Cubist Pharmaceuticals Inc. is warning healthcare providers not to use ReadyMED elastomeric infusion pumps with Cubicin. According to the company, a potentially significant impurity has been found in reconstituted Cubicin stored in ReadyMED pumps.
Cubicin is used intravenously to treat bacterial infections of the skin and underlying tissues. The new safety information applies only to Cubicin (daptomycin for injection) that is compatible with the ReadyMED elastomeric infusion pumps manufactured by Cardinal Health, Inc.
According to Cubist, laboratory investigations conducted by Cubist have examined the stability of daptomycin, reconstituted in 0.9% sodium chloride for injection USP and stored in ReadyMED and Eclipse (I-Flow Corporation) elastomeric infusion pumps, at a concentration of 20 mg/mL for at least 10 days under refrigerated (5ºC) conditions. Results demonstrated acceptable Cubicin stability up to and including the 10th day in the control samples as well as samples from both pumps. However, the chemical 2-mercaptobenzothiazole (MBT) was detected in samples from the ReadyMED pumps. MBT was not detected in samples from the Eclipse pumps or control samples.
MBT is used in the manufacture of rubber as an accelerant in the vulcanization process. Human, non-occupational environmental exposure to low levels of MBT can occur through direct contact with rubber products and through consumption of water in contact with rubber plumbing products. MBT has been reported to leach from rubber stoppers and syringe components into medicinal products in the past. Skin exposure to MBT has been associated with dermal sensitization, and chronic administration of MBT to laboratory rodents has been associated with an increased risk of certain tumors.
Cubist said it has not evaluated the stability of reconstituted Cubicin in elastomeric infusion pumps other than ReadyMED and Eclipse. No MBT has been identified in reconstituted Cubicin in other standard types of infusion systems that have been tested.