RESUMO
In patients under oral anticoagulation therapy, the risk of haemorrhage following surgery must be balanced with the risk of thrombo-embolism induced by its discontinuation. Dental surgery is usually safe. Indirect anticoagulation may be continued provided rigorous surgical techniques and careful local hemostasis are applied.
Assuntos
Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Procedimentos Cirúrgicos Bucais/efeitos adversos , Hemorragia Pós-Operatória/etiologia , Tromboembolia/etiologia , 4-Hidroxicumarinas , Administração Oral , Anticoagulantes/administração & dosagem , Hemostasia , Humanos , Indenos , Hemorragia Pós-Operatória/prevenção & controle , Fatores de Risco , Tromboembolia/prevenção & controle , Vitamina K/antagonistas & inibidoresAssuntos
Anti-Inflamatórios não Esteroides/farmacologia , Cetoprofeno/farmacologia , Fator de Ativação de Plaquetas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Bovinos , Infusões Intravenosas , Cetoprofeno/administração & dosagem , Masculino , Agregação Plaquetária/fisiologiaRESUMO
The in vivo ability of the specific PAF-antagonist WEB 2086, a thienotriazolodiazepine, to inhibit platelet-activating factor (PAF) in cattle was investigated by in vitro determination of platelet aggregation curves. WEB 2086 was infused intravenously into a group of 5 healthy male Friesian calves in a dose of 3 mg/kg over 1 min. The resultant inhibition peaked between 30 min and 1 h after administration of WEB 2086. The inhibition was significantly reduced after 3 h and became non-significant after 6 h, but maximal pre-treatment aggregation had not been restored by 24 h after the injection of WEB 2086. These results confirm previous results obtained in vitro and suggest that WEB 2086 is a potent antagonist of PAF activity in calves. They also suggest that further clinical studies with WEB 2086 in cattle are desirable.
Assuntos
Azepinas/farmacologia , Bovinos/sangue , Fator de Ativação de Plaquetas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Triazóis/farmacologia , Animais , Azepinas/administração & dosagem , Bovinos/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/veterinária , Infusões Intravenosas/veterinária , Masculino , Agregação Plaquetária/fisiologia , Inibidores da Agregação Plaquetária/administração & dosagem , Fatores de Tempo , Triazóis/administração & dosagemRESUMO
The effect of the specific PAF-antagonist WEB 2086, a thieno-triazolo-diazepine, and ketoprofen, a NSAID, was investigated on PAF-induced bovine platelet aggregation measured ex vivo in platelet-rich plasma (PRP). WEB 2086 was infused intravenously over 1 min followed immediately by ketoprofen administration over 1 s (both drugs = 3 mg/kg), in a group of six healthy male Friesian calves. Depending on the PAF concentration, a reversible (10(-8)-10(-9) mol/l) and irreversible (10(-5)-10(-7) mol/l) platelet aggregation was observed. The reversible aggregation was completely blocked by pretreatment of the animal with WEB 2086 and ketoprofen. The inhibitory effects observed during the irreversible aggregation were 47.22%, 54.00% and 88.00% at 10(-5), 10(-6) and 10(-7) mol/l PAF, respectively. Moreover, the aggregation obtained in these condition became reversible. Maximal inhibitory effect of WEB 2086 and ketoprofen on PAF-induced platelet aggregation in calves was observed within 30 min after administration of both drugs. This inhibition persisted even after 24 h and was significantly different from control with P < 0.05. The combined effect of both drugs exceeded the sum of the individual effects (synergism). It was concluded that WEB 2086 and ketoprofen very effectively blocked PAF-induced bovine platelet aggregation in platelet-rich plasma. The study also suggested a synergism between both substances.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Azepinas/farmacologia , Bovinos/sangue , Cetoprofeno/farmacologia , Fator de Ativação de Plaquetas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Triazóis/farmacologia , Análise de Variância , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Azepinas/administração & dosagem , Bovinos/fisiologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Infusões Intravenosas/métodos , Infusões Intravenosas/veterinária , Cetoprofeno/administração & dosagem , Masculino , Fator de Ativação de Plaquetas/administração & dosagem , Agregação Plaquetária/fisiologia , Inibidores da Agregação Plaquetária/administração & dosagem , Fatores de Tempo , Triazóis/administração & dosagemRESUMO
The sensitivity of bovine platelet aggregation in response to PAF stimulation and the ability of WEB 2086 (a thieno-triazolodiazepine) to inhibit response to PAF-induced platelet aggregation were investigated in the blood from five healthy male Belgian Blue calves. The recorded response to PAF showed a plateau which was dependent on the PAF concentration. Platelet aggregation induced by PAF consists of two mechanisms: reversible and irreversible aggregations which are accompanied by the release of platelet granule contents. Reversible aggregation occurred above (2 . 10(-9) mol/l) PAF, and irreversible aggregation occurred above (2 . 10(-7) mol/l) PAF. Addition of WEB 2086 to bovine platelets in vitro induced a rightward shift in the dose-response curve to PAF. WEB 2086 inhibited PAF-induced aggregation in a competitive reversible manner (pA2 = 7.61). The results of our study show that PAF induces platelet aggregation in platelet-rich plasma (PRP) and that addition of WEB 2086 to bovine platelets in vitro inhibits PAF-induced Platelet Aggregation.
