SAN DIEGO, CA—Liposomal amphotericin B (L-AMB) may have less renal toxicity than amphotericin B lipid complex (ABLC), making it the “preferred agent” in patients with baseline renal impairment being treated for severe coccidioidomycosis, a presentation at IDWeek 2015 concluded.

Both agents, however, are “highly efficacious” in the treatment of severe coccidioidomycosis—also known as “cocci” and “Valley Fever”—a mammalian fungal disease caused by inhalation of Coccidioides arthroconidia. Kern County has one of the highest burdens of coccidioidomycosis-related hospitalizations in California, and those with severe disease are often treated with ABLC or L-AMB. However, “to date, there have not been any studies that describe the efficacy or safety of these lipid-based therapies in the treatment of severe coccidioidomycosis,” noted David Benjamin Lash, PharmD, MPH, of the Kern Medical Center Department of Clinical Pharmacy in Bakersfield, CA.

Dr. Lash and colleagues retrospectively reviewed charts for all patients with coccidioidomycosis who received L-AMB or ABLC, with treatment initiated at Kern Medical Center and at least one follow-up complement fixation (CF) titer, from January 1, 2000 to December 31, 2014. Of the 121 patients identified, 69 were included in the study, 37 in the ABLC group and 32 in the L-AMB group. Excluded were those who were pregnant (n=16), had lack of follow-up (n=11), death in hospital (n=11), incomplete records (n=10), and treatment-emergent adverse events (n=5), as was 1 patient who was included twice.

The primary outcome was treatment success, which was defined as a 50% or greater decrease in Mycosis Study Group (MSG) score from baseline. Among all patients, median age was 38.1 years; 76.8% were men; and 49.3% were Hispanic. Treatment duration was 18.5 weeks.

Results showed that pulmonary disease was the most common site of infection for all patients (78.2%), followed by bone (56.5%), soft tissue (27.5%), cutaneous (13.0%), and lymph (5.8%), they reported. The most commonly reported symptoms were fever, cough, night sweats, and myalgia/arthralgia.

Both ABLC and L-AMB resulted in a significant decrease in MSG score (P<0.001), Dr. Lash noted. Treatment was successful in 73.0% (n=27) of the patients who received ABLC and 68.8% (n=22) of those who received L-AMB (P=0.700). Further, there were no statistical differences in gender, age, ethnicity, and comorbid conditions or in cocci disease burden—defined as symptoms, CF titers, and MSG score—in patients who received ABLC compared with those who received L-AMB.

Those who received L-AMB were more likely to have previously diagnosed chronic kidney disease (12.5% vs. 0.0%; P=0.042) and have a lower creatinine clearance at treatment initiation (79.6mg/dL vs. 100.4mg/dL; P=0.008); however, only 1 patient (3.0%) treated with L-AMB had acute kidney injury as the documented reason for treatment cessation compared with 10 patients (23.3%) who had received ABLC.

“Prescriber bias may have affected who received which amphotericin formulation and also who was designated as having acute kidney injury,” they noted.

Completion of therapy was documented for 53.5% (n=23) of patients receiving ABLC and 57.6% (n=19) of those receiving L-AMB (P=0.722). “More studies are needed to compare the efficacy of these agents as well as the efficacy of the newer azoles and their different formulations,” Dr. Lash concluded.