For Microbiology approval / consultant use only
Invasive fungal infection is a
serious, often fatal, condition in the immunocompromised patient.
Amphotericin B remains the mainstay of treatment but its
administration is hampered by poor patient tolerance and by its renal toxicity.
The diagnosis of
systemic and/or invasive mycosis has been microbiologically confirmed
and discussed with a Consultant Microbiologist / Mycologist.
Conventional
amphotericin should be used in patients with normal renal function.
In the following circumstances a lipid-based formulation of amphotericin should be prescribed:
1.The patient has either
failed to respond after >5 days treatment on conventional
amphotericin B at an appropriate dose
2.The patient shows severe
systemic side effects when treated with conventional amphotericin B
3.The patient shows a marked
degree of renal impairment (<30ml/min) - or develops renal
impairment requiring
discontinuation
of conventional amphotericin B
4.The patient is being
treated with other nephrotoxic agents and therefore at increased risk
of nephrotoxicity from
conventional
amphotericin B
Transplant patients taking ciclosporin should only receive lipid-based formulations of amphotericin
Conventional amphotericin B (Fungizone)
Initial dose = 0.25mg/kg (Dose
range 0.25-1mg/kg. May be up to 1.5mg/kg on advice from consultant
mycologist / microbiologist)
Round the dose to
the nearest 10mg
Amphotericin
should ONLY be diluted with glucose 5% - dilute to a concentration of
10mg per 100ml (this is the same as 0.1mg/ml) for infusion
Infuse 10ml ONLY (1mg) over 10 minutes as a test dose. Observe the patient for 30 minutes, if the patient has no reaction the remainder of the dose can be infused over 2-6 hours
Lipid-based amphotericin B formulations
NOTE
There are two lipid-based
formulations of amphotericin available. The recommended daily dose
for these is different. Prescribe as the brand name and check the
correct dose.
AMBISOME is a liposomal preparation of amphotericin.
ABELCET (Amphotericin B Lipid Complex) is a complex of Amphotericin B with phospholipids, which forms a ribbon-like structure
Note the different concentrations for infusion
|
AMBISOME |
ABELCET |
|
|
USUAL CONCENTRATION |
0.2-2mg/ml |
1mg/ml |
|
MAXIMUM CONCENTRATION |
2mg/ml |
2mg/ml |
|
MANUFACTURER'S DOSAGE (mg/kg/day) |
3 |
5 |
|
LENGTH OF INFUSION (HOURS) |
½ - 1 |
2 |
Doses above those recommended here should ONLY be prescribed on the advice of a consultant mycologist.
Round the dose to the nearest 50mg
Amphotericin
should ONLY be diluted with glucose 5% - dilute to the specified concentration
Infuse a volume equivalent to 1mg (1ml for a 1mg/ml solution) over 10 minutes as a test dose. Observe the patient for 30 minutes, if the patient has no reaction the remainder of the dose can be infused over the specified time period.
Additional advice
For all formulations of amphotericin.
Keep the patient well hydrated.
Administer 500ml to 1L of normal saline before each infusion.
Remember to flush the line with glucose before the amphotericin
infusion is given.
Give amiloride
5mg BD orally whilst on the infusion
Check U&Es
and K+ daily for the first week of treatment and then three times a
week thereafter if remain stable.
Check magnesium levels once a week.
Important
A daily review of the patient's
proposed duration of treatment should take place.