumption, the presence of potential opioid-related adverse events (ORADEs), and total pharmacy costs were assessed. Adjusted results were derived using inverse probability weighted regression adjustment (IPW-RA) estimators based on covariates that included demographics, comorbidities, patient clinical characteristics, and hospital characteristics. RESULTS: The study identified 29,124 Cesarean section patients (24,612 oral APAP; 4,512 IV APAP) and 9,767 hysterectomy surgery patients (5,586 oral APAP; 4,181 IV APAP). Compared to the oral APAP group, the IV APAP group had reductions in adjusted LOS (Cesarean section: -11.7% days (P < 0.001), hysterectomy: -11.8% days (P = 0.005)), lowered adjusted daily MME consumption from day 0 to day 3 (Cesarean section: -1.6 mg (P < 0.001), hysterectomy: -1.7 mg (P = 0.014)), and reduced risk of ORADEs for Cesarean sections (relative risk of 0.45, P < 0.001). Total pharmacy costs were not significantly different between the two APAP groups. CONCLUSIONS: Post-surgical pain managed with IV APAP in patients undergoing Cesarean section or hysterectomy was associated with shorter LOS, reduced risk of ORADEs, and lower opioid consumption compared to patients managed with oral APAP, without adversely impacting total pharmacy costs.

9.
Obesity (Silver Spring) ; 25(5): 842-849, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28345809

RESUMO

OBJECTIVE: Lorcaserin, a 5-HT2C receptor agonist approved for chronic weight management, is also associated with improvements in glycemic parameters in patients with/without type 2 diabetes mellitus (T2DM), but the extent to which these effects are mediated by weight loss is unknown. This post hoc analysis further examines glycemic data from the Phase III BLOOM-DM study stratified by weight changes. METHODS: Patients with T2DM were randomized to lorcaserin 10 mg twice daily or placebo. Glycemic parameters were reported by Week (W) 12 weight loss status ≥5% (Group ≥5%) or <5% (Group <5%). Glycemic parameter changes were analyzed using ANCOVA; the relationship between glycemic parameter changes and percent weight loss was assessed by simple regression modeling. RESULTS: Group ≥5% receiving lorcaserin had greater improvements in fasting plasma glucose (FPG) at W2 (prior to significant weight loss) and greater improvements in glycated hemoglobin (HbA1c) at W12 versus placebo. These improvements were maintained through W52 (FPG, -29.3 mg/dL vs. -24.2 mg/dL; HbA1c, -1.2% vs. -1.1%). Group <5% treated with lorcaserin also had larger decreases in FPG (-28.3 mg/dL vs. -10.0 mg/dL) and HbA1c (-0.8% vs. -0.4%) at W52 versus placebo despite limited weight loss. CONCLUSIONS: Lorcaserin may have beneficial effects on glycemic control with or without weight loss.


Assuntos
Benzazepinas/uso terapêutico , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas/efeitos dos fármacos , Adolescente , Adulto , Idoso , Benzazepinas/administração & dosagem , Benzazepinas/farmacologia , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Feminino , Hemoglobinas Glicadas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
10.
Obesity (Silver Spring) ; 25(1): 39-44, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27888609

RESUMO

OBJECTIVE: To evaluate the effects of lorcaserin in patients with pre-existing Food and Drug Administration (FDA)-defined valvulopathy. METHODS: This is a pooled, post hoc analysis of three Phase 3 studies. BLOOM and BLOSSOM patients were 18 to 65 years of age without diabetes and with a body mass index (BMI) of 27 to 29.9 kg/m2 and ≥1 weight-related comorbidity or a BMI of 30 to 45 kg/m2 . BLOOM-DM patients had a BMI of 27 to 45 kg/m2 and type 2 diabetes. Patients were treated with placebo, lorcaserin 10 mg once daily, or lorcaserin 10 mg twice daily. Serial echocardiographs were obtained at baseline and every 6 months. RESULTS: Included patients (N = 169) had FDA-defined valvulopathy at baseline and a week 52 echocardiogram. At week 52, 35.5% and 52.7% of patients experienced changes from baseline in aortic and mitral regurgitation, respectively. Numerically greater proportions of patients taking lorcaserin versus placebo had decreases in aortic (33.0% vs. 28.3%) or mitral (41.3% vs. 36.7%) regurgitation. Fewer patients taking lorcaserin versus placebo had increases in aortic (2.8% vs. 6.7%) or mitral (8.3% vs. 21.7%) regurgitation. No adverse event-related discontinuation was due to a valve problem. CONCLUSIONS: These data suggest that lorcaserin does not adversely affect valvular disease in patients with pre-existing FDA-defined valvulopathy.


