It binds to ergosterol in the fungal cell membrane forming large channels through which cellular contents leak leading to cell death. Toxicity results from the binding of ampho B molecules to cholesterol in the host's cell membrane. The renal epithelial cells are particularly susceptible to this adverse effect.
Candida cystitis is treated via bladder irrigation.
The kinetics of ampho B is complicated and not fully elucidated. However, liver disease does not appear to affect its serum level. It is not absorbed by the GI, and it is not removed by hemodialysis. Typically, this reaction starts within the first 2 hrs of infusion and may last for 2 - 4 hrs. This reaction may be mediated by the release of TNF and IL-1 from macrophages.