ABSTRACT
The plant world represents an important source of potential therapeutic agents, but concomitant administration of herbal and conventional medications may result in interactions with subsequent beneficial or adverse effects. This study was designed to examine the analgesic effect of thyme tincture and thyme syrup, two commonly used thyme formulations, and their interactions with codeine, paracetamol, pentobarbital and diazepam in mice. The identification and quantification of thymol and carvacrol were carried out by GC/MS and GC/FID. The analgesic activity was studied using a hot plate method. Effects of thyme syrup on diazepam-induced motor coordination impairment in rotarod test and on pentobarbital-induced sleeping time were also determined. Thymol (175.3 µg/mL and 9.73 µg/mL) and carvacrol (10.54 µg/mL and 0.55 µg/mL) concentrations were measured in tincture and syrup, respectively. Thyme syrup and tincture exhibited effective analgesic activity in the hot plate pain model. Pretreatment with thyme formulations reduced analgesic activity of codeine, and potentiated the analgesic activity of paracetamol. Co-administration of thyme formulations has led to potentiation of diazepam and pentobarbital depressive central nervous system effects. Thyme formulations interacted with tested conventional drugs, probably through interference with their metabolic pathways and succeeding altered concentrations and pharmacological effects.
Subject(s)
Animals , Male , Female , Mice , Thymus Plant/drug effects , Drug Interactions , Analgesics/adverse effects , Pentobarbital/adverse effects , Pharmaceutical Preparations , Diazepam/adverse effects , Phytotherapeutic DrugsABSTRACT
Little research has been done with propofol in relation to renal function. The aim of this study was to evaluate the effects of continuos infusion of propofol on renal function in dogs. Sixteen dogs, previously anesthetized with pentobarbital sodium (30mg.Kg-1) for surgical preparation, catheterism and monitoring, were studied. The dogs were mechanically ventilated with air and received alcuronium (0.2mg.Kg-1 in bolus and 0.6mg.Kg-1 - maintenance). The following parameters were studied: heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), aortic blood flow (AoBF - by electromagnetic flowmeter installed in the ascending aortic), aortic vascular resistance index (AoVRI), renal plasma flow (ERPF - by para-aminohipurate clearance), glomerular filtration rate (GFR - by creatinine clearance), effective renal blood flow (ERBF = ERPF/1 - hematocrit), urinary volume (UV), renal vascular resistance (RVR = MAP.80/ERBF.10-3), urinary sodium excretion (UENa), fractionated sodim excretion (FENa), osmolar clearance (Cosm) and free water clearance (CH2o). These parameters were studied at 15 (M1), 30 (M2), 45 (M3) and 60 (M4) min after beginning pentobarbital sodium infusion (5mh.Kg-1.h-1). The dogs were allocated into two groups of eight animals each: G1 (control-pentobarbital sodium) and G2 (propofol). In G1, pentobarbital was given at the four times studied. G2 dogs received the same treatment as G1 dogs at M1 and M2; infusion of pentobarbital was substituted by propofol (3mg.Kg-1 bolus, followed by 12mg.Kg-1.h-1 continuous infusion) at M3 and M4. Profile Analysis was used to analyze the results statistically. In G1 (pentobarbital), there was a significant increase in RVR (M1