How to Make the Best Use of Our Services

• What information to send with your sample
• Required formats for samples
• Guidelines for antifungal drug monitoring
• Interpretation of assay results
   

 

What information to send with your sample

Please use the following request forms as appropriate for submitting isolates and clinical samples:

• Y1 Mycology identification/susceptibility testing form (PDF, 312 KB)   when referring isolates of yeast or mould for identification and/or susceptibility testing
• Y2 Diagnostic mycology testing form (PDF, 320 KB) when referring clinical samples for diagnostic mycology testing
   

Required formats for samples  

All samples should be securely packaged conforming to current postal regulations.

Cultures for identification and susceptibility testing

• Please send pure cultures on slopes rather than plates.
• For Hazard Group 3 pathogens please give the laboratory advanced warning by telephone that a culture is about to be submitted. Only send slopes of cultures and do not wait for the organisms to start to sporulate.

Serological tests

• For serological tests please supply 1 - 2 ml of serum (do not send whole blood).
• Please ensure all high risk samples are clearly labelled.

Antifungal assays

• Please contact the laboratory before submitting samples for amphotericin B or fluconazole assays, as their measurement is not often indicated
• Please supply 1-2 ml serum taken at the appropriate times and labelled accordingly.

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Guidelines for antifungal drug monitoring

Oral flucytosine	pre-dose and 2 hours post-dose
IV flucytosine	pre-dose and 30 mins. post-dose
Oral or IV itraconazole	pre-dose after 7 days
Oral posaconazole	pre-dose after 5 days
Oral voriconazole	pre-dose after 5 days
IV voriconazole	pre-dose after 5 days
Amphotericin	1 – 2 hours post-dose
Oral fluconazole	2 hours post-dose
IV fluconazole	30 mins. post-dose

  Please ensure all high risk samples are clearly labelled.

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Interpretation of assay results 

FLUCYTOSINE

Serum samples should be taken just before a dose of flucytosine, and 2 hours after an oral dose or 30 min after an intravenous dose. The dose and interval should be adjusted in order to produce peak serum concentrations of about 70-90 mg/L and trough concentrations of 20-40 mg/L. Levels >100 mg/L are toxic.

ITRACONAZOLE

The trough level should be maintained above 0.5 mg/L.
Less than 0.5mg/L is a low concentration.
There may be toxicity issues at higher concentrations (>4 mg/L). Liver function tests should be monitored during prolonged courses.

POSACONAZOLE

The absorption and metabolism of posaconazole will vary from patient to patient and although there are no established recommendations, better therapeutic responses have been documented in patients with levels above 0.7 mg/L.

VORICONAZOLE 

The absorption and metabolism of voriconazole will vary from patient to patient and although there are no established recommendations, better therapeutic responses have been documented in patients with levels above 1.3 mg/L.
Levels above 6.0 mg/L are more likely to lead to liver toxicity and levels above 10.0 mg/L should be avoided.

AMPHOTERICIN B

Monitoring of blood concentrations of amphotericin B during treatment is seldom indicated. The optimum serum concentrations of the drug for particular fungal infections have not been determined. Toxicity is assessed by monitoring renal function. Although amphotericin B is nephrotoxic, high blood concentrations do not lead to greater impairment of renal function, nor does renal failure result in higher blood concentrations. 

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Last reviewed: 11 January 2012