Paricalcitol and Zoledronate in Treating Patients With Relapsed or Refractory Multiple Myeloma or Other Plasma Cell Disorders

DISEASE CHARACTERISTICS: * Diagnosis of relapsed or refractory multiple myeloma (MM) or other plasma cell disorder (PCD) * At least one previous treatment for MM or PCD required PATIENT CHARACTERISTICS: Performance status * ECOG 0-2 OR * Karnofsky 60-100% Life expectancy * At least 3 months Hematopoietic * Not specified Hepatic * Not specified Renal * Calcium ≤ 10.5 mg/dL * No renal stone formation within the past 5 years for patients who have had curative therapy for a condition associated with the risk of stones (e.g., hyperparathyroidism, bladder dysfunction, obstructive uropathy) OR had a single episode of confirmed urolithiasis * No calculi in urinary tract confirmed by renal ultrasonography, kidney, ureter, and bladder (KUB) x-ray, or other imaging modality Cardiovascular * No symptomatic congestive heart failure * No unstable angina pectoris * No uncontrolled cardiac arrhythmia Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during study and for 3 months after study completion * No osteonecrosis of the jaw * No history of allergic reaction attributed to compounds of similar chemical or biological composition of calcitriol, paricalcitol, or zoledronate * No uncontrolled intercurrent illness that would preclude study compliance * No ongoing or active infection * No psychiatric illness or social situation that may preclude study compliance PRIOR CONCURRENT THERAPY: Chemotherapy * More than 4 weeks since prior chemotherapy Endocrine * More than 4 weeks since prior high-dose steroids Other * No other concurrent investigational agents or therapies for multiple myeloma or plasma cell disorders * No concurrent digoxin