RESUMEN
BACKGROUND: Dual anti-platelet therapy with clopidogrel and low-dose aspirin increases the risk for gastrointestinal clinical events. Omeprazole has been shown to significantly reduce these events without compromising cardiovascular safety in patients treated with dual anti-platelet therapy. Whether or not omeprazole improves patient-reported outcomes is undetermined. AIM: To assess the impact of prophylactic omeprazole with background dual anti-platelet therapy on patient-reported symptoms of dyspepsia compared to placebo. METHODS: We analysed results of the Severity of Dyspepsia Assessment questionnaires collected in the Clopidogrel and the Optimization of Gastrointestinal Events Trial. RESULTS: Patient-reported outcome data from 3759 subjects were available for analysis. At 4 weeks, the mean scores of pain intensity and nonpain symptoms were lower in the omeprazole group (5.61 ± 0.17 vs. 6.40 ± 0.17, P = 0.001, and 10.61 ± 0.07 vs. 11.00 ± 0.07, P < 0.001 respectively). These differences were maintained at 24 weeks (5.91 ± 0.35 vs. 7.10 ± 0.37, P = 0.020 for pain intensity; 10.36 ± 0.12 vs. 10.93 ± 0.13, P = 0.001 for nonpain symptoms). After adjusting for covariates there were no statistically significant differences between the groups in the percent of patients with dyspepsia during follow-up. CONCLUSIONS: In addition to reducing the risk of gastrointestinal bleeding, statistically significant benefits with prophylactic omeprazole use on both pain and nonpain symptoms were evident at 4 weeks and sustained through 24 weeks. The clinical significance of these overall results is unclear, but greater in patients with pain at baseline.
Asunto(s)
Aspirina/efectos adversos , Dispepsia/tratamiento farmacológico , Inhibidores de la Bomba de Protones/uso terapéutico , Ticlopidina/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Aspirina/uso terapéutico , Plaquetas , Clopidogrel , Método Doble Ciego , Quimioterapia Combinada , Femenino , Hemorragia Gastrointestinal/inducido químicamente , Humanos , Masculino , Persona de Mediana Edad , Omeprazol/uso terapéutico , Inhibidores de Agregación Plaquetaria/efectos adversos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Ticlopidina/efectos adversos , Ticlopidina/uso terapéutico , Adulto JovenRESUMEN
OBJECTIVE: Gastrointestinal (GI) symptoms are common in patients taking nonselective, nonsteroidal anti-inflammatory drugs (nsNSAIDs) and are often a reason for therapy discontinuation. In osteoarthritis (OA) and rheumatoid arthritis (RA) patients requiring pain control, selective COX-2 NSAID use is typically associated with less dyspepsia than is nsNSAID use. Little is known about NSAID tolerance in patients with gastroesophageal reflux disease (GERD). This study assessed nsNSAID and celecoxib prescription patterns, in particular persistence, in OA/RA patients with concomitant diagnosis of GERD. METHODS: An observational study of GERD patients with a diagnosis of OA/RA using two separate databases, the IMS Lifelink Health Plan Claims Database (PharMetrics) and Market Scan Claims Database (Medstat) was conducted. In each database, parallel and separate analyses were performed in adult patients who had their first GERD diagnosis in 2006 and who were subsequently diagnosed with OA or RA in the same year. From this subset of patients, celecoxib-naïve and nsNSAID-naïve cohorts were identified and patients were selected. Patients with pre-existing GI conditions were excluded from the study. Persistence, measured as time to discontinuation, was evaluated by Kaplan-Meier survival curves and Cox proportional hazards models. Reasons for discontinuations were not available in these databases. RESULTS: Fewer patients discontinued celecoxib as compared to nsNSAIDs during the 60 days of the first prescription and throughout the entire follow-up period. After adjusting for baseline characteristics, celecoxib patients still had significantly decreased risk of discontinuation as compared to nsNSAID patients (p < 0.0001). Replication of these observations in two separate, large patient databases increases the confidence in this study's conclusion. LIMITATIONS: Limitations include those inherent to claims data analyses and retrospective review, e.g. these data do not provide clinical information related to reasons for medication discontinuation. CONCLUSION: In patients with concomitant GERD and OA or RA who require anti-inflammatory treatment, significantly more patients treated with celecoxib were persistent with their treatment than were patients treated with nsNSAIDs.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Artritis Reumatoide/complicaciones , Artritis Reumatoide/tratamiento farmacológico , Reflujo Gastroesofágico/complicaciones , Cumplimiento de la Medicación/estadística & datos numéricos , Osteoartritis/complicaciones , Osteoartritis/tratamiento farmacológico , Pirazoles/uso terapéutico , Sulfonamidas/uso terapéutico , Adulto , Anciano , Algoritmos , Artritis Reumatoide/epidemiología , Celecoxib , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Bases de Datos como Asunto , Femenino , Reflujo Gastroesofágico/tratamiento farmacológico , Reflujo Gastroesofágico/epidemiología , Humanos , Revisión de Utilización de Seguros , Masculino , Persona de Mediana Edad , Osteoartritis/epidemiologíaRESUMEN
BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAID)-related GI effects vary based on patient characteristics. AIMS: To assess risk factors for NSAID-associated upper GI clinical events and dyspepsia. METHODS: Patients ≥50 years with osteoarthritis or rheumatoid arthritis were randomized to etoricoxib or diclofenac in a prespecified intent-to-treat analysis of three double-blind randomized trials. Potential risk factors for upper GI clinical events (bleeding, perforation, obstruction, or ulcer), complicated events (perforation, obstruction, bleeding) and discontinuations due to dyspepsia were assessed with Cox proportional hazard models. RESULTS: Significant predictors of clinical events and complicated events included age ≥65 years [hazards ratios (HRs) = 2.25 (1.84-2.76), 4.09 (2.82-5.92)], prior event [HRs = 2.57 (1.94-3.39), 3.23 (2.09-5.00)], low-dose aspirin [HRs = 2.34 (1.87-2.92), 3.41 (2.33-5.00)] and corticosteroid [HRs = 1.85 (1.41-2.43), 2.09 (1.29-3.38)]. Predictors of discontinuation due to dyspepsia included prior dyspepsia [HR = 1.78 (1.44-2.00)], prior event [HR = 1.78 (1.40-2.27)] and age ≥65 years [HR = 1.35 (1.16-1.57)]. CONCLUSIONS: Assessment for age ≥65 years, prior upper GI clinical events and low-dose aspirin use are key in identifying patients who should either avoid NSAIDs or employ management strategies to reduce NSAID-associated upper GI events. Prior dyspepsia or upper GI clinical events and age ≥65 years also predict an increased risk of developing dyspepsia severe enough to necessitate discontinuation of NSAIDs.
Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Artritis/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa 2/efectos adversos , Diclofenaco/efectos adversos , Enfermedades Gastrointestinales/inducido químicamente , Piridinas/efectos adversos , Sulfonas/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Etoricoxib , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo , Tracto Gastrointestinal Superior/efectos de los fármacosRESUMEN
OBJECTIVE: To assess 12-month healthcare resource utilization and costs associated with upper gastrointestinal (UGI) bleeding events. METHODS: Patients hospitalized with a UGI bleeding event were identified in US national health-plan claims data (1999-2003) and propensity matched to control patients without UGI bleeding in the same health plan. Matching criteria included age, gender, index date, Charlson Comorbidity Index score, geographic region, and prior medical utilization. RESULTS: A total of 9,033 UGI-bleed patients and 579,018 control patients met the inclusion criteria, yielding 4,651 matched pairs. After matching, differences between the UGI bleed and general population cohorts remained for office visits, ER visits, and ER costs during the 6-month baseline period prior to the index date. During the 12 months following the index date, both UGI-related healthcare utilization and total healthcare, medical, and pharmacy costs incurred by the UGI-bleed cohort were significantly greater (p< 0.0001) than those incurred by the general population cohort (mean of $20,405 vs. 3,652), even after excluding the initial hospitalization costs (mean of $11,228 vs. 3,652). Costs were primarily due to inpatient hospitalizations (mean of $13,059 for the UGI-bleed cohort vs. $729 for the general population cohort) and ambulatory services (mean of $4,037 for the UGI-bleed cohort vs. $1,537 for the general population cohort). Sixteen percent of the UGI-bleed cohort had a GI-related hospitalization, and about 40% of total costs occurred after the initial hospitalization. CONCLUSIONS: Patients with UGI bleeds experienced significantly higher (p< 0.0001) 12-month health-resource utilization and costs than patients without UGI bleeds. This study provides empirical evidence of the long-term economic burden associated with UGI bleeding. Interpretation of the results should take into account the lack of available information in claims data that could have an effect on study outcomes, such as particular clinical and disease-specific parameters that are not mitigated by propensity score and comorbidity index matching. In addition, this study is limited by the intensive demographic matching that was done between the two cohorts, which may have eliminated the sickest UGI patients and the healthiest general health-plan population patients.
