Pharmacokinetic-interaction of Vitex negundo Linn. & paracetamol.

Background & objectives: Currently, herbal preparations are clinically used as functional food, food supplements or as add on therapy, which affects the bioavailability and also the net therapeutic potential of co-administered allopathic drugs. Therefore, it is important to assess the interaction among these two classes of drugs. Here we studied the interaction between orally-administered ethanolic extract of leaves of Vitex negundo Linn. (Verbenaceae) (VN extract) and paracetamol in albino rats. Method: Solvent free dried extract of VN leaves was orally given to experimental rats in different doses (62.5-1000 mg/kg/b.wt.), daily for six consecutive days. On days 3 and 6, paracetamol (100 mg/kg/b.wt.) was orally administered to these extract treated rats and control rats (drug vector). At various time intervals (5 min - 120 min), blood was collected from each animal and paracetamol concentration was determined in plasma by using HPLC with UV detector at 249 nm. Various pharmacokinetic parameters were calculated by non compartmental model. Results: A significant decline in plasma concentration of paracetamol with time-gap was recorded with the increasing dose of VN extract, without affecting its Tmax (maximum time to achieve peak plasma concentration). There was a significant decrease in the extent of absorption and decline in intensity of therapeutic response (as evidenced by reduced AUC value and decline in Cmax). Further, compared to control, the relative bioavailability of paracetamol, in presence of VN extract, decreased significantly. Interpretation & conclusions: VN extract or its ayurvedic formulation if co-administered with allopathic drug like paracetamol, the dose of allopathic drug needs to be adjusted in order to achieve desired therapeutic response of paracetamol.

Biodistribution of samarium-153-EDTMP in rats treated with docetaxel / Biodistribuição de EDTMP-153-samário em ratos tratados com docetaxel

PURPOSE: Many patients with metastatic bone disease have to use radiopharmaceuticals associated with chemotherapy to relieve bone pain. The aim of this study was to assess the influence of docetaxel on the biodistribution of samarium-153-EDTMP in bones and other organs of rats. METHODS: Wistar male rats were randomly allocated into 2 groups of 6 rats each. The DS (docetaxel/samarium) group received docetaxel (15 mg/kg) intraperitoneally in two cycles 11 days apart. The S (samarium/control) group rats were not treated with docetaxel. Nine days after chemotherapy, all the rats were injected with 0.1ml of samarium-153-EDTMP via orbital plexus (25µCi). After 2 hours, the animals were killed and samples of the brain, thyroid, lung, heart, stomach, colon, liver, kidney and both femurs were removed. The percentage radioactivity of each sample ( percent ATI/g) was determined in an automatic gamma-counter (Wizard-1470, Perkin-Elmer, Finland). RESULTS: On the 9th day after the administration of the 2nd chemotherapy cycle, the rats had a significant weight loss (314.50±22.09g) compared (p<0.5) to pre-treatment weight (353.66± 22.8). The percent ATI/g in the samples of rats treated with samarium-153-EDTMP had a significant reduction in the right femur, left femur, kidney, liver and lungs of animals treated with docetaxel, compared to the control rats. CONCLUSION: The combination of docetaxel and samarium-153-EDTMP was associated with a lower response rate in the biodistribution of the radiopharmaceutical to targeted tissues. Further investigation into the impact of docetaxel on biodistribution of samarium-153-EDTMP would complement the findings of this study.