Assuntos
Fármacos Antiobesidade/administração & dosagem , Insuficiência da Valva Aórtica/tratamento farmacológico , Benzazepinas/administração & dosagem , Diabetes Mellitus Tipo 2/tratamento farmacológico , Adulto , Idoso , Insuficiência da Valva Aórtica/complicações , Índice de Massa Corporal , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Redução de Peso/efeitos dos fármacos
11.
Obesity (Silver Spring) ; 25(5): 857-865, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28440045

RESUMO

OBJECTIVE: To assess the short-term tolerability of lorcaserin alone or with two dose regimens of phentermine. METHODS: This was a 12-week, randomized, double-blind, pilot safety study of N = 238 nondiabetic patients with obesity or overweight with ≥1 comorbidity randomized to lorcaserin 10 mg twice daily (BID; LOR BID) alone or with phentermine 15 mg once daily (QD; LOR BID+PHEN QD) or 15 mg twice daily (LOR BID+PHEN BID). Patients reporting ≥ 1 of 9 potentially serotonergic adverse events (AEs), mean weight loss (WL), and ≥5% WL are reported. RESULTS: N = 238 were randomized, and N = 235 were treated. N = 94 reported potentially serotonergic AEs: 37.2% LOR BID, 42.3% LOR BID+PHEN QD, and 40.5% LOR BID+PHEN BID. AEs leading to discontinuation were reported approximately twice as often in the LOR BID+PHEN BID group versus the LOR BID group. Mean WL was 3.5 kg/3.3%, 7.0 kg/6.7%, and 7.6 kg/7.2% for LOR BID, LOR BID+PHEN QD, and LOR BID+PHEN BID, respectively. At least 5% WL was achieved by 28.2% LOR BID, 59.0% LOR BID+PHEN QD (P = 0.0002 vs. LOR BID), and 70.9% LOR BID+PHEN BID (P < 0.0001 vs. LOR BID) patients. CONCLUSIONS: Phentermine added to lorcaserin enhanced short-term weight loss but did not increase incidence of potentially serotonergic AEs; however, phentermine twice daily increased discontinuation compared to both lorcaserin alone and lorcaserin plus phentermine once daily.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Benzazepinas/uso terapêutico , Fentermina/uso terapêutico , Redução de Peso/efeitos dos fármacos , Adolescente , Adulto , Fármacos Antiobesidade/administração & dosagem , Fármacos Antiobesidade/farmacologia , Benzazepinas/administração & dosagem , Benzazepinas/farmacologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fentermina/administração & dosagem , Fentermina/farmacologia , Projetos Piloto , Adulto Jovem
12.
Clin Ther ; 38(6): 1498-1509, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27206567

