Metronidazole concentration in the bloodstream following its topical application, at different concentration levels, on experimental skin wounds during healing by secondary intention

Abstract Purpose: To characterize qualitatively and quantitatively the absorption of metronidazole solution, in greater concentrations and for longer periods, when applied topically to an experimental open skin wound model. Methods: An open skin wound, 2 cm in diameter and total skin thickness was prepared, under anesthetic, in the dorsal region of 108 Wistar rats weighing between 300 and 350 grams. The animals were allocated to groups of 18 animals in accordance with the concentration of metronidazole in the solution to be applied daily to the wound. In the control group (CG), 0.9% sodium chloride solution was used for application, and in the experimental groups (GI, GII, GIII, GIV and GV) metronidazole solution at 4%, 6%, 8%, 10% and 12%, respectively, was applied. After 3, 7 and 14 days of treatment. Blood samples collected through cardiac puncture were examined for the existence or non-existence of metronidazole, using high performance liquid chromatography (HPLC). Detected metronidazole values were compared statistically within each group (temporal analysis 3 days X 7 days X 14 days) and between the groups that used topical metronidazole (4% X 6% X 8% X 10% and 12%) using the Kruskal-Wallis test, considering a statistical significance of 95% (p<0.05). Results: Metronidazole was detected in all the samples at all times in all the groups in which topical metronidazole was applied to the wounds. Characteristically, there was no significant difference between the doses obtained within each group over time (3 days X 7 days X 14 days) GI=0.461; GII=0.154; GIII=0.888; GIV= 0.264 and GV=0.152. In the evaluation between groups, a similar degree of absorption was found after 3 days (p=0.829) and 14 days (p=0.751). Conclusion: The serum concentration of metronidazole that was achieved was not influenced by the concentration of the solution applied to the skin wound, with similar extend, or by the duration of the application.

Concentraciones sanguíneas de sulfadoxina y pirimetamina según la respuesta terapéutica antimalárica, en dos municipios de Antioquia, Colombia / Blood levels of sulfadoxine and pyrimethamine, according to the malaria-treatment response, in two municipalities of Antioquia, Colombia

PROBLEMA: Se ha observado un aumento constante del índice de fracaso terapéutico de la combinación sulfadoxina-pirimetamina (SDX-PIR) en el tratamiento de la malaria por Plasmodium falciparum sin complicaciones. OBJETIVO: Cuantificar, mediante cromatografía de líquidos de alta resolución (HPLC), las concentraciones sanguíneas de SDX-PIR en pacientes con buena respuesta clínica y sin respuesta al tratamiento. MÉTODOS: En 2002 se llevó a cabo un estudio experimental con asignación aleatoria y sin anonimato para evaluar el tratamiento con la combinación SDX-PIR en una población de 79 pacientes de dos municipios del departamento de Antioquia en Colombia (Turbo: 45; Zaragoza: 34), de uno y otro sexo y de 1 a 60 años de edad, con malaria por Plasmodium falciparum sin complicaciones y una densidad de parasitemia de 500 a 50 000 anillos/æL. El tratamiento consistió en una sola dosis, administrada bajo supervisión médica, de SDX (25 mg/kg) y PIR (1,25 mg/kg) combinadas en comprimidos (500 mg y 25 mg de SDX y PIR, respectivamente) y se realizó seguimiento clínico y parasitológico por 21 días. Las concentraciones de SDX y PIR se midieron dos horas después de la administración del medicamento y el día del fracaso terapéutico en los casos en que se produjo. RESULTADOS: A las 2 horas de haberse administrado el medicamento la concentración sanguínea mediana de SDX fue de 136,6 æmol/L en los pacientes que mostraron respuesta clínica adecuada y de 103,4 æmol/L en quienes no respondieron al tratamiento (P = 0,13). La mediana de PIR fue 848,4 y 786,1 nmol/L en pacientes con respuesta clínica adecuada y fracaso terapéutico, respectivamente (P = 0,40). Las concentraciones tampoco mostraron diferencia significativa entre los casos de fracaso temprano y tardío. La correlación lineal entre las concentraciones de SDX y PIR fue cercana a cero (r = 0,13). DISCUSION Y CONCLUSIONES: Con respecto a 1998, el fracaso del tratamiento con la combinación SDX-PIR aumentó de 13 por ciento a 22 por ciento en Turbo y de 9 por ciento a 26 por ciento en Zaragoza. La falta de respuesta en 2002 no pudo explicarse por concentraciones (menores) de los medicamentos en sangre.