OBJETIVO: Muitos pacientes com metástases ósseas são tratados com radiofármacos associados com quimioterapia para alívio da dor óssea. O objetivo do trabalho foi estudar a influência do docetaxel na biodistribuição do EDTMP-153-samário nos ossos e outros órgãos de ratos. MÉTODOS: Ratos Wistar foram aleatoriamente alocados em 2 grupos de 6 animais cada. O grupo DS (docetaxel/samário) recebeu docetaxel (15 mg/kg) intraperitoneal em dois ciclos com 11 dias de intervalo. Os ratos do grupo S (samário/controle) não foram tratados com docetaxel. Nove dias após a quimioterapia, todos os animais receberam 0,1ml de EDTMP-153-samário via plexo orbital (25µCi). Após 2 horas, os animais foram mortos e feitas biópsias de cérebro, tireóide, pulmão, coração, estômago, cólon, fígado, rim e fêmures. O percentual de radioatividade por grama ( por centoATI/g) de tecido de cada biópsia foi determinado em contador gama automático (Wizard-1470, Perkin-Elmer, Finland). RESULTADOS: No 9º após 2º ciclo de docetaxel os ratos tiveram perda de peso significante, passando de 353,66± 22,8g (controle/pré-tratamento) para 314,50±22,09g (p<0,5). Os por cento ATI/g nos órgãos dos ratos tratados com EDTMP-153-samário e docataxel tiveram redução significante nos fêmures direito e esquerdo, rim, fígado e pulmão, quando comparados com os não tratados com docetaxel. CONCLUSÃO: A combinação de docetaxel com EDTMP-153-samário foi associada com resposta mais baixa na biodistribuição do radiofármaco em órgãos alvo. Futuras investigações sobre o impacto do docetaxel na biodistribuição do EDTMP-153-samário poderão complementar os achados teste estudo.

Comparative bioavailability of paracetamol.

Prescribing brand name versus generic drugs continues to be a controversial issue. The harmful effects of nonequivalence result from either too little or too much drug reaching the patient which will cause either failure of treatment or adverse drug reactions. On the other hand, if physicians prescribe higher priced original drugs instead of therapeutically equivalent lower cost generic drugs to their patients, the patients then have to pay for the added cost. This study was designed to compare the bioavailability of paracetamol of a generic versus original drug. The original brand (Tylenol, Cilag) which was assigned as the reference standard against another generic formulation (Sara, Thai Nakorn Patana). Ten healthy male volunteers aged 20 to 45 years participated in this study. The study was conducted as a cross-over experimental design. The dose was 2 tablets of 500 mg. In conclusion, based on the concentration-time curve and pharmacokinetic analysis there were no statistically significant differences between T1/2 absorption and Cmax. Although AUC of Sara was marginally statistically greater than Tylenol, this magnitude of difference probably has no clinical significance. All these parameters are within the accepted 20 per cent difference, indicating these products are bioequivalent.

Evaluación de la eficacia y la seguridad del tolmetín sódico como antipirético jen niños con infecciones de las vías respiratorias superiores / Evaluation of efficacy and safety of sodium tolmetin as an antipiretic in children with upper respiratory tract infections

Se evaluó la eficacia y la seguridad del tolmetín sódico como antipirético en niños con una de las siguientes afecciones de las vías respiratorias superiores: faringoamigdalitits, faringitis, sinusitis, otitis o amigdalitis. La muestra estuvo formada por 83 niños a los que se administró el fármaco en dosis de 20-30 mg/kg/día, fraccionados en tres a cuatro dosis por vía oral. Se interrogó a los padres para seguir la evolución del tratamiento. Se obtuvo mejoría de toda la sintomatología a los cinco días de tratamiento

Efectividad del fenobarbital, diazepam y antipirético para prevenir recurrencias en niños con una primera convulsión febril

El propósito de este estudio fue comparar la efectividad de estos tres tipos de tratamiento para prevenir las recurrencias de las convulsiones febriles durante el primer año posterior a la primera convulsión febril. Se trata de un trabajo prospectivo, tipo ensayo clínico controlado, abierto, no aleatorio. Se incluyeron finalmente 87 niños que consultaron al servicio de urgencias del Hospital Militar Central, por presentar una primera convulsión febril durante el período comprendido entre marzo de 1990 a junio de 1992. Los tres grupos de tratamiento se recomendaron así: fenobarbital como profilaxis continua 5 mg/Kg/día; diazepam 0,5 mg/Kg sublingual o rectal cada 12 horas en caso de presentar fiebre y acetaminofen 10 mg/Kg cada seis horas también en caso de fiebre. Presentaron recurrencias 2/29 pacientes tratados con diazepam, 9/28 niños tratados con fenobarbital y 12/30 casos que recibieron acetaminofen. Encontrándose una diferencia estadísticamente significativa (p<0.025) a favor del tratamiento con diazepam. En este trabajo no se encontró ninguna justificación para continuar recomendando la administración continua de fenobarbital en niños sanos con convulsiones febriles.