Han, C.H., Khwaounjoo, P., Kilfoyle, D.H., Hill, A., & McKeage, M.J. (2013). Phase I drug-interaction study of effects of calcium and magnesium infusions on oxaliplatin pharmacokinetics and acute neurotoxicity in colorectal cancer patients. BMC Cancer, 13, 495.

To investigate the effects of calcium and magnesium infusions on oxaliplatin pharmacokinetics and neurotoxicity

Patients were randomized to receive either 1 g calcium and 1 g magnesium IV or placebo 15 minutes before and after a two-hour oxaliplatin infusion on cycle 1, then crossed over to the other intervention on cycle 2. Blood samples were obtained at multiple time points during and after the oxaliplatin infusion for pharmacokinetic analysis. Other study measures were obtained on day 2 and at the end of treatment cycles 1 and 2.

• N = 19
• MEDIAN AGE = 62 years
• AGE RANGE = 31–77 years
• MALES: 60%, FEMALES: 40%
• KEY DISEASE CHARACTERISTICS: Colorectal adenocarcinoma—95% had stage 3 or 4 disease; patients were receiving either a XELOX or modified FOLFOX6—all received the same dosage level of oxaliplatin
• OTHER KEY SAMPLE CHARACTERISTICS: Two patients had diabetes mellitus.

• SITE: Single site 
• SETTING TYPE: Outpatient 
• LOCATION: New Zealand

• PHASE OF CARE: Active antitumor treatment

• Double-blind, placebo-controlled, crossover trial

• EMG with severity score calculation from severity of hyperexcitability and number of muscles affected—four-point severity score
• Patient questionnaire of presence or absence of acute neurotoxicity symptoms

No evidence existed of a pharmacokinetic interaction between calcium and magnesium infusions and oxaliplatin. Most patients demonstrated EMG changes about 24 hours after oxaliplatin. No differences were seen between the experimental and control conditions.

Findings did not show a benefit of calcium and magnesium infusions for prevention of neurotoxicity symptoms from oxaliplatin.

• Small sample (less than 100)

Findings demonstrate that calcium and magnesium infusions did not have a preventive effect on the development of neuropathy symptoms in patients receiving oxaliplatin. Findings also showed that EMG changes happened within 24 hours of treatment. Nurses need to be aware that neuropathic symptoms can develop very quickly and need to assess for such changes early and on a routine basis to identify patients who may need dose reduction or other interventions.