Plasma hydroxy-metronidazole/ metronidazole ratio in hepatitis C virus-induced liver disease

It has been suggested that the measurement of metronidazole clearance is a sensitive method for evaluating liver function. The aim of this study was to evaluate the usefulness of plasma hydroxy-metronidazole/metronidazole ratios as indicators of dynamic liver function to detect changes resulting from the various forms of chronic hepatitis C virus (HCV) infection. A total of 139 individuals were studied: 14 healthy volunteers, 22 healthy, asymptomatic, consecutive anti-HCV-positive HCV-RNA negative subjects, 81 patients with chronic hepatitis C (49 with moderate/severe chronic hepatitis and 34 with mild hepatitis), and 20 patients with cirrhosis of the liver. HCV status was determined by the polymerase chain reaction. Plasma concentrations of metronidazole and its hydroxy-metabolite were measured by reverse-phase high-performance liquid chromatography with ultraviolet detection in a blood sample collected 10 min after the end of a metronidazole infusion. Anti-HCV-positive HCV-RNA-negative individuals demonstrated a significantly reduced capacity to metabolize intravenously infused metronidazole compared to healthy individuals (0.0478 ± 0.0044 vs 0.0742 ± 0.0232). Liver cirrhosis patients also had a reduced plasma hydroxy-metronidazole/metronidazole ratio when compared to the other groups of anti-HCV-positive individuals (0.0300 ± 0.0032 vs 0.0438 ± 0.0027 (moderate/severe chronic hepatitis) vs 0.0455 ± 0.0026 (mild chronic hepatitis) and vs 0.0478 ± 0.0044 (anti-HCV-positive, HCV-RNA-negative individuals)). These results suggest an impairment of the metronidazole metabolizing system induced by HCV infection that lasts after viral clearance. In those patients with chronic hepatitis C, this impairment is paralleled by progression of the disease to liver cirrhosis.

Multiple dose pharmacokinetics of ciprofloxacin in preterm babies.

BACKGROUND: Ciprofloxacin is increasingly used in preterm neonates to treat multi-drug resistant infections, however the pharmacokinetics of this drug in preterm newborns is not well studied. OBJECTIVES: To determine the multi-dose pharmacokinetics of intravenous ciprofloxacin in pre-term infants. DESIGN: Prospective, cohort study. SETTING: Level III Neonatal Intensive Care Unit in a tertiary Care hospital in North India. METHODS: 24 preterm neonates with age < 28 days, who received intravenous ciprofloxacin 10 mg/kg/dose 12 hourly for clinical and/or culture proven sepsis, were enrolled. Serum levels of ciprofloxacin were analyzed after first dose on day 1 and at the end of days 3 and 7. Results: Of 24 babies included in the study [mean gestation (SD) 32 wks (2.4 wks)], 3 died and 1 dropped out in the initial few days, leaving 20 patients whose data on serum ciprofloxacin were available. Peak values on days 1, 3 and 7 were [mean +/- SEM] 2.3 +/- 0.39 microg/mL, 3.0 +/- 0.44 microg/mL and 2.7 +/- 0.39 microg/mL respectively (P >0.05). Trough values on these days were 0.7 +/- 0.14 microg/mL 0.8 +/- 0.14 microg/mL and 1.0 +/- 0.21 microg/mL respectively (P > 0.05). There were no differences between the <1500 g and > 1500 g sub-groups and the < 7 days and >7 days sub-groups with respect to the corresponding peak and trough values on days 1, 3 and 7. The 95% C.I. of serum concentrations were above the MIC90 for most Enterobacteriaceae species, however the lower bound of the 95% C.I. of the mean trough levels was lower than MIC90 for Pseudomonas aeruginosa and Staphylococcus aureus. No adverse effects were observed. CONCLUSIONS: Intravenous ciprofloxacin in a dose of 10 mg/kg/dose 12 hourly is an effective treatment of neonatal sepsis, but higher doses may be required for treating Staphylococcus aureus and Pseudomonas.

Furazolidone in typhoid fever--correlation of clinical efficacy with serum bactericidal activity.

Treatment of typhoid fever with furazolidone produces a high cure rate. This is a clinical curiosity, as furazolidone is described to be poorly absorbed. The present study examined whether furazolidone could produce unequivocal clinical response and, if so whether this was due to the drug producing bactericidal levels in the serum. Twenty one patients selected by defined criteria were treated with furazolidone and evaluated for definite clinical response in 5-7 days. Bactericidal activity of pre dose and post dose sera were estimated in seven patients showing definite clinical response. All the seven patients had a clinical cure without the drug producing significant bactericidal levels in the blood. Hence we concluded that the major site of action of furazolidone was in the intestine. It is our postulate that the organisms reaching the intestine in large numbers from bile are prevented from gaining re-entry into the circulation by the action of furazolidone in the intestine. After repeated cycles of entry of organisms into the intestine from bile and the simultaneous prevention of its re-entry into the circulation, the number of organisms remaining in circulation comes down considerably, thus helping the immune system to bring about a cure.