In clinical studies and postmarketing reports, the side effects seen in 1% or more of the patients were as follows:

Gastrointestinal system: nausea, vomiting, abdominal pain, and diarrhea
Central nervous system: headache
Whole body: fever, phlebitis or thrombophlebitis, complications at the intravenous cannulation site (e.g. induration), unspecified pain, flu-like syndrome, myalgia, chills, and paresthesia
Respiratory: dyspnea
Renal: increased plasma creatinine
Hematological: anemia
Electrolytes: hypokalemia
Liver: increased liver enzymes (asymptomatic)
Hypersensitivity: rash, facial edema, pruritus
Other: tachycardiaAdditionally, infrequent cases of symptomatic liver damage, peripheral edema and swelling, and hypercalcemia have been seen. One case of anaphylