Considerations for laxatives in terms of their interactions with other drugs.

Laxatives represent the main treatment for constipated subjects since ancient times [1], are among the most frequently used drugs worldwide, and impose a substantial economic burden on both patients and health-care systems [2]. Although the use of laxatives is generally perceived as safe in the public opinion, an important issue to take into account is that constipation increases in frequency with age and that aged subjects are those with the major consumption of drugs. This increases the risk of potentially harmful pharmacologic interactions. A significant problem in evaluating this aspect of laxatives is due to the fact that many (probably, most) constipated patients often escape the physicians’ prescription and self treat their symptoms by means of over the counter (OTC) products [3]. Of note, these products are frequently not disclosed to the caring physicians probably because OTCs are not considered as actual drugs, and their use is often strictly linked to person to person (friends, neighbors, etc.) suggestions or pharmacist’s advice. It is also extremely important to remember that many OTC products are represented by herbal formulations (often composed of different and heterogeneous substances, employed for multiple dissimilar pathological conditions) and that these may interact with laxatives [4]. Thus, there is a concrete possibility that, especially in elderly subjects and/or in those treated with multiple drug regimens, the widespread use of laxatives (including the OTC ones) could cause potential interactions with other drugs. Unfortunately, this aspect has been almost neglected by researchers. Therefore, the literature evidence on this topic is relatively scarce, and these interactions are rarely detailed or are based on single-case reports [5].