Neuvonen P J, Kivistö K T
Department of Clinical Pharmacology, University of Helsinki, Finland.
Clin Pharmacokinet. 1994 Aug;27(2):120-8. doi: 10.2165/00003088-199427020-00004.
Antacids are widely used for many disorders. The potential of antacids to interact with other concomitantly ingested drugs is well recognised. These interactions usually result in reduced or delayed absorption of the affected drug. However, this is not always the case. In contrast to aluminium hydroxide, magnesium hydroxide and sodium bicarbonate can enhance the absorption of some drugs. For example, magnesium hydroxide can increase the rate and sometimes even the extent of absorption of certain nonsteroidal anti-inflammatory drugs (e.g. tolfenamic acid, mefenamic acid and ibuprofen), sulphonylurea antidiabetic agents [e.g. glipizide, glibenclamide (glyburide) and tolbutamide] and the oral anticoagulant dicoumarol (bishydroxycoumarin). These weakly acidic drugs are nonionised at gastric pH, but are sparingly water soluble. Elevation of the gastric pH by administration of magnesium hydroxide or sodium bicarbonate increases the solubility and absorption of such sparingly water soluble agents. Chelate formation may be involved in the increased absorption of dicoumarol by magnesium hydroxide. In combination antacids containing both aluminium hydroxide and magnesium hydroxide, the absorption enhancing effect of magnesium hydroxide seems to be counterbalanced by the opposing effects of aluminium hydroxide. The clinical significance of increased drug absorption is not clear. However, accelerated and enhanced absorption of analgesic drugs may be beneficial when rapid pain relief is desired. In contrast, an unexpectedly increased hypoglycaemic or anticoagulant effect may be potentially dangerous. Therefore, a knowledge of the potential effect of antacids on the absorption of other drugs is clinically important.
抗酸剂被广泛用于多种病症。抗酸剂与其他同时摄入的药物相互作用的可能性已得到充分认识。这些相互作用通常会导致受影响药物的吸收减少或延迟。然而，情况并非总是如此。与氢氧化铝不同，氢氧化镁和碳酸氢钠可增强某些药物的吸收。例如，氢氧化镁可提高某些非甾体抗炎药（如托芬那酸、甲芬那酸和布洛芬）、磺酰脲类抗糖尿病药物[如格列吡嗪、格列本脲（优降糖）和甲苯磺丁脲]以及口服抗凝剂双香豆素（双羟基香豆素）的吸收速率，有时甚至能提高吸收程度。这些弱酸性药物在胃内pH值条件下呈非离子化状态，但水溶性较差。服用氢氧化镁或碳酸氢钠使胃内pH值升高，可增加此类水溶性差的药物的溶解度和吸收。氢氧化镁使双香豆素吸收增加可能与螯合物形成有关。在同时含有氢氧化铝和氢氧化镁的复方抗酸剂中，氢氧化镁的吸收增强作用似乎被氢氧化铝的相反作用所抵消。药物吸收增加的临床意义尚不清楚。然而，当需要快速缓解疼痛时，镇痛药吸收加速和增强可能是有益的。相比之下，低血糖或抗凝作用意外增强可能具有潜在危险性。因此，了解抗酸剂对其他药物吸收的潜在影响在临床上具有重要意义。
