Drug Interaction Report

MONITOR: In multiple myeloma patients, the risk of renal dysfunction may be increased when intravenous bisphosphonates are used in combination with thalidomide. The mechanism of interaction has not been described.

MANAGEMENT: Caution is advised if pamidronate, zoledronic acid, or other intravenous formulations of bisphosphonates must be used in multiple myeloma patients who are receiving treatment with thalidomide. Renal function and serum electrolytes should be monitored. Product labelings for pamidronate and zoledronic acid recommend that single doses not exceed 90 mg and 4 mg, respectively, and the duration of infusion not less than 2 hours and 15 minutes, respectively. Patients should have serum creatinine assessed prior to each treatment, and treatment should be withheld for renal deterioration. In those treated for bone metastases, treatment should not be resumed until renal function returns to baseline.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.