Toxicity studies in mice of common spices, Cinnamomum zeylanicum bark and Piper longum fruits.

Acute (24 hours) and chronic (90 days) oral toxicity studies on the ethanolic extracts of common spices Cinnamomum zeylanicum Nees bark and Piper longum L. fruits were carried out in mice. Acute dosages were 0.5, 1.0 and 3 g/kg while the chronic dosage was 100 mg/kg/day. All external morphological, hematological and spermatogenic changes, in addition to body weight and vital organ weights, were recorded. The extracts of both the plants caused no significant acute or chronic mortality compared to the control during this study. During chronic treatment there was no significant change in the pre- and post treatment body weight of the test animals while the weight gain in the control group was significant. C. zeylanicum treatment caused reduction in liver weight while P. longum caused a significant increase in the weight of the lungs and spleen of the treated animals compared to the control. Hematological studies revealed a significant fall in hemoglobin level of C. zeylanicum treated animals. Both of the extracts induced a significant increase in reproductive organ weights, sperm motility, sperm count and failed to illicit any spermatotoxic effect.

High rate of rifampicin resistance of Mycobacterium tuberculosis in the Taif region of Saudi Arabia.

This retrospective study was undertaken to determine the prevalence and pattern of resistance to antituberculosis drugs among patients with sputum-proven pulmonary tuberculosis who were seen in Taif Chest Hospital over 24 months (between June 1986 and May 1988). The overall prevalence was 22.6% and the majority (53%) were resistant to two drugs. Resistance to streptomycin was most frequent (16%) followed by rifampicin (15%). Resistance to isoniazid was surprisingly low (6.5%). 23.3% of the resistant group had previously received antituberculosis drugs as against 15.4% in the sensitive group. There was a significant association between previous therapy and resistance to antituberculosis drugs. Recommendations to reduce the problem of resistance and to improve compliance are discussed.

The effects of charcoal and sorbitol (alone and in combination) on plasma theophylline concentrations after a sustained-release formulation.

1. The effects of charcoal and sorbitol, alone and in combination, were investigated in eight healthy female volunteers who received 600 mg slow-release theophylline (two 300 mg capsules). 2. The area under the plasma concentration time curve to 24 h (AUC0-24) after theophylline alone was significantly greater than after both the charcoal and charcoal plus sorbitol phase. 3. Charcoal and charcoal with sorbitol also significantly reduced the maximum plasma theophylline concentration (Tmax) and time to maximum concentration (Cmax). 4. Sorbitol significantly increased Cmax and shortened Tmax. 5. Although sorbitol did not reduce the adsorptive efficacy of charcoal, its use alone may be deleterious in poisoning with sustained-release theophylline products.

Drug adsorption to charcoals and anionic binding resins.

1. The in-vitro binding of four drugs with differing physiochemical properties to two commercial charcoal preparations and two anionic binding resins was studied at 37 degrees C and pH 7.4. 2. The two charcoal preparations (Carbomix and Medicoal) behaved similarly and adsorbed metoclopramide and antipyrine to a greater degree than warfarin or paracetamol. 3. Cholestyramine had a significantly greater maximum adsorption capacity (K2) for warfarin and significantly lower adsorption capacity for paracetamol and metoclopramide than did the charcoals. 4. Colestipol behaved similarly but also bound metoclopramide to a significantly greater extent than did either cholestyramine or charcoal and antipyrine to a significantly lesser extent than did Carbomix. 5. There appeared to be no consistent relationship between the maximum adsorption capacity of the adsorbents for the drugs tested and the physicochemical properties of those drugs (e.g. basic or acidic structure, pKa or molecular weight).