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Page 24 of 33 Berardi et al. J Cancer Metastasis Treat 2019;5:79 I http://dx.doi.org/10.20517/2394-4722.2019.008

insufficiency and serum concentrations of renin and mineralocorticoid should be evaluated to confirm the
diagnosis [149] .

For a correct management of cancer patients with hyperkalemia, it is important to consider presence of
ECG alteration, symptoms, and degree of hyperkalemia.

Hyperkalemia treatment requires first to eliminate all potassium exogenous sources and, when possible,
discontinue treatment with drugs favoring hyperkalemia [Figure 6].

Furthermore, it is important to counteract cardiac effects of hyperkalemia. In the case of enlargement of
QRS complex, intravenous infusion of calcium (e.g., 1fl calcium gluconate 10 mL) and electrocardiographic
monitoring are required.

In the case of severe hyperkalemia and electrocardiographic alterations, immediate treatment should be
set up. To obtain a rapid reduction of serum potassium level, the administration of medications able to
bring potassium in intracellular compartment should be performed [150] . Several treatment options can be
considered:
- Insulin (e.g., 10 units of fast insulin associated to 500 mL of glucose solution at 10% or 250 mL of glucose
solution infused in 30-60 min).
- Sodium bicarbonate (e.g., Sodium bicarbonate 1 mEq/kg in 10-20 min), which should be avoided in
patients with heart or renal failure, because it might worsen fluid retention.
- Beta-2 agonists (e.g., 10-20 mg salbutamol to inhale in 10 min), which should be avoided in patients with
ischemic cardiomyopathy or cardiac arrhythmias.

Although these treatment options are effective in rapidly correcting hyperkalemia, the redistribution of
potassium into the intracellular compartment is temporary. Furthermore, sodium bicarbonate and beta-2
agonists should be used as adjuvant treatments, in combination with other therapies [150] .

Patients with moderate and asymptomatic hyperkalemia do not require an immediate serum potassium
reduction and can be treated with medications that remove potassium excess but require several hours [151] .
Several treatment options can be considered. Cation exchange resins (Kayexalate) should be preferred.
However, due to high sodium content, they have to be used with caution in presence of heart or renal
failure, to avoid fluid retention.

Abundant intravenous hydration associated with diuretics (furosemide 40-80 mg) can be considered a
valid treatment option; however, it should be avoided in patients with heart failure for fluid overload
risk. Furthermore, diuretics have been demonstrated to control serum potassium level only in chronic
hyperkalemia, and they should be reserved only for the management of these forms. Dialysis can be
considered in the case of renal failure when resins and diuretics fail [152] .

In patients with severe hyperkalemia, plasma potassium levels and ECG should be frequently monitored
during treatment (every 1-6 h) until symptoms’ resolution, followed by monitoring every 4-12 h until
normokalemia achievement [153] .

MAGNESIUM
Magnesium is an important intracellular cation, second to potassium for prevalence. It acts as an essential
cofactor for several intracellular enzymes involved in cells replication and energy metabolism processes,
including phosphate transfer. Furthermore, it has a crucial role in muscular contractility and neuronal
transmission [154] .