Tandem Diabetes announces expanded recall of insulin cartridges Tandem Diabetes Care announced that it is expanding a voluntary recall of specific lots of insulin cartridges that are used with the t:slim Insulin Pump. The affected cartridges may be at risk for leaking. This could potentially result in the device delivering too much or too little insulin, which can lead to a serious adverse event, the company said. Tandem said, "Based on the periods during which the affected lots were shipped, the Company believes a significant number of the affected cartridges have already been used and therefore will not be exchanged. In addition to the expenses associated with replacing affected cartridges, the Company may also incur additional logistical shipping fees and other recall coordination costs. Tandem is also in the process of evaluating additional cartridges still in the Company's internal inventory to determine whether they will be usable, and may incur expenses with those that are unusable."