RESUMO

PURPOSE: Lorcaserin is a selective serotonin 2C receptor (5-HT2C) agonist approved in the United States for use in chronic weight management as an adjunct to a reduced-calorie diet and increased physical activity. Its pharmacologic activity is limited to 5-HT subtype 2 receptors. The potency of lorcaserin for the 5-HT2C receptor is 14-fold greater than its potency for the 5-HT2A receptor and 61-fold greater than its potency for the 5-HT2B receptor. Although 5-HT receptors have been implicated in serotonin syndrome, the precise pathogenesis is unknown. Given a theoretic risk for this syndrome in patients administered lorcaserin either alone or in combination with certain serotonergic agents (eg, selective serotonin reuptake inhibitors [SSRIs] and serotonin-norepinephrine reuptake inhibitors [SNRIs]), patients taking prohibited serotonergic agents were excluded from the Phase III clinical trials. This retrospective analysis evaluated the tolerability of lorcaserin in patients who took protocol-allowed or proscribed serotonergic agents for varying durations of up to 1 year during the BLOOM, BLOSSOM, and BLOOM-DM studies. METHODS: Patients randomly assigned to receive either lorcaserin 10 mg QD, lorcaserin 10 mg BID, or placebo and who took a spectrum of serotonergic agents were evaluated at week 52 of treatment (814 and 624 patients receiving lorcaserin and placebo, respectively, were found to have taken allowed or prohibited serotonergic agents during these trials). After the use of a proscribed serotonergic agent was discovered, these patients were discontinued from the trial and followed. FINDINGS: None of the patients in the serotonergic agent subpopulation or in the overall safety population met the clinical criteria of serotonin syndrome. The proportions of patients experiencing any adverse event (AE) were balanced in the lorcaserin and placebo groups in the prohibited serotonergic agent subpopulation. The prevalences of the most common AEs were similar between the serotonergic agent subpopulation and the overall safety population. IMPLICATIONS: The concurrent use of lorcaserin and prohibited or allowed serotonergic agents did not appear to have increased the spectrum or intensity of AEs potentially associated with serotonin excess in this limited dataset. However, the sample population was too small to rule out an effect on a rare event such as serotonin syndrome. ClinicalTrials.gov identifiers: NCT00395135, NCT00603902, and NCT00603291.


Assuntos
Fármacos Antiobesidade/efeitos adversos , Benzazepinas/efeitos adversos , Sobrepeso/tratamento farmacológico , Receptor 5-HT2C de Serotonina/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/uso terapêutico , Serotoninérgicos/efeitos adversos , Síndrome da Serotonina/induzido quimicamente , Adulto , Interações Medicamentosas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/tratamento farmacológico , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Estudos Retrospectivos , Redução de Peso
13.
Postgrad Med ; 128(4): 364-70, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27116910

RESUMO

OBJECTIVES: Lorcaserin is a selective 5-HT2C (5-hydroxytryptamine 2C) receptor agonist indicated for weight management. Here, we assess the impact of lorcaserin on progression from prediabetes to type 2 diabetes (T2D) and on reversion from prediabetes to euglycemia. METHODS: This is a post hoc analysis of pooled data from two Phase 3 studies, BLOOM and BLOSSOM (N = 6136), evaluating the impact of lorcaserin on weight and glycemic parameters over 52 weeks in the subpopulation of obese/overweight subjects with prediabetes, alternately defined by fasting plasma glucose (FPG) 100-125 mg/dl or glycated hemoglobin (HbA1c) 5.7-6.4% at baseline. RESULTS: At Week 52, in the subpopulation with prediabetes, nearly twice as many lorcaserin-treated subjects achieved ≥5% weight loss versus placebo (HbA1c: 55.6% vs. 27.5%, p < 0.001; FPG: 52.8% vs. 28.8%, p < 0.001), and a significantly lower percentage of lorcaserin-treated subjects progressed to T2D versus placebo based on HbA1c (lorcaserin 3.2%, placebo 5.0%, p = 0.032) but not FPG (lorcaserin 1.6%, placebo 2.6%, p = 0.227). A significantly greater proportion of lorcaserin-treated subjects versus placebo also reverted to euglycemia based on both HbA1c (lorcaserin 40%, placebo 29.5%, p < 0.001) and FPG (lorcaserin 52.4%, placebo 46.5%, p = 0.047). CONCLUSION: In subjects with prediabetes, lorcaserin may contribute to weight loss and improve glycemic parameters, and thus may help with preventing progression to T2D and promoting reversion to euglycemia. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifiers are NCT00395135 (BLOOM) and NCT00603902 (BLOSSOM).