Asunto(s)
Hemorragia Gastrointestinal/economía , Costos de la Atención en Salud , Programas Controlados de Atención en Salud/economía , Tracto Gastrointestinal Superior/patología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Hemorragia Gastrointestinal/patología , Indicadores de Salud , Hospitalización/economía , Hospitalización/estadística & datos numéricos , Humanos , Revisión de Utilización de Seguros , Masculino , Programas Controlados de Atención en Salud/estadística & datos numéricos , Persona de Mediana Edad , Análisis Multivariante , Puntaje de Propensión , Estudios Retrospectivos , Resultado del Tratamiento , Estados Unidos , Adulto JovenRESUMEN
BACKGROUND: Zollinger-Ellison syndrome and idiopathic hypersecretion are gastrointestinal hypersecretory conditions requiring long-term maintenance. AIMS: The safety and efficacy data for short-term (6-month) treatment of Zollinger-Ellison syndrome and idiopathic hypersecretion with oral pantoprazole were previously published. This study extends the initial observations to 3 years. METHODS: The primary efficacy end point for this report was the control of gastric acid secretion in the last hour before the next dose of oral pantoprazole (acid output of <10 mmol/h; <5 mmol/h in subjects with prior acid-reducing surgery). Dose titration was permitted to a maximum of 240 mg per 24 h. RESULTS: Twenty-four subjects completed the study. The acid output of 28 of 34 subjects was controlled at initial enrolment. The mean acid output rates were <10 mmol/h throughout the 36 months of treatment for 90-100% of the patients. The majority of the patients were controlled with b.d. doses of 40 or 80 mg pantoprazole at 36 months (acid output was controlled in 24 of 24 subjects). Pantoprazole was generally well tolerated with minimal adverse events reported. CONCLUSIONS: Maintenance oral pantoprazole therapy up to 3 years at dosages of 40-120 mg b.d. was effective and well tolerated in patients with Zollinger-Ellison syndrome and other hypersecretory conditions.
Asunto(s)
Antiulcerosos/uso terapéutico , Bencimidazoles/uso terapéutico , Omeprazol/análogos & derivados , Sulfóxidos/uso terapéutico , Síndrome de Zollinger-Ellison/tratamiento farmacológico , 2-Piridinilmetilsulfinilbencimidazoles , Administración Oral , Anciano , Relación Dosis-Respuesta a Droga , Femenino , Ácido Gástrico/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Omeprazol/uso terapéutico , Pantoprazol , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Both oral bisphosphonates and non-steroidal anti-inflammatory drugs have the potential to irritate the upper gastrointestinal mucosa, and are frequently used by the same patient population. AIM: To determine the rate of upper gastrointestinal adverse events with once weekly alendronate 70 mg and concomitant non-steroidal anti-inflammatory drug use. METHODS: A post hoc analysis was performed on 222 patients who received both medications concomitantly during a 3-month placebo-controlled study. A total of 450 (224 alendronate; 226 placebo) postmenopausal women and men with osteoporosis were randomized. Concomitant non-steroidal anti-inflammatory drug users were defined as patients who received > or =7 continuous days of any dose of a dual cyclo-oxygenase-1 and cyclo-oxygenase-2 inhibiting non-steroidal anti-inflammatory drug, a selective cyclo-oxygenase-2 inhibitor, or aspirin. A survival analysis was performed, and significance assessed. Logistic regression was used to assess consistency of treatment effect on rate of upper gastrointestinal adverse events across non-steroidal anti-inflammatory drug subgroups. RESULTS: Similar percentages of alendronate (52.7%) and placebo (46.0%) patients used non-steroidal anti-inflammatory drugs regularly. Among concomitant non-steroidal anti-inflammatory drug users, 11 alendronate and 11 placebo patients experienced upper gastrointestinal adverse events (9.3% and 10.8%, respectively, P = 0.744). Logistic regression revealed no significant interaction (P = 0.722) between alendronate and concomitant non-steroidal anti-inflammatory drug use. CONCLUSION: Based on this subgroup analysis, once weekly alendronate 70 mg used concomitantly with non-steroidal anti-inflammatory drugs, did not increase upper gastrointestinal adverse events relative to placebo over 3-months.
