AMPHOTEC
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMPHOTEC (AMPHOTEC).
Amphotericin B binds to ergosterol in fungal cell membranes, forming pores that disrupt membrane integrity, leading to leakage of intracellular contents and cell death.
| Metabolism | Metabolized minimally, if at all; elimination is primarily via unchanged drug excretion in urine and bile over a prolonged period. |
| Excretion | Biliary/fecal: ~90% unchanged; renal: <10% (mainly as metabolite). |
| Half-life | Terminal half-life: 24-48 hours (up to 7 days in hepatic impairment). Long half-life allows once-daily dosing. |
| Protein binding | >95% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 4.0 L/kg (large, indicates extensive tissue binding, especially in liver, spleen, and lungs). |
| Bioavailability | Not applicable (IV only); if oral, <5% (due to poor absorption and first-pass metabolism). |
| Onset of Action | Intravenous: 24-48 hours (antifungal effect); Intrathecal: immediate (for cryptococcal meningitis, CSF levels detectable within hours). |
| Duration of Action | Antifungal effect persists for 2-4 weeks after discontinuation due to long half-life and tissue accumulation. |
Initial dose: 0.5 mg/kg intravenously once daily, titrated as tolerated to 5 mg/kg once daily.
| Dosage form | INJECTABLE, LIPID COMPLEX |
| Renal impairment | No dose adjustment required for renal impairment; however, monitor renal function closely during therapy. |
| Liver impairment | No specific dose adjustment recommended; use with caution in severe hepatic impairment. |
| Pediatric use | 5 mg/kg intravenously once daily; safety and efficacy not established in neonates. |
| Geriatric use | No specific dose adjustment; monitor renal function and electrolyte levels due to age-related decline in renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMPHOTEC (AMPHOTEC).
| Breastfeeding | Amphotericin B is excreted into breast milk in low concentrations. The M/P ratio is unknown. It is considered compatible with breastfeeding because of poor oral bioavailability; however, caution is advised, and monitoring for infant diarrhea or thrush is recommended. |
| Teratogenic Risk | Amphotericin B (AMPHOTEC) is classified as category B. Animal studies have not demonstrated fetal harm, but there are no adequate human studies in pregnant women. Inadvertent use during the first trimester is not associated with a significant increase in congenital anomalies. During the second and third trimesters, there is no evidence of fetal toxicity, although the drug should be used only if clearly needed due to maternal systemic fungal infection. |
■ FDA Black Box Warning
This drug should be used primarily for treatment of patients with progressive, potentially life-threatening fungal infections; it is not intended for treatment of non-invasive fungal infections (e.g., oral thrush, vaginal candidiasis) in patients with normal neutrophil counts.
| Serious Effects |
["Hypersensitivity to amphotericin B or any component of the formulation (unless condition is life-threatening and amenable only to amphotericin therapy)."]
| Precautions | ["Nephrotoxicity: monitor renal function closely; risk increased with concurrent nephrotoxic drugs.","Infusion-related reactions: fever, chills, rigors, hypotension, dyspnea; premedicate as needed.","Electrolyte abnormalities: hypokalemia, hypomagnesemia; monitor levels and replace.","Hepatotoxicity: monitor liver function tests.","Cardiotoxicity: arrhythmias, especially with rapid infusion or hypokalemia.","Pulmonary toxicity: acute pulmonary edema (rare), especially in patients with low ejection fraction."] |
| Food/Dietary | No specific food interactions. Ensure adequate hydration and electrolyte intake as directed. Avoid grapefruit juice as it may alter drug metabolism. |
Loading safety data…
| Fetal Monitoring | Monitor renal function (serum creatinine, BUN), electrolytes (potassium, magnesium) and hepatic function in both mother and fetus. Assess for infusion-related reactions (fever, chills, hypotension). Monitor for signs of fetal distress or growth restriction via ultrasound if prolonged therapy. |
| Fertility Effects | No adverse effects on fertility have been reported in animal studies. Human data are lacking. Amphotericin B does not appear to impair spermatogenesis or oogenesis based on limited evidence. |
| Clinical Pearls | Amphotec (amphotericin B liposomal) is the preferred formulation for invasive fungal infections due to reduced nephrotoxicity compared to deoxycholate. Monitor for infusion-related reactions (fever, rigors, hypotension) and premedicate with acetaminophen, diphenhydramine, and hydrocortisone. Requires baseline and serial renal function, electrolytes (especially potassium, magnesium), and liver function tests. Do not use with other nephrotoxic drugs if possible. Electrolyte repletion is critical. |
| Patient Advice | This medication treats serious fungal infections and is given intravenously in a hospital setting. · You may experience fever, chills, or shaking during the infusion; these can be managed with premedications. · Kidney function and blood electrolyte levels will be monitored regularly. · Report any signs of allergic reaction (rash, itching, difficulty breathing) or symptoms of electrolyte imbalance (muscle cramps, weakness, irregular heartbeat). · Avoid taking other medications that can harm the kidneys (e.g., certain antibiotics, NSAIDs) without consulting your doctor. |