Calcium Gluconate and Magnesium Sulfate in Preventing Neurotoxicity in Patients With Colon Cancer or Rectal Cancer Receiving Oxaliplatin-Based Combination Chemotherapy

DISEASE CHARACTERISTICS:

* Histologically confirmed adenocarcinoma of the colon or rectum
* Has undergone curative resection and is considered to have stage II or III disease or completely resected stage IV disease with no evidence of residual tumor
* Scheduled to receive 6 months of oxaliplatin-based adjuvant chemotherapy with 85 mg/m\^2 oxaliplatin every 2 weeks (this includes, for instance, FOLFOX4 or modified FOLFOX6)

  * Patients receiving bevacizumab or cetuximab in combination with FOLFOX as part of a clinical trial or clinical practice are eligible

PATIENT CHARACTERISTICS:

* ECOG performance status 0-2
* WBC ≥ 3,000/mm\^3
* ANC ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Hemoglobin ≥ 10.0 g/dL
* Total bilirubin ≤ 1.5 times upper limit of normal (ULN)
* Serum creatinine ≤ 1.5 times ULN
* Serum calcium ≤ 1.2 times ULN
* Serum magnesium ≤ 1.2 times ULN
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* Able to complete questionnaires (alone or with assistance)
* Able to comply with study treatment
* Willing to return to enrolling institution for follow-up
* Willing to provide blood sample for research purposes
* No pre-existing peripheral neuropathy of any grade
* No family history of a genetic/familial neuropathy
* No second or third degree AV heart block or a history of second or third degree heart block

  * Bundle branch blocks are allowed.
* No other medical conditions that, in the opinion of the treating physician, would make this protocol unreasonably hazardous for the patient

PRIOR CONCURRENT THERAPY:

* See Disease Characteristics
* Central venous access line present, or scheduled to have a central line placed before starting chemotherapy and study treatment
* No prior treatment with neurotoxic chemotherapy (e.g., oxaliplatin, cisplatin, taxanes, or vinca alkaloids)
* No concurrent digitalis medication
* No concurrent treatment with the anticonvulsants carbamazepine (e.g., Tegretol®), phenytoin (e.g., Dilantin®), valproic acid (e.g., Depakene®), gabapentin (Neurontin®), or pregabalin (Lyrica®)
* No concurrent neurotropic agents, including venlafaxine (Effexor), desvenlafaxine (Pristiq®), milnacipran (Savella®), or duloxetine (Cymbalta)
* No concurrent tricyclic antidepressants (such as amitryptilline), or any other agent specifically being given to prevent or treat neuropathy
* No concurrent drugs given as a neuroprotectant