Asunto(s)
Alendronato/efectos adversos , Antiinflamatorios no Esteroideos/efectos adversos , Enfermedades Gastrointestinales/inducido químicamente , Anciano , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Masculino , Osteoporosis/tratamiento farmacológico , PosmenopausiaRESUMEN
OBJECTIVE: Poor quality has been reported for some generics and other copies of original products. We performed a pilot study to compare the disintegration/dissolution profiles of FOSAMAX (alendronate) 70 mg tablets with those of copies of FOSAMAX that were manufactured outside the United States. RESEARCH DESIGN AND METHODS: We used the standard United States Pharmacopeia (USP) disintegration method to evaluate FOSAMAX 70 mg tablets and 13 copies. At least 12 (n = 12) dosage units were tested for each product (except Fosmin, n = 10). The dissolution profiles of FOSAMAX and one representative copy were also compared. RESULTS: Nine copies (Osteomax, Defixal, Fosmin, Endronax, Osteomix, Genalmen, Fixopan, Osteoplus, and Fosval) disintegrated two- to ten-fold faster than FOSAMAX. Three other copies (Neobon, Regenesis, and Ostenan) disintegrated at least five-fold slower than FOSAMAX. Neobon is a softgel capsule, so special consideration was given to this different dosage form. One copy (Arendal) did not fall into either category but exhibited potentially large inter- and intra-lot variability. Dissolution of alendronate from Regenesis lagged behind that from FOSAMAX. CONCLUSION: Slower disintegration may reduce efficacy because bisphosphonates must be taken in the fasting state and contact with food or even certain beverages severely reduces bioavailability. Faster disintegration (or the use of gel-caps or other alterations to the drug formulation) could increase the risk of esophagitis, an adverse event associated with prolonged contact of the esophagus with bisphosphonates. These disintegration and dissolution results suggest that important differences may exist between FOSAMAX and its copies with regard to bioavailability, pharmacokinetics, and clinical efficacy and safety profiles. Additional testing is warranted to evaluate the pharmacokinetics and clinical safety of these copies.
Asunto(s)
Alendronato/farmacocinética , Medicamentos Genéricos/farmacocinética , Alendronato/química , Disponibilidad Biológica , Medicamentos Genéricos/química , Esofagitis/etiología , Humanos , América Latina , Osteoporosis Posmenopáusica/tratamiento farmacológico , Proyectos Piloto , Seguridad , Solubilidad , Comprimidos , Equivalencia Terapéutica , Agua/químicaRESUMEN
UNLABELLED: Cyclooxygenase (COX)-2 expression and prostaglandin production is increased by Helicobacter pylori infection. Non-selective COX inhibitors reduce prostaglandins and mucosal proliferation in infected mucosa and may reduce gastric cancer risk, but ulceration precludes their use. COX-2 inhibitors cause fewer ulcers and may be chemopreventive. Physiological studies of COX-2 inhibitors in humans with H. pylori infection have not been performed. AIM: To study the impact of COX-2 specific inhibition on gastric prostaglandin levels, H. pylori gastritis and proliferation. METHODS: Twenty infected (eight males, 12 females; age 38 +/- 1.8) and six uninfected (four males, two females; age 36 +/- 3.5) healthy volunteers received rofecoxib 25 mg daily for 14 days. Endoscopic biopsies were evaluated for prostaglandin E2 (PGE2) content, gastritis and proliferation. RESULTS: Before drug therapy, compared to uninfected, H. pylori-infected subjects had significantly higher: (a) gastric mucosal PGE2 (pg/mg tissue) in the gastric body and antrum, (b) H. pylori score in body and antrum and (c) mid-gland proliferation index in antrum and body. The COX-2 inhibitor did not significantly affect PGE2 levels, gastritis scores or proliferation indices in the body or antrum in the H. pylori-positive or -negative subjects. CONCLUSION: The predominant source of increased gastric PGE2 in H. pylori infection appears to be COX-1-derived. In non-ulcerated H. pylori gastritis, COX-2 inhibition does not affect cellular proliferation. Rofecoxib's lack of effect on gastric prostaglandin levels and proliferation in H. pylori-infected mucosa may explain the absence of an increased ulcer risk among COX-2 inhibitor users with H. pylori infection. The lack of significant effect on intermediate biomarkers raises uncertainty regarding the potential of specific COX-2 inhibitors for chemoprevention of gastric cancer.
