Efficacy of Intravenous Liposomal Amphotericin B (AmBisome) against Coccidioidal Meningitis in Rabbits

ABSTRACT The efficacy of intravenously administered liposomal amphotericin B (AmBisome [AmBi]) for the treatment of experimental coccidioidal meningitis was compared with those of oral fluconazole (FLC) and intravenously administered conventional amphotericin B (AMB). Male New Zealand White rabbits were infected by intracisternal inoculation of arthroconidia of Coccidioides immitis. Starting 5 days postinfection, animals received one of the following: 5% dextrose water diluent; AMB given at 1 mg/kg of body weight; AmBi given at 7.5, 15, or 22.5 mg/kg intravenously three times per week for 3 weeks; or oral FLC given at 80 mg/kg for 19 days. One week after the cessation of therapy, all survivors were euthanatized, the numbers of CFU remaining in the spinal cord and brain were determined, and histological analyses were performed. All AmBi-, FLC-, or AMB-treated animals survived and had prolonged lengths of survival compared with those for the controls (P < 0.0001). Treated groups had significantly lower numbers of white blood cells and significantly lower protein concentrations in the cerebrospinal fluid compared with those for the controls (P < 0.01 to 0.0005) and had fewer clinical signs of infection (e.g., weight loss, elevated temperature, and neurological abnormalities including motor abnormalities). The mean histological scores for AmBi-treated rabbits were lower than those for FLC-treated and control rabbits (P < 0.016 and 0.0005, respectively); the scores for AMB-treated animals were lower than those for the controls (P < 0.0005) but were similar to those for FLC-treated rabbits. All regimens reduced the numbers of CFU in the brain and spinal cord compared with those for the controls (P ≤0.0005). AmBi-treated animals had 3- to 11-fold lower numbers of CFU than FLC-treated rabbits and 6- to 35-fold lower numbers of CFU than AmB-treated rabbits. Three of eight animals given 15 mg of AmBi per kg had no detectable infection in either tissue, whereas other doses of AmBi or FLC cleared either the brain or the spinal cord of infection in fewer rabbits. In addition, clearance of the infection from both tissues was achieved in none of the rabbits, and neither tissue was cleared of infection in AMB-treated animals. Overall, these data indicate that intravenously administered AmBi is superior to oral FLC or intravenous AMB and that FLC is better than AMB against experimental coccidioidal meningitis. These data indicate that AmBi may offer an improvement in the treatment of coccidioidal meningitis. Additional studies are warranted.

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Experimental Models of Short Courses of Liposomal Amphotericin B for Induction Therapy for Cryptococcal Meningitis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00090-17 ◽

2017 ◽

Vol 61 (6) ◽

Cited By ~ 15

Author(s):

Jodi Lestner ◽

Laura McEntee ◽

Adam Johnson ◽

Joanne Livermore ◽

Sarah Whalley ◽

...

Keyword(s):

Amphotericin B ◽

Induction Therapy ◽

Liposomal Amphotericin ◽

Experimental Models ◽

Liposomal Amphotericin B ◽

Perivascular Spaces ◽

Histopathological Changes ◽

Time Curve ◽

Cryptococcal Meningoencephalitis ◽

The Brain

ABSTRACT Cryptococcal meningoencephalitis is a rapidly lethal infection in immunocompromised patients. Induction regimens are usually administered for 2 weeks. The shortest effective period of induction therapy with liposomal amphotericin B (LAMB) is unknown. The pharmacodynamics of LAMB were studied in murine and rabbit models of cryptococcal meningoencephalitis. The concentrations of LAMB in the plasma and brains of mice were measured using high-performance liquid chromatography (HPLC). Histopathological changes were determined. The penetration of LAMB into the brain was determined by immunohistochemistry using an antibody directed to amphotericin B. A dose-dependent decline in fungal burden was observed in the brains of mice, with near-maximal efficacy achieved with LAMB at 10 to 20 mg/kg/day. The terminal elimination half-life in the brain was 133 h. The pharmacodynamics of a single dose of 20 mg/kg was the same as that of 20 mg/kg/day administered for 2 weeks. Changes in quantitative counts were reflected by histopathological changes in the brain. Three doses of LAMB at 5 mg/kg/day in rabbits were required to achieve fungicidal activity in cerebrospinal fluid (cumulative area under the concentration-time curve, 2,500 mg · h/liter). Amphotericin B was visible in the intra- and perivascular spaces, the leptomeninges, and the choroid plexus. The prolonged mean residence time of amphotericin B in the brain suggests that abbreviated induction regimens of LAMB are possible for cryptococcal meningoencephalitis.

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Disseminated Coccidioidomycosis Presenting as Polyarticular Septic Arthritis: A Case Report

Journal of Investigative Medicine High Impact Case Reports ◽

10.1177/2324709620974894 ◽

2020 ◽

Vol 8 ◽

pp. 232470962097489

Author(s):

Faisal Nasrawi ◽

Arash Heidari ◽

Thulfiqar Aljashamy ◽

Nishan Mangat ◽

Jasbir Bhaika ◽

...

Keyword(s):

Amphotericin B ◽

Liposomal Amphotericin ◽

Complement Fixation ◽

Left Knee ◽

Liposomal Amphotericin B ◽

Fungal Culture ◽

Coccidioides Immitis ◽

Rheumatology Clinic ◽

Hispanic Male ◽

Purulent Drainage

Coccidioidomycosis a fungal infection endemic to southwestern United States. It is caused by inhalation of spores of Coccidioides immitis. Sixty percent of infections are asymptomatic; the remaining 40% are primarily pulmonary disease. In <1% of infections, dissemination can occur. Dissemination usually affects those with impaired cellular immunity and pregnant women, and can involve bones, joints, meninges, and skin. We present the case of a 29-year-old Hispanic male who presented to the emergency department (ED) complaining of pain and swelling of right wrist and ankle as well as left knee for 2 months. He was referred to rheumatology clinic but returned to the ED as he developed spontaneous purulent drainage from his wrist. In the ED, an arthrocentesis of 2 of the joints showed total nucleated cells of 520 000/cm2 and 90 000/cm2 with 61% and 93% neutrophils, respectively. Fungal culture eventually grew Coccidioides immitis from his wrist and knee. Coccidioidomycosis complement fixation titer came back >1:512. Bone scan showed uptake of adjacent bones in the affected joints. Superimposed bacterial infection of the wrist complicated the treatment course and delayed the start of liposomal amphotericin B. Eventually patient received 12 weeks of intravenous liposomal amphotericin-B with slow clinical improvement and then switched to oral isavuconazonium for maintenance therapy. This case shows that although disseminated polyarthritis coccidioidomycosis is very rare, clinicians should keep the diagnosis of disseminated synovial coccidioidomycosis in mind in patients with risk factors.

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Comparative Efficacies of Lipid-Complexed Amphotericin B and Liposomal Amphotericin B against Coccidioidal Meningitis in Rabbits

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01538-08 ◽

2009 ◽

Vol 53 (5) ◽

pp. 1858-1862 ◽

Cited By ~ 19

Author(s):

Karl V. Clemons ◽

Javier Capilla ◽

Raymond A. Sobel ◽

Marife Martinez ◽

Ann-Jay Tong ◽

...

Keyword(s):

Amphotericin B ◽

Liposomal Amphotericin ◽

Progressive Disease ◽

Clinical Signs ◽

Liposomal Amphotericin B ◽

Control Group ◽

Coccidioides Posadasii ◽

Clinical Assessments ◽

New Zealand White Rabbits ◽

Effective Doses

ABSTRACT In separate previous studies, we have shown that lipid-complexed amphotericin B (Abelcet [ABLC]) and liposomal amphotericin B (AmBisome [AmBi]) are efficacious against coccidioidal meningitis in rabbits. Here, we compared ABLC and AmBi directly in a coccidioidal meningitis model. Male New Zealand White rabbits were infected with 5 × 104 Coccidioides posadasii arthroconidia by direct cisternal puncture. Therapy with intravenous ABLC or AmBi at 7.5 or 15 mg/kg of body weight or sterile 5% dextrose water (D5W) began 5 days later. Clinical assessments were done daily; cerebrospinal fluid and blood samples were obtained on day 15 and upon euthanasia. Survivors to day 25 were euthanatized, the numbers of CFU in their tissues were determined, and histology analyses of the brains and spinal cords were done. Controls showed progressive disease, whereas animals treated with either dose of either drug showed few clinical signs of infection. All ABLC- or AmBi-treated rabbits survived, whereas eight of nine D5W-treated rabbits were euthanatized before day 25 (P < 0.0001). Numbers of CFU in the brains and spinal cords of ABLC- or AmBi-treated animals were 100- to 10,000-fold lower than those in the corresponding tissues of D5W-treated animals (P < 0.0006 to 0.0001). However, only two or fewer given a regimen of ABLC or AmBi were cured of infection in both tissues. Fewer ABLC-treated rabbits (four of eight treated with 7.5 mg/kg and five of eight treated with 15 mg/kg) than controls (nine of nine) had meningitis at any level of severity (P, 0.015 or 0.043 for animals treated with ABLC at 7.5 or 15 mg/kg, respectively). Although groups of rabbits treated with AmBi regimens did not have significantly fewer animals with meningitis than the control group (P > 0.05), ABLC and AmBi were not significantly different. In this model, intravenous ABLC and AmBi were similarly highly effective, with few clinical signs of infection, 100% survival, and significantly reduced fungal burdens among treated animals. There appeared to be little benefit in using the 15-mg/kg dosage of either formulation. There was no significant advantage of one drug over the other for this indication. Further studies are required to determine the lowest effective doses of these formulations.

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