Assuntos
Benzazepinas/uso terapêutico , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/prevenção & controle , Hemoglobinas Glicadas/metabolismo , Estado Pré-Diabético/tratamento farmacológico , Agonistas do Receptor 5-HT2 de Serotonina/uso terapêutico , Adulto , Ensaios Clínicos Fase III como Assunto , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Estado Pré-Diabético/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Postgrad Med ; 128(6): 591-7, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27389084

RESUMO

OBJECTIVES: Treatment guidelines for type 2 diabetes mellitus (T2DM) suggest weight loss as a means to maintain glycemic control. Lorcaserin has been approved for chronic weight management in the United States as an adjunct to a reduced-calorie diet and exercise, and the previous phase 3 Behavioral Modification and Lorcaserin for Obesity and Overweight Management in Diabetes Mellitus (BLOOM-DM) study has shown that, in addition to weight loss, lorcaserin is associated with improvements in glycemic parameters. In this post hoc analysis of the BLOOM-DM trial, the relationship between responder status (patients achieving ≥5% weight loss at Week 52) and glycemic and cardiometabolic parameters is evaluated. METHODS: Data are presented for patients receiving lorcaserin 10 mg twice daily or placebo for 52 weeks. RESULTS: More than twice as many patients receiving lorcaserin plus diet and exercise counseling were classified as Week 52 responders compared to those receiving diet and exercise counseling alone (37.5% vs. 16.1%, respectively; p < 0.001), and lorcaserin Week 52 responders had greater improvements vs. placebo Week 52 responders in FPG (-38.1 mg/dL vs. -26.0 mg/dL) and HbA1c (-1.3% vs. -1.0%). Furthermore, more lorcaserin-treated Week 52 responders decreased the number of concomitant oral antidiabetic medications (OADs) used, and fewer increased the number of OADs used, compared to placebo. Unexpectedly, lorcaserin Week 52 nonresponders also had substantial reductions in glycemic levels, despite very modest weight loss. CONCLUSIONS: These data support lorcaserin use in overweight and obese patients with T2DM to promote weight loss and facilitate glycemic control. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifier is NCT00603291.


Assuntos
Benzazepinas/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Sobrepeso/tratamento farmacológico , Agonistas do Receptor de Serotonina/uso terapêutico , Adolescente , Adulto , Idoso , Glicemia , Índice de Massa Corporal , Aconselhamento , Dieta , Método Duplo-Cego , Exercício Físico , Feminino , Hemoglobinas Glicadas , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obesidade/terapia , Sobrepeso/terapia , Grupos Raciais , Redução de Peso/efeitos dos fármacos , Adulto Jovem
15.
Postgrad Med ; 128(8): 740-746, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27659698

RESUMO

OBJECTIVES: Lorcaserin is a serotonin 2C receptor agonist approved for chronic weight management. This analysis explores the number of patients needed to be treated (NNT) with lorcaserin for one more patient to achieve weight loss and glycemic goals. METHODS: This is a post hoc analysis of three Phase 3 studies in adults with and without type 2 diabetes mellitus (T2DM) treated with lorcaserin 10 mg BID or placebo. NNT is reported for patients achieving ≥5% or ≥10% weight loss, achievement of either HbA1c <5.7% or FPG <100 mg/dL in patients with prediabetes, and reduction of HbA1c to <7% in patients with T2DM at Week 52. RESULTS: In the modified intention-to-treat (MITT) population, NNTs for ≥5% and ≥10% weight loss were 3.6 and 6.2 (without T2DM) and 4.3 and 7.5 (with T2DM); in Week 12 responders (≥5% weight loss at Week 12), NNTs were 1.7 and 2.6 (without T2DM) and 1.9 and 3.2 (with T2DM). In patients with prediabetes, NNTs to achieve HbA1c <5.7% were 9.9 (MITT) and 5.2 (Week 12 responders). In patients with T2DM, NNTs to achieve HbA1c <7% were 4.2 (MITT) and 2.3 (Week 12 responders). CONCLUSION: In addition to weight management, lorcaserin improved glycemic control in patients with prediabetes and facilitated targeted HbA1c reduction in patients with T2DM, especially for those who achieved ≥5% weight loss by Week 12. Assessment of treatment response at Week 12 is a valuable tool to achieve efficient use of healthcare resources. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifiers are NCT00395135, NCT00603291, and NCT00603902.