Asunto(s)
Dinoprostona/metabolismo , Gastritis/microbiología , Infecciones por Helicobacter/prevención & control , Helicobacter pylori , Isoenzimas/antagonistas & inhibidores , Neoplasias Gástricas/prevención & control , Adulto , División Celular , Ciclooxigenasa 2 , Endoscopía Gastrointestinal , Femenino , Estudios de Seguimiento , Mucosa Gástrica/metabolismo , Gastritis/metabolismo , Gastritis/patología , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/patología , Humanos , Lactonas/uso terapéutico , Masculino , Proteínas de la Membrana , Prostaglandina-Endoperóxido Sintasas , Antro Pilórico/metabolismo , SulfonasAsunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Úlcera Péptica/inducido químicamente , Úlcera Péptica/microbiología , Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/efectos adversos , Enfermedades Cardiovasculares/prevención & control , Costo de Enfermedad , Inhibidores de la Ciclooxigenasa/efectos adversos , Inhibidores de la Ciclooxigenasa/uso terapéutico , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Antagonistas de los Receptores H2 de la Histamina/efectos adversos , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Humanos , Úlcera Péptica/economía , Inhibidores de la Bomba de Protones , Estados UnidosRESUMEN
Peptic ulcer disease is a common gastrointestinal disease whose management and treatment has changed dramatically over the last 25 years. Treatment of peptic ulcer disease has evolved from dietary modifications and antacids to gastric acid suppression with H2-receptor antagonists and proton pump inhibitors to eradication of Helicobactor pylori infection. Treatment of patients infected with H pylori using antibiotics has changed the natural history of peptic ulcer disease. As a result of H pylori treatment and other unknown factors ulcer disease is declining and complications from ulcer disease have diminished significantly.
Asunto(s)
Úlcera Péptica/diagnóstico , Úlcera Péptica/terapia , Antiácidos/uso terapéutico , Antibacterianos/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Farmacorresistencia Microbiana , Medicina Familiar y Comunitaria/métodos , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Antagonistas de los Receptores Histamínicos/uso terapéutico , Humanos , Úlcera Péptica/epidemiología , Úlcera Péptica/etiología , Úlcera Péptica/fisiopatología , Atención Primaria de Salud/métodos , Inhibidores de la Bomba de Protones , Factores de Riesgo , Resultado del TratamientoRESUMEN
OBJECTIVES: Whether gastric infection with Helicobacter pylori increases the risk of gastric mucosal injury during long term/low dose aspirin therapy is unknown. We examined whether H. pylori infection enhances upper GI mucosal damage, assessed endoscopically, in volunteers given low dose aspirin. We studied 61 healthy men and women, 29 with and 32 without active H. pylori infection. METHODS: We treated volunteers for 45 days with a placebo or aspirin (either 81 mg every day or 325 mg every 3 days). Gastroduodenal mucosal damage was then assessed by endoscopy, as was gastric histology and ex vivo gastric mucosal prostaglandin E2 and F2alpha synthesis rates. RESULTS: Erosive disease from low dose aspirin (erosions and/or ulcers) occurred in 50% of H. pylori-infected volunteers and in 16% of their noninfected counterparts (p = 0.02). Aspirin caused a significantly higher average mucosal injury score in the gastric antrum in H. pylori-infected participants than in noninfected subjects (p = 0.03), and two H. pylori-infected subjects developed antral gastric ulcers. Subjects with H. pylori gastritis treated with the placebo had nearly 50% higher gastric mucosal prostaglandin (E2 plus F2alpha) synthesis rates than their noninfected counterparts (108 +/- 6 ng/g/min versus 75 +/- 6 ng/g/min, p < 0.001). Aspirin reduced mucosal prostaglandin synthesis to similar levels in infected and noninfected participants. CONCLUSIONS: Long term/low dose aspirin therapy led to more gastric mucosal damage when H. pylori gastritis was present than when it was absent, despite similar degrees of gastric mucosal prostaglandin depletion.
