FOLFOX regimen induced severe hypokalaemia with hypocalcaemia and hypomagnesaemia.

FOLFOX regimen is a chemotherapy regimen commonly used to treat colorectal cancers and other gastrointestinal malignancies. It comprises a combination of drugs, including leucovorin, 5-fluorouracil and oxaliplatin. Hypokalaemia can be a potential adverse drug reaction to the FOLFOX regimen, along with other haematological or metabolic adverse effects. Causes for hypokalaemia include chemotherapy-induced diarrhoea, nausea, vomiting and increased renal loss of potassium. The oxaliplatin used in the FOLFOX regimen is often associated with hypokalaemia due to intracellular shift, secondary to using 5% dextrose for infusion. Therefore, close monitoring of electrolyte levels, including potassium, is essential during chemotherapy treatment. Patients may require supplementation with potassium, either orally or intravenously, to maintain adequate levels and prevent complications. Additionally, managing diarrhoea, nausea and vomiting can help minimise potassium loss during chemotherapy. This case describes a patient who developed severe hypokalaemia (1.4 mmol/L) associated with the use of the FOLFOX regimen without any cardiac arrhythmia.