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Biomedical subjects

A I Alvarez

Publications and source records attributed to A I Alvarez.

26 records · Page 2Linked to original sources
PubMed1994

Influence of ethanol on gastric absorption and metabolism of albendazole and mebendazole.

The effect of ethanol administration on gastric absorption in rats of two benzimidazole derivatives has been studied. The ethanol administration was carried out as both acute (5%, 10% and 15% w/v of ethanol in the perfusion solution), and chronic (15, 30 and 120 days) forms. Two benzimidazole derivatives were used: albendazole (ABZ) and mebendazole (MBZ). The administration of ethanol did not affect the kinetic mechanism of the absorption process (simple diffusion) but the absorption rate decreased in all treatments except in 5% acute ethanol, presumably due to the improved solubility of the drugs. Plasma, bile and liver levels after gastric perfusion suggest a possible interference of ethanol metabolism with drug hepatic metabolism.

Albendazole↗
PubMed1993

Randomised controlled trial of efficacy of albendazole in intra-abdominal hydatid disease.

The efficacy of albendazole in hydatid disease is still unclear, because there has been no study that assessed the status of the parasite after treatment. The significance of albendazole-induced echographic changes in the cyst therefore cannot be judged. We did a prospective, controlled, randomised, open study of albendazole in patients with liver hydatid disease, and assessed parasite viability after treatment. 18 patients received no albendazole treatment (controls), 18 received albendazole (10 mg/kg daily) for 1 month (group A), and 19 received the drug for about 3 months (group B). Echography was done before and during treatment; all patients underwent surgery on completion. Parasite (protoscolex viability and development of cysts in mice) and ultrastructure studies were done for all cysts removed. 8 (50%) of cysts in the control group, 13 (72%) in group A, and 16 (94%) in group B were non-viable (p = 0.015). Protoscolex and cyst viability were significantly (p = 0.039 and p = 0.018, respectively) lower in treated patients than in controls. Treatment was also significantly associated with total cyst membrane disintegration. 68% of cysts treated for 3 months showed echographic changes, and only 1 of 20 cysts showing echographic changes during treatment was judged viable. The efficacy of albendazole at a dose of 10 mg/kg daily for 3 months suggests that it is a suitable alternative to surgery in uncomplicated hydatid liver disease, as initial treatment.

Adult↗
PubMed1992

Albendazole and mebendazole uptake by isolated enterocytes.

Uptake of albendazole (ABZ) and mebendazole (MBZ) by isolated rat enterocytes was carried out. These drugs, widely used oral anthelmintics, exhibit a scarce water solubility which reduce its absorption by the oral tract. The present study was designed to assess the captation for ABZ and MBZ in different enterocyte populations isolated from upper to crypt villus. The concentration range used for the absorption experiments was within 10-500 microM for both drugs, using DMSO as solvent. The results obtained show the existence of a passive mechanism for the uptake of ABZ and MBZ at concentrations between 10 and 100 microM, with a maximum intake value around 20 microM/mg protein. No differences were found with respect to the cell populations analyzed. The drug uptake levels seem to be higher for MBZ than for ABZ prior to reaching the maximum plateau.

Albendazole↗
PubMed1992

Erythrocyte metabolism in exercise. A comparative study in anaemized rats.

The influence of young red cells induced by anaemization on physical performance had been studied in rats. The anemic rats with immature red cells, higher levels of ATP, glutamate-oxalacetate transaminase (GOT) and lactate dehydrogenase (LDH) showed an elevated lactate and ammonia concentration at the first week of training. The blood analysis also showed that the rise in 2,3-DPG concentration can be related with the increase of glycolytic activity during exercise in both groups, anemic and non anemics rats.

2,3-Diphosphoglycerate↗
PubMed1991

Effects of ethanol on the pharmacokinetics of cephalexin and cefadroxil in the rat.

Data are presented on the effect of ethanol on the intestinal absorption and excretion in rats of two beta-lactam antibiotics, cephalexin (CFX) and cefadroxil (CFD). A recirculating perfusion technique within an antibiotic concentration range of 0.5 to 50 mM was used. Ethanol was administered either in an acute form into the intestine or in a chronic form as a 15% drinking solution for 2 months. The results are normalized in relation to the metabolic body weight, intestinal length, and osmotic conditions. Acute ethanol treatment decreases the antibiotic absorption; biliary excretion of CFD is increased, while urinary excretion of CFX is lowered. Chronic treatment shows slight negative effects on the absorption of CFX and CFD. Results are interpreted on the basis of the effect of ethanol on biological membranes. Enhanced urinary excretion after acute ethanol treatment, as well as differences between transport mechanisms, are invoked to explain these effects.

Administration, Oral↗
PubMed1991

Comparative study on gastric absorption of albendazole and mebendazole in rats.

1. A study was carried out to determine the kinetics of the gastric absorption of two wide spectrum benzimidazole anthelmintics, albendazole and mebendazole. 2. The method used was gastric recirculation of solutions containing the drugs in concentrations ranging from 0.5 to 100 mM. 3. The results obtained showed that absorption corresponds to first order kinetics, with diffusion constants of 0.0087 min-1 for albendazole and 0.0077 min-1 for mebendazole. 4. Blood levels of the drugs for the whole range of concentrations were always higher in the case of albendazole.

Absorption↗
PubMed1988

Kinetic mechanism for the intestinal absorption of ofloxacin.

The absorptive behaviour of ofloxacin, a quinolone antibacterial agent, was studied following recirculation in small intestine of both male and female rats, at initial doses ranging from 0.125 to 5 mg mL-1. A saturable Michaelis-Menten process is suggested to explain the intestinal absorption. No significant differences were found in the absorption parameters per metabolic weight unit.

Animals↗