Asunto(s)
Aspirina/efectos adversos , Enfermedades Duodenales/inducido químicamente , Gastritis/complicaciones , Infecciones por Helicobacter/complicaciones , Prostaglandinas/biosíntesis , Gastropatías/inducido químicamente , Adolescente , Adulto , Anticuerpos Antibacterianos/biosíntesis , Aspirina/administración & dosificación , Plaquetas/efectos de los fármacos , Plaquetas/enzimología , Ciclooxigenasa 1 , Método Doble Ciego , Enfermedades Duodenales/complicaciones , Enfermedades Duodenales/metabolismo , Enfermedades Duodenales/microbiología , Úlcera Duodenal/inducido químicamente , Úlcera Duodenal/complicaciones , Úlcera Duodenal/microbiología , Endoscopía Gastrointestinal , Femenino , Mucosa Gástrica/metabolismo , Gastritis/microbiología , Gastritis/patología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/patología , Helicobacter pylori/inmunología , Helicobacter pylori/aislamiento & purificación , Humanos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Isoenzimas/metabolismo , Masculino , Proteínas de la Membrana , Persona de Mediana Edad , Prostaglandina-Endoperóxido Sintasas/metabolismo , Estómago/efectos de los fármacos , Estómago/patología , Gastropatías/complicaciones , Gastropatías/metabolismo , Gastropatías/microbiología , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/complicaciones , Úlcera Gástrica/microbiologíaRESUMEN
OBJECTIVES: We performed a placebo-controlled study to evaluate the effect of low-dose aspirin on serum C-reactive protein (CRP) levels. BACKGROUND: Elevated circulating concentrations of CRP, an inflammatory marker, increase the risk of thrombotic cardiovascular diseases such as myocardial infarction (MI). Moreover, low-dose aspirin therapy has been reported to be more effective in preventing MI in men with higher CRP levels than it is in those with lower levels, raising the possibility that aspirin prevents thrombosis by reducing vascular inflammation. The effect of low-dose aspirin therapy on serum CRP levels in men has been addressed recently, but the results of the two studies conflict. METHODS: Effects of aspirin (81 mg every day or 325, 81 or 40 mg every-third-day given for 31 days) on serum CRP, using a highly-sensitive assay, and on serum platelet-cyclo-oxygenase (COX)-1-derived thromboxane (Tx) B2 concentrations were studied simultaneously in 57 healthy volunteers (30 men and 27 women). RESULTS: Trough platelet COX-1-derived serum Tx B2 concentrations decreased by 100% with daily aspirin and by 90%, 84% and 78% with 325, 81 and 40 mg aspirin every-third-day (p < 0.001). However, there were no significant changes in serum CRP levels from baseline with daily low-dose aspirin therapy, with any of the every-third-day aspirin regimens or with placebo treatment. CONCLUSIONS: Low doses of aspirin that markedly inhibit platelet COX-1 activity, as manifested by a profound decline in platelet-derived serum Tx B2 concentrations, have no detectable effect on serum CRP levels in healthy men and women.
Asunto(s)
Aspirina/administración & dosificación , Proteína C-Reactiva/análisis , Tromboxano B2/sangre , Adulto , Método Doble Ciego , Femenino , Humanos , Inmunoensayo/métodos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Aspirin's antithrombotic effect is mediated predominately by inhibition of platelet cyclooxygenase-1, leading to a decline in serum thromboxane A2 concentrations. We performed a placebo-controlled, randomized, double-blind trial to determine whether aspirin could be given at 3-day intervals and still achieve potent serum thromboxane inhibition. One hundred nine healthy men and women with no recent exposure to aspirin and no contraindications to its use participated. Subjects received 325 mg, 81 mg, or 40 mg of plain aspirin every third day, with placebo on other days; 81 mg of aspirin every day; or placebo every day. Serum concentrations of thromboxane B2 (the metabolite of thromboxane A2) were measured at 3-day intervals during a 31-day treatment period, as well as 4, 7, and 14 days after treatment ended. Serum thromboxane B2 concentrations were nearly identical during treatment with 325 mg of aspirin every third day or 81 mg of aspirin per day (86% inhibition [84%, 89%] and 85% inhibition [73%, 96%], respectively). An aspirin dose of 81 mg every third day was nearly as potent (74% inhibition [70%, 79%]), whereas 40 mg of aspirin every third day achieved only 50% inhibition (40%, 60%). Every-third-day low-dose aspirin regimens (325 and 81 mg) deserve comparison with daily low-dose aspirin regimens in controlled clinical trials because the former regimens could prove to have equal efficacy with reduced toxicity.
Asunto(s)
Aspirina/administración & dosificación , Tromboxanos/sangre , Adolescente , Adulto , Aspirina/efectos adversos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Inhibidores de Agregación Plaquetaria/administración & dosificación , Tromboxano B2/sangre , Factores de TiempoRESUMEN
When considering the diseases of the stomach and duodenum, peptic ulcer disease has been the one of greatest clinical impact. Although there are several components that contribute mechanistically to ulcer disease, it is recognized that gastroduodenal mucosal prostaglandins play a central pathogenic role, especially in ulcers related to the use of NSAIDs. As a result of understanding the mechanisms of NSAID-induced ulceration, the crucial function that gastroduodenal mucosal prostaglandins have in mucosal defense and repair is appreciated. It now is held widely that mucosal prostaglandin deficiency increases susceptibility to ulcer formation and that exogenous administration of supplemental prostaglandins reduces ulcer risk. This article reviews the role that mucosal prostaglandins play in defense of the gastric and duodenal mucosa against injury and ulceration.
Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Úlcera Duodenal/fisiopatología , Prostaglandinas/fisiología , Úlcera Gástrica/fisiopatología , Factores de Edad , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/metabolismo , Úlcera Duodenal/etiología , Úlcera Duodenal/prevención & control , Mucosa Gástrica/fisiología , Infecciones por Helicobacter/complicaciones , Humanos , Mucosa Intestinal/fisiología , Isoenzimas/antagonistas & inhibidores , Proteínas de la Membrana , Misoprostol/uso terapéutico , Prostaglandina-Endoperóxido Sintasas , Prostaglandinas/uso terapéutico , Úlcera Gástrica/etiología , Úlcera Gástrica/prevención & controlRESUMEN
Toxic effects in the upper gastrointestinal tract, primarily complicated gastric and intestinal ulcers, are the most common undesirable effects of the nonsteroidal anti-inflammatory drugs. During the last several years, there have been several advances, both in the laboratory and clinically, toward reducing nonsteroidal anti-inflammatory drugs' gastrointestinal toxicity. Some of these important developments are the delineation of mechanisms of nonsteroidal anti-inflammatory drug-induced gastrointestinal toxicity, identification of groups at highest risk for development of nonsteroidal anti-inflammatory drug-induced gastrointestinal complications, recognition of co-therapies that could reduce nonsteroidal anti-inflammatory drug toxicity, and, most recently, development of classes of nonsteroidal anti-inflammatory drugs with improved gastrointestinal safety profiles. Many of these advances have occurred during the last year. This review focuses on several of the important recent observations that have improved understanding and safety of nonsteroidal anti-inflammatory drugs in the gastrointestinal tract.
RESUMEN
Adenocarcinoma in Barrett's esophagus has been increasing in incidence at a rapid rate for more than two decades. Cyclooxygenase (COX)-2 appears to play an important role in gastrointestinal carcinogenesis, and COX-2 overexpression has been demonstrated both in esophageal adenocarcinomas and in the metaplastic epithelium of Barrett's esophagus. The aim of our study was to determine whether selective inhibition of COX-2 by NS-398 would alter the rates of cell growth and apoptosis in human Barrett's-associated esophageal adenocarcinoma cell lines. COX-1 and COX-2 expression in adenocarcinoma cell lines was determined using reverse transcription-PCR and Western blotting for mRNA and protein, respectively. Esophageal adenocarcinoma cell lines were treated with various concentrations of NS-398 (selective for COX-2 inhibition) and flurbiprofen (selective for COX-1 inhibition). Cell growth was compared in flurbiprofen-treated and untreated tumor cell lines; cell growth and apoptosis were compared in NS-398-treated and untreated tumor cell lines. COX-2 mRNA and protein were detected in two of three cell lines (SEG-1 and FLO); the third cell line, BIC-1, did not express COX-2 mRNA or protein under basal conditions or after stimulation with phorbol 12-myristate 13-acetate. Treatment with COX-1-selective concentrations of flurbiprofen did not affect cell growth in any of the three tumor cell lines. In contrast, treatment with COX-2-selective concentrations of NS-398 significantly suppressed cell growth and increased apoptosis in the cell lines that expressed COX-2 (SEG-1 and FLO), but not in the cell line that did not express COX-2 (BIC-1). We conclude that the administration of a selective inhibitor of COX-2 significantly decreases cell growth and increases apoptosis in Barrett's-associated adenocarcinoma tumor cells that express COX-2. These observations suggest a potential role for selective COX-2 inhibitors in the prevention and treatment of esophageal adenocarcinoma for patients with Barrett's esophagus.
Asunto(s)
Adenocarcinoma/enzimología , Apoptosis/efectos de los fármacos , Neoplasias Esofágicas/enzimología , Isoenzimas/antagonistas & inhibidores , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Antiinflamatorios no Esteroideos/farmacología , Apoptosis/fisiología , Esófago de Barrett/complicaciones , Esófago de Barrett/enzimología , División Celular/efectos de los fármacos , División Celular/fisiología , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/farmacología , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/patología , Flurbiprofeno/farmacología , Expresión Génica , Inhibidores de Crecimiento/farmacología , Humanos , Isoenzimas/biosíntesis , Isoenzimas/genética , Proteínas de la Membrana , Nitrobencenos/farmacología , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Prostaglandina-Endoperóxido Sintasas/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especificidad por Sustrato , Sulfonamidas/farmacología , Células Tumorales CultivadasRESUMEN
Aspirin causes peptic ulcers predominately by reducing gastric mucosal cyclooxygenase (COX) activity and prostaglandin synthesis. Because aspirin circulates for only a few hours, we hypothesized that aspirin's inhibitory effect on gastric COX activity must be prolonged. We performed a placebo-controlled experiment in healthy humans to determine the duration of inhibition of aspirin on gastric mucosal COX activity (PGE(2) and PGF(2alpha) synthesis rates). Recovery of gastric COX activity after stopping aspirin was slow and linear. Seventy-two hours after 325-mg aspirin, gastric COX activity was still reduced by 57% (P < 0.001). Duration of inhibition of gastric COX activity was estimated to be 7-8 days after 325-mg aspirin and 5 days after 81-mg aspirin. Recovery of gastric prostaglandin synthesis after 325-mg but not after 81-mg aspirin occurred at slower rates in subjects with Helicobacter pylori-associated gastritis than in those with normal histology. In conclusion, aspirin inhibits gastric COX activity for much longer than predicted from its pharmacokinetic profile, explaining why aspirin at widely spaced intervals is ulcerogenic.
Asunto(s)
Aspirina/efectos adversos , Plaquetas/enzimología , Inhibidores de la Ciclooxigenasa/efectos adversos , Mucosa Gástrica/enzimología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Adolescente , Adulto , Aspirina/administración & dosificación , Inhibidores de la Ciclooxigenasa/administración & dosificación , Dinoprost/biosíntesis , Dinoprostona/biosíntesis , Femenino , Mucosa Gástrica/microbiología , Gastritis/metabolismo , Gastritis/microbiología , Infecciones por Helicobacter/metabolismo , Helicobacter pylori , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/microbiología , Tromboxano A2/sangre , Factores de TiempoRESUMEN
Toxic effects in the upper gastrointestinal tract, primarily complicated gastric and intestinal ulcers, are the most common undesirable effects of the nonsteroidal antiinflammatory drugs (NSAIDs). During the last several years there have been several advances, both in the laboratory and clinically, toward reducing NSAIDs' gastrointestinal toxicity. Some of these important developments have been the delineation of mechanisms of NSAID-induced GI toxicity, identification of groups at highest risk for development of NSAID-induced gastrointestinal complications, recognition of co-therapies that could reduce NSAID toxicity, and, most recently, development of classes of NSAIDs that have an improved gastrointestinal safety profile. Many of these advances occurred during the last year. This review focuses on several of the important recent observations that have improved our understanding and the safety of NSAIDs in the gastrointestinal tract.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Inhibidores de la Ciclooxigenasa/uso terapéutico , Antiinflamatorios no Esteroideos/efectos adversos , Artritis Reumatoide/tratamiento farmacológico , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa/efectos adversos , Humanos , Isoenzimas , Proteínas de la Membrana , Osteoartritis/tratamiento farmacológico , Úlcera Péptica/inducido químicamente , Prostaglandina-Endoperóxido SintasasRESUMEN
Gastric acid secretion, gastrin release, gastric emptying, and gastroesophageal acid reflux were measured in asymptomatic individuals before and after elimination of Helicobacter pylori gastritis. After basal gastric acid secretion and serum gastrin concentrations were measured, meal-stimulated gastric acid secretion and gastrin release were assessed during in vivo intragastric titration to pH 3. Experiments were repeated 4 wk after treatment with lansoprazole, amoxicillin, and clarithromycin. Esophageal pH was also monitored for 24 h before and after therapy. Basal gastric acidity increased approximately 20 mmol/l in subjects whose infection was eradicated (P < 0.05) but not in those with persistent infection. Basal and meal-stimulated gastric acid secretion did not change after H. pylori eradication, despite a 41% reduction in meal-stimulated gastrin release (P < 0.05). Gastroesophageal acid reflux increased two- to threefold after successful treatment (P < 0. 05) but did not change in subjects with persistent infection. Thus elimination of H. pylori gastritis increases gastric acidity, probably by reducing nonparietal alkaline secretion, and this may facilitate gastroesophageal acid reflux.