1-[(4R,5S)-5-[(2-aminoethyl)amino]- N2-(10,12-dimethyl-1-oxotetradecyl)- 4-hydroxy-L-ornithine]-5-[(3R)- 3-hydroxy-L-ornithine] pneumocandin B0

Distribution
About 97% protein bound (albumin).

Metabolism
Slowly metabolized by hydrolysis and N-acetylation and undergoes spontaneous chemical degradation.

Elimination
The t ½ is 9 to 11 h (beta phase) and 40 to 50 h (gamma phase). 35% is excreted in feces and 41% in urine (about 1.4% as unchanged drug). Renal Cl is about 0.15 mL/min. Total Cl is 12 mL/min. Not dialyzable.

Special Populations
Renal Function Impairment
AUC is increased 30% to 49% in those with Ccr up to 49 mL/min.

Hepatic Function Impairment
Mild (Child-Pugh score 5 to 6)
AUC is increased about 55%.

Moderate (Child-Pugh score 7 to 9)
AUC is increased 76%.

Elderly
AUC is increased about 28%. No dosage adjustment is needed.

Cyclosporine
Avoid concurrent use if possible because caspofungin levels may be elevated, increasing the risk of side effects.

Inducers or mixed inducers/inhibitors of drug clearance (eg, carbamazepine, dexamethasone, efavirenz, nelfinavir, nevirapine, phenytoin, rifampin)
Caspofungin blood levels may be decreased, reducing the efficacy. Coadministration may require an increase in dose to 70 mg of caspofungin daily.

Tacrolimus
Tacrolimus blood levels may be decreased, reducing the efficacy.

Incompatibility
Do not mix or co-infuse with other medications. Do not use diluents containing dextrose. Caspofungin is not stable in diluents containing dextrose.