CPT® Code 80189

Itraconazole is classified as a triazole antifungal medication, primarily utilized in adults for the treatment of various fungal infections. These infections may affect the lungs, where they can potentially spread, as well as cause yeast infections in the mouth, throat, or esophagus. Additionally, itraconazole is effective against fungal infections of the toenails and fingernails. The therapeutic levels of itraconazole are crucial for assessing the systemic absorption of the medication when taken orally, as well as for monitoring potential toxicity. Toxicity from itraconazole can lead to severe complications, including seizures, respiratory difficulties, and heart attacks. Symptoms indicative of toxicity may include blurred or double vision, tinnitus (ringing in the ears), and urinary incontinence. Therapeutic serum levels are typically measured to ensure efficacy and safety, with ranges from above 0.5 mcg/mL for localized infections to 1.0 mcg/mL for systemic infections. These levels are determined using advanced laboratory techniques such as high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection, liquid chromatography-mass spectrometry (LC-MS), or tandem mass spectrometry (LC/MS-MS). In cases where the active metabolite, hydroxyitraconazole, is also assessed, target values for both itraconazole and its metabolite are considered to be around 1.5 mcg/mL combined. The analytical process involves preparing a serum sample mixture or analyte in a solvent, which is then pumped through a chromatographic column under high pressure, propelled by a stream of helium or nitrogen gas. The liquid is nebulized into a fine spray, ionized, and subsequently transferred to the mass spectrometry unit. Within this unit, the itraconazole compound is separated, and the mass spectrometer measures the mass-to-charge ratio of the ions by exposing them to a magnetic or electric field, allowing for sorting based on mass. The quantity of sorted ions is then quantified, and when two mass spectrometry detectors are employed, the selected molecules undergo additional fragmentation analysis. The resulting mass-to-charge data is graphically represented by a computer, which ultimately determines the concentration of itraconazole in the sample.