Guggenbichler J P
Padiatr Padol. 1982;17(3):565-84.
Besides the considerable differences in the intestinal absorption of the different antibiotic classes as described in part I of this paper galenic preparations and the administration in form of a capsule -- tablet or sirup play a major role too. The particle size of antimicrobial drugs in sirup form has to be carefully selected. It should not be too small to prevent a rapid decay of the substance by gastric acid; if it is too large the dissolution of the substance is not fast enough for maximal absorption in the upper intestinal tract. Enteric coating, soluble binders, the dissolution time of a tablet are other important variables in the absorption of orally administered antibiotics. The most important influence on the resorption of orally administered antibiotics comes from the patient. Individual variations in the absorption are exceptionally high with amoxycillin. Different age groups show considerable variations in intestinal absorption which can amount to an extent of a two to threefold increase or decrease over the mean. Simultaneous administration of food or drugs have significant influences on the absorption of certain antibiotics. The pharmacokinetic investigation and bioavailability studies are done on healthy young adults. Diseases of the intestinal tract like acute diarrhea or malabsorption syndromes influence the absorption of orally administered antibiotics to a considerable extent which even renders some drugs completely ineffective. In cystic fibrosis the enteral absorption is retarded and pharmakokinetic parameters sizably altered.
除了本文第一部分所述的不同抗生素类别在肠道吸收方面存在显著差异外,药剂制剂以及胶囊、片剂或糖浆形式的给药方式也起着重要作用。糖浆形式抗菌药物的粒径必须仔细选择。粒径不宜过小,以免药物被胃酸迅速分解;如果粒径过大,药物溶解速度不够快,无法在上消化道实现最大吸收。肠溶包衣、可溶性粘合剂、片剂的溶解时间是口服抗生素吸收过程中的其他重要变量。口服抗生素吸收最重要的影响因素来自患者。阿莫西林的个体吸收差异非常大。不同年龄组在肠道吸收方面存在显著差异,与平均值相比,吸收程度可能会有两到三倍的增加或减少。同时服用食物或药物对某些抗生素的吸收有显著影响。药代动力学研究和生物利用度研究是在健康的年轻成年人身上进行的。肠道疾病,如急性腹泻或吸收不良综合征,会在很大程度上影响口服抗生素的吸收,甚至会使某些药物完全失效。在囊性纤维化患者中,肠道吸收会延迟,药代动力学参数也会有显著改变。