Drug Interaction Report

ADJUST DOSING INTERVAL: The concomitant use of bone marrow depressants or cytotoxic agents with strontium-89 chloride may result in additive myelosuppression. Bone marrow toxicity is expected following the administration of strontium-89 chloride alone, especially with regards to white blood cells (WBCs) and platelets. The nadir of platelet depression for most patients is about 4 to 16 weeks after a strontium-89 chloride injection. Recovery can be slow and may not be complete.

MANAGEMENT: Concomitant use of strontium-89 chloride and a bone marrow suppressant or cytotoxic agent is not generally recommended. Some authorities advise separating strontium-89 chloride administration from that of a cytotoxic agent by an interval of at least 12 weeks, provided that the patient's hematological parameters are stable and within the normal range. The product labeling for the concomitant myelosuppressive/cytotoxic medication should be consulted for more specific recommendations. Patients should be advised to contact their physician if they develop signs and symptoms of myelosuppression such as pallor, dizziness, fatigue, lethargy, fainting, easy bruising or bleeding, or signs of infection such as fever, chills, sore throat, body aches, and other influenza-like symptoms.

GENERALLY AVOID: Concurrent use of ethanol and phenothiazines may result in additive CNS depression and psychomotor impairment. Also, ethanol may precipitate dystonic reactions in patients who are taking phenothiazines. The two drugs probably act on different sites in the brain, although the exact mechanism of the interaction is not known.

MANAGEMENT: Patients should be advised to avoid alcohol during phenothiazine therapy.