Assuntos
Benzazepinas/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Obesidade/tratamento farmacológico , Estado Pré-Diabético/tratamento farmacológico , Agonistas do Receptor 5-HT2 de Serotonina/uso terapêutico , Adolescente , Adulto , Idoso , Benzazepinas/administração & dosagem , Glicemia/efeitos dos fármacos , Índice de Massa Corporal , Peso Corporal/efeitos dos fármacos , Comorbidade , Método Duplo-Cego , Quimioterapia Combinada , Exercício Físico , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Masculino , Pessoa de Meia-Idade , Agonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Redução de Peso/efeitos dos fármacos , Adulto Jovem
16.
Epilepsy Res ; 119: 34-40, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26656783

RESUMO

Perampanel is a selective, noncompetitive AMPA receptor antagonist with demonstrated efficacy and tolerability in partial seizures in patients aged ≥ 12 years in Phase III studies. Post-hoc analysis of these studies was conducted to determine the efficacy and tolerability of perampanel based on the number of concomitant antiepileptic drugs (AEDs) at baseline, as well as to examine which baseline characteristics, if any, were predictors of efficacy. Efficacy parameters were based on the number of baseline AEDs, and logistic regression analyses were used to evaluate the association of demographic and baseline clinical factors with probability of ≥ 50% reduction in seizure frequency. Patients on 1 AED at baseline were significantly more likely to have reduced seizure frequency (P<0.02) and improved 50% responder rate (P<0.02) than patients on 3 AEDs at baseline. Secondarily generalized seizures at baseline, unknown etiology, and use of concomitant non-inducer AEDs were also established as positive predictors of efficacy (50% responder rate; P<0.01). Patients with more AEDs at baseline were associated with greater use of inducers (P<0.01), which may result in decreased exposure of perampanel in these patients and lower efficacy. Patients with 1 AED at baseline had a significantly shorter time since diagnosis compared with patients in the 3 (P<0.01) AEDs group, as well as a lower median seizure frequency at baseline compared to patients on 3 AEDs (P<0.05), suggesting that the reduced efficacy of perampanel with 3 AEDs may also be associated with the greater severity of seizures in the patient groups. The incidence of adverse events in perampanel-treated patients was similar regardless of the number of AEDs at baseline. Greater efficacy is predicted for patients receiving fewer concomitant AEDs when starting perampanel, as well as for those receiving concomitant treatment with AEDs that are not CYP3A4 enzyme-inducers, compared to patients treated with multiple concomitant AEDs. The results of this study provide additional information for clinicians considering adding perampanel to their patients' treatment regimen earlier rather than later, and offer evidence regarding the potential for increased efficacy with a decreased medication burden.


Assuntos
Anticonvulsivantes/administração & dosagem , Epilepsia/tratamento farmacológico , Piridonas/administração & dosagem , Adulto , Anticonvulsivantes/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Nitrilas , Medicina de Precisão , Piridonas/efeitos adversos , Convulsões/tratamento farmacológico , Índice de Gravidade de Doença , Resultado do Tratamento
17.
Epilepsy Res ; 114: 131-40, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26088896

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of perampanel in patients with drug-resistant partial seizures after the conversion from double-blind placebo in three phase III studies to open-label perampanel, and to assess the impact of perampanel titration rates through a comparison of weekly vs biweekly dose increases. METHODS: Patients who completed the three multinational, double-blind, placebo-controlled, phase III core studies (studies 304, 305, or 306) were eligible to enroll in the extension study (study 307). Patients completing the double-blind treatment (6-week titration, 13-week maintenance) with placebo (DB-PBO) or perampanel (DB-PER) began the extension study with a 16-week blinded conversion period, during which DB-PBO patients were switched to perampanel. Doses were titrated in 2-mg increments (biweekly) to an individualized maximum tolerated dose of perampanel (up to 12 mg/day). Patients then entered a planned, open-label treatment period. RESULTS: Perampanel treatment during the extension study reduced total seizure frequency/28 days relative to the double-blind prerandomization baseline regardless of prior perampanel or placebo treatment in the core studies. In the DB-PBO patients, median percent reductions in seizure frequency at the end of the double-blind period, at the end of the conversion period, and at Weeks 40-52 in the open-label maintenance period were 18.6%, 44.3%, and 55.0%, respectively. Seizure control was also improved in the DB-PER patients during the extension period compared to the end of the double-blind period. Responder rates were similar between the 2 patient groups at the end of the conversion period. Perampanel was well tolerated, with the most common treatment-emergent adverse events being dizziness, somnolence, weight increase, irritability, fatigue, and headache. For those patients randomized to the 12 mg group (DB-PER 12 mg), 78.4% reached the daily dose of 10 or 12 mg by the end of the 6-week titration period of the double-blind phase. By the end of the 16-week conversion period of the extension study, 64.0% of DB-PBO patients reached the daily dose of 10 or 12 mg. Seizure frequency reduction was greater after the first 13-week maintenance period of the extension study in the DB-PBO group compared to patients assigned to DB-PER 12mg during the 13-week maintenance period of the double-blind study. CONCLUSION: Patients who received placebo in the phase III core DB studies and transitioned to perampanel in the open-label extension study (DB-PBO) achieved seizure control at the end of the conversion period similar to that of patients who had been previously exposed to perampanel (DB-PER) as well as comparable safety outcomes. Patients who received perampanel during the core studies and continued with treatment during the extension study (DB-PER) also showed sustained improvements in seizure control with long-term exposure to perampanel.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsias Parciais/tratamento farmacológico , Piridonas/uso terapêutico , Adolescente , Adulto , Idoso , Anticonvulsivantes/efeitos adversos , Criança , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Nitrilas , Piridonas/efeitos adversos , Convulsões/prevenção & controle , Resultado do Tratamento , Adulto Jovem
18.
Neurology ; 84(19): 1972-80, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25878177

RESUMO

OBJECTIVE: Evaluate the impact of concomitant enzyme (CYP3A4)-inducer antiepileptic drugs (EIAEDs) on the efficacy and safety of perampanel in patients from the 3 phase-III clinical trials. METHODS: Patients with pharmacoresistant partial-onset seizures in the 3 phase-III clinical studies were aged 12 years and older and receiving 1 to 3 concomitant antiepileptic drugs. Following 6-week baseline, patients were randomized to once-daily, double-blind treatment with placebo or perampanel 8 or 12 mg (studies 304 and 305) or placebo or perampanel 2, 4, or 8 mg (study 306). RESULTS: Treatment response assessed by median percent reduction in seizure frequency and responder rates improved with perampanel compared with placebo. However, at 8 and 12 mg, the treatment response was significantly greater in patients receiving non-EIAEDs. The treatment effect (perampanel-placebo) also demonstrated a dose-dependent increase in all patients. The overall incidence of treatment-emergent adverse events was similar regardless of the presence of EIAEDs. Occurrence of some adverse events, such as fatigue, somnolence, dizziness, irritability, was greater in patients receiving non-EIAEDs, as was discontinuation because of adverse events. CONCLUSIONS: Perampanel shows efficacy and safety in the presence and absence of EIAEDs. As systemic exposure to perampanel increases, so does efficacy. Given the extensive metabolism of perampanel, systemic exposure is clearly reduced with concomitant administration of CYP3A4 inducers. This supports the strategy of dosing perampanel to clinical effect. Recognition of these pharmacokinetic interactions will be important in the optimization of this novel medication. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that 2 to 12 mg/d doses of perampanel reduced seizure frequency and improved responder rate in the presence and absence of EIAEDs.


Assuntos
Anticonvulsivantes/administração & dosagem , Indutores do Citocromo P-450 CYP3A/administração & dosagem , Epilepsia/tratamento farmacológico , Piridonas/administração & dosagem , Adulto , Anticonvulsivantes/efeitos adversos , Indutores do Citocromo P-450 CYP3A/efeitos adversos , Distúrbios do Sono por Sonolência Excessiva/induzido quimicamente , Distúrbios do Sono por Sonolência Excessiva/diagnóstico , Tontura/induzido quimicamente , Tontura/diagnóstico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Combinação de Medicamentos , Interações Medicamentosas , Epilepsia/complicações , Epilepsia/diagnóstico , Fadiga/induzido quimicamente , Fadiga/diagnóstico , Feminino , Humanos , Internacionalidade , Masculino , Transtornos Mentais/induzido quimicamente , Transtornos Mentais/diagnóstico , Nitrilas , Piridonas/efeitos adversos , Resultado do Tratamento
19.
Eur J Paediatr Neurol ; 19(4): 435-45, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25823975

RESUMO

OBJECTIVE: Assess perampanel's efficacy and safety as adjunctive therapy in adolescents (ages 12-17) with drug-resistant partial seizures. METHODS: Adolescent patients enrolled in multinational, double-blind, placebo-controlled, phase III core studies (studies 304, 305, or 306) completed 19-week, double-blind phase (6-week titration/13-week maintenance) with once-daily perampanel or placebo. Upon completion, patients were eligible for the extension (study 307), beginning with 16-week, blinded conversion, during which placebo patients switched to perampanel. Patients then entered the open-label treatment. RESULTS: Of 1480 patients from the core studies, 143 were adolescents. Pooled adolescent data from these core studies demonstrated median percent decreases in seizure frequency for perampanel 8 mg (34.8%) and 12 mg (35.6%) were approximately twice that of placebo (18.0%). Responder rates increased with perampanel 8 mg (40.9%) and 12 mg (45.0%) versus placebo (22.2%). Adolescents receiving concomitant enzyme-inducing antiepileptic drugs (AEDs) had smaller reductions in seizure frequency (8 mg:31.6%; 12 mg:26.8%) than those taking non-inducing AEDs (8 mg:54.6%; 12 mg:52.7%). Relative to pre-perampanel baseline, seizure frequency and responder rates during the extension (Weeks 1-52) improved with perampanel. Most commonly reported adverse events in adolescents during the core studies were dizziness (20.4%), somnolence (15.3%), aggression (8.2%), decreased appetite (6.1%), and rhinitis (5.1%). Dizziness (13.2%), somnolence (11.6%), and aggression (6.6%) most often led to perampanel interruption/dose adjustment during the extension. SIGNIFICANCE: Data demonstrated adjunctive perampanel treatment in adolescents with drug-resistant partial seizures produced better seizure control versus placebo, sustained seizure frequency improvements, and a generally favorable safety profile. Results were comparable to the overall study population. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov Identifiers: Study 304: NCT00699972; 305: NCT00699582; 306: NCT00700310; Study 307: NCT00735397.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Piridonas/uso terapêutico , Adolescente , Método Duplo-Cego , Quimioterapia Combinada , Epilepsias Parciais/tratamento farmacológico , Feminino , Humanos , Masculino , Nitrilas , Convulsões/tratamento farmacológico , Resultado do Tratamento
20.
J Appl Physiol (1985) ; 93(6): 2023-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12391054

RESUMO

We assessed the effects of naloxone, an opioid antagonist, on exercise capacity in 13 men and 5 women (mean age = 30.1 yr, range = 21-35 yr) during a 25 W/min incremental cycle ergometer test to exhaustion on different days during familiarization trial and then after 30 mg (iv bolus) of naloxone or placebo (Pl) in a double-blind, crossover design. Minute ventilation (Ve), O(2) consumption (Vo(2)), CO(2) production, and heart rate (HR) were monitored. Perceived exertion rating (0-10 scale) and venous samples for lactate were obtained each minute. Lactate and ventilatory thresholds were derived from lactate and gas-exchange data. Blood pressure was obtained before exercise, 5 min postinfusion, at maximum exercise, and 5 min postexercise. There were no control-Pl differences. The naloxone trial demonstrated decreased exercise time (96% Pl; P < 0.01), total cumulative work (96% Pl; P < 0.002), peak Vo(2) (94% Pl; P < 0.02), and HR (96% Pl; P < 0.01). Other variables were unchanged. HR and Ve were the same at the final common workload, but perceived exertion was higher (8.1 +/- 0.5 vs. 7.1 +/- 0.5) after naloxone than Pl (P < 0.01). The threshold for effort perception amplification occurred at approximately 60 +/- 4% of Pl peak Vo(2). Thus we conclude that peak work capacity was limited by perceived exertion, which can be attenuated by endogenous opioids rather than by physiological limits.


Assuntos
Naloxona/administração & dosagem , Antagonistas de Entorpecentes/administração & dosagem , Consumo de Oxigênio/efeitos dos fármacos , Percepção/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Adulto , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Teste de Esforço , Fadiga/metabolismo , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Ácido Láctico/metabolismo , Masculino , Peptídeos Opioides/metabolismo , Esportes
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