From the FDA Drug Label
Rapid intravenous infusion has been associated with hypotension, hypokalemia, arrhythmias, and shock and should, therefore, be avoided Corticosteroids and Corticotropin (ACTH): may potentiate amphotericin B-induced hypokalemia which may predispose the patient to cardiac dysfunction. Digitalis glycosides: amphotericin B-induced hypokalemia may potentiate digitalis toxicity. Skeletal muscle relaxants: amphotericin B-induced hypokalemia may enhance the curariform effect of skeletal muscle relaxants (e.g., tubocurarine).
Antifungal medications, such as amphotericin B, can affect potassium levels by causing hypokalemia (low potassium levels). This can occur with rapid intravenous infusion and can be potentiated by concomitant use of corticosteroids, corticotropin, and other medications. It is essential to monitor serum electrolytes, particularly potassium, and cardiac function when using amphotericin B, especially in patients with pre-existing cardiac conditions or those taking digitalis glycosides or skeletal muscle relaxants 1.
On the other hand, sodium polystyrene sulfonate is used to treat hyperkalemia (high potassium levels) by increasing fecal potassium excretion through binding of potassium in the gastrointestinal tract, which can lead to hypokalemia if not monitored properly 2.
Key points:
- Antifungal medications like amphotericin B can cause hypokalemia.
- Sodium polystyrene sulfonate can cause hypokalemia by increasing fecal potassium excretion.
- Monitoring of serum electrolytes, particularly potassium, is crucial when using these medications.
From the Research
Antifungal medications, particularly Amphotericin B, can significantly affect potassium levels, causing hypokalemia in up to 80% of patients, and therefore, patients taking Amphotericin B should have their potassium levels monitored regularly and consider early potassium supplementation to prevent severe hypokalemia. The occurrence of hypokalemia is a significant concern in patients receiving antifungal medications, especially Amphotericin B, as it can lead to increased morbidity and mortality. According to a study published in 2018 3, liposomal amphotericin B (L-AMB) can cause renal dysfunction and serum potassium abnormality, with an overall occurrence rate of hypokalemia of 76.6%. Another study published in 2018 4 found that starting potassium supplementation within 2 days from the start of L-AMB administration was an independent factor reducing the risk of L-AMB-induced hypokalemia. However, a more recent study published in 2021 5 found that potassium supplementation was not associated with any stage of acute kidney injury in patients with hypokalemia who were administered L-AMB. It is essential to note that the mechanism of hypokalemia induced by Amphotericin B involves damage to cell membranes in the distal tubule, creating leaky channels that prevent proper potassium reabsorption and regulation. Some studies suggest that spironolactone may be useful in reducing potassium requirements and preventing hypokalemia in patients on AmB treatment 6. In terms of specific antifungal medications, azole antifungals like fluconazole, itraconazole, and voriconazole generally have less impact on potassium levels, though they can occasionally cause electrolyte disturbances, while echinocandins (caspofungin, micafungin, anidulafungin) rarely affect potassium balance. Key points to consider when managing patients on antifungal medications include:
- Monitoring potassium levels regularly, typically 2-3 times weekly during treatment
- Considering early potassium supplementation to prevent severe hypokalemia
- Being aware of the potential for hypokalemia and taking steps to mitigate it
- Using liposomal formulations of Amphotericin B, which cause less nephrotoxicity and potassium wasting than conventional formulations.