Amphotericin B (deoxycholate & lipid forms)

What is this medication for?

• Serious systemic mycoses: blastomycosis, histoplasmosis, cryptococcosis, coccidioidomycosis, aspergillosis, resistant filamentous fungi/pythiosis

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Sodium loading (5 mL/kg NS pre/post) is cheap renal protection; mannitol works but may cut efficacy (blastomycosis) and cost more.
• Lipid formulations changed the risk math: 8–10× less kidney damage → higher cumulative doses reachable for resistant infections, at much higher cost.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Hypokalemia, hypomagnesemia, distal RTA (Electrolyte-wasting)
• Infusion reactions: fever, vomiting, phlebitis, arrhythmias (Pretreat NSAID/low-dose steroid)
• Non-regenerative low red blood cell counts, calcinosis cutis (Chronic therapy)

Worth a phone call to your veterinarian

• Nephrotoxicity (vasoconstriction ↓GFR + tubular toxicity) (Most dogs show some degree; usually reversible but may take months)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Hypersensitivity (unless life-threatening infection with no alternative)
• has or has had: Not contraindicated in renal disease (disease severity) — but cautious monitoring mandatory; rehydrate sodium-depleted patients BEFORE dosing

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Aminoglycosides, other kidney damage
  • Diuretics
  • Flucytosine
  • Azoles

Storage and handling

Dilute ONLY in D5W (never saline — precipitation); protect from light; central/peripheral vein per formulation. Lipid products per label. Pre-hydrate and sodium-load: 5 mL/kg NS split before/after each dose.

Good to know

• Dosing is cumulative-total based, not course-length based — track the running total (9–12 mg/kg standard; higher for resistant fungi with lipid forms).
• Sodium loading (5 mL/kg NS pre/post) is cheap renal protection; mannitol works but may cut efficacy (blastomycosis) and cost more.
• The cat dose is HALF the dog dose (0.25 vs 0.5 mg/kg) — feline kidney damage threshold is lower.
• Lipid formulations changed the risk math: 8–10× less kidney damage → higher cumulative doses reachable for resistant infections, at much higher cost.