Categories

Recommendation for the Most Effective Itraconazole Treatment of Serious Fungal Infections

Recommendation for the Most Effective Itraconazole Treatment of Serious Fungal Infections

FINDINGS FROM A RECENT CLINICAL STUDY PERFORMED AT MIRAVISTA DIAGNOSTICS [1]

Compounded bulk powder

• Not FDA approved
• Subtherapeutic, poor absorption in 98%

Generic and brand name Sporanox comparable
• FDA approved
• Subtherapeutic in 22 to 24%
• Therapeutic 43 to 55%
• Potentially toxic in 18 to 35%

chart-for-findings-recent-clinical-study-miravista-diagnostics

RECOMMENDATIONS

  • Use only FDA approved itraconazole
  • Take with food to maximize absorption and blood levels
  • Measure blood levels 2 weeks (dogs) or 3 weeks (cats) after starting or changing dose to reach steady state blood level
    • Increase dose if level below 2μg/mL
    • Decrease dose if levels above 10μg/mL
  • Include loading dose (5mg/kg BID) for moderately ill patients to reach steady state blood levels sooner and achieve more rapid response

BENEFITS

  • Better overall response
  • Lower risk for relapse
  • Lower toxicity
  • Lower overall cost

VETERINARY ITRACONAZOLE BIOASSAY by MiraVista Diagnostics

TEST CODE: 312
METHODOLOGY: Bioassay
TURNAROUND: Testing is performed on Wednesdays. Results are released the next morning.
LIMITATIONS: Results are not intended to be used asthe sole means for clinical diagnosis or patientmanagement decisions.

  • The bioassay is not accurate if the patient has taken another antifungal agent concurrently or within the prior week.
  • Concentration determined on a single specimen may not reflect future concentrations because of changes in adherence, drug dosage, route of administration, absorption, or receipt of other medication affecting absorption or metabolism of the azole.
  • Follow-up testing may be necessary if there are changes in treatment, including starting or stopping interacting medications, or suspicion of treatment failure.
  • Drug levels should be measured after treatment, of at least 2 weeks in dogs and 3 weeks in cats, to reach a steady state.

INTERPRETIVE INFORMATION:

  • None Detected: Reported when there is no zone of inhibition.
  • <0.3 μg/mL: Reported when the zone of inhibition is smaller than that of the lowest calibrator.
  • Positive: 0.3 – 20.0 μg/ml
  • >20.0 μg/mL: Reported when the zone of inhibition is greater than the highest calibrator.

CLINICAL SIGNIFICANCE: Monitors blood itraconazole concentrations in animals during antifungal drug treatment to determine therapeutic levels.
SPECIMEN REQUIREMENTS: Serum or Plasma ONLY. Any other type of specimen will be rejected.
SPECIMEN MINIMUM: 0.25 ml Serum/ Plasma
COLLECTION INSTRUCTIONS: Refrigerated/Frozen

  • Preferable to collect blood sample at trough time.
  • SERUM: Collect serum specimens in serum separator or red top tube. Allow blood to clot for 30 minutes, then centrifuge. Pipette serum into a plastic screw cap vial.
  • PLASMA: Collect plasma specimens in an EDTA or heparin tube. Centrifuge for 15 minutes and pipette plasma into a screw cap vial.

SPECIMEN STABILITY: 7 Days Room Temperature/Refrigerated/Frozen
TRANSPORT TEMPERATURE: Refrigerated/Frozen
SHIPPING INSTRUCTIONS: Ship refrigerated/frozen specimen on dry ice or frozen cool pack for Next Day Delivery Monday – Friday.

REFERENCE LIST

(1) Renschler, J., et al., Comparison of Compounded, Generic, and Innovator-Formulated Itraconazole in Dogs and Cats. J Am Anim Hosp Assoc, 2018. 54(4): p. 195-200.

CREDENTIALS:
CREDENTIALS: