Calcium Gluconate and Magnesium Sulfate in Preventing Neurotoxicity Caused By Oxaliplatin in Patients Receiving Combination Chemotherapy for Stage II, Stage III, or Stage IV Colorectal Cancer That Has Been Completely Removed By Surgery

DISEASE CHARACTERISTICS:

* Histologically confirmed adenocarcinoma of the colon or rectum

  * Stage II disease
  * Stage III disease
  * Stage IV disease (completely resected with no evidence of residual tumor)
* Must have undergone curative resection for stage II or III disease
* Scheduled to receive 6 months of adjuvant treatment with either of the following FOLFOX chemotherapy regimens:

  * FOLFOX4, comprising leucovorin calcium, fluorouracil, and oxaliplatin (2-week course)
  * Modified FOLFOX6, comprising high-dose leucovorin calcium, high-dose fluorouracil, and oxaliplatin (2-week course)

PATIENT CHARACTERISTICS:

* Absolute neutrophil count ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Hemoglobin ≥ 10 g/dL
* WBC ≥ 3,000/mm\^3
* Bilirubin ≤ 1.5 times upper limit of normal (ULN)
* Creatinine ≤ 1.5 times ULN
* Calcium normal
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* No pre-existing peripheral neuropathy of any grade
* No hypercalcemia
* No concurrent heart block or a history of heart block
* No other medical condition that, in the opinion of the treating physician, would make this protocol unreasonably hazardous for the patient
* No family history of a genetic/familial neuropathy

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* No prior treatment with neurotoxic chemotherapy such as oxaliplatin, cisplatin, taxanes, or vinca alkaloids
* Concurrent use of bevacizumab or cetuximab in combination with FOLFOX as part of a clinical trial or clinical practice are allowed
* No concurrent digitalis medication
* No concurrent digoxin
* No concurrent treatment with anticonvulsants such as carbamazepine, phenytoin, or valproic acid
* No other concurrent neurotropic agents such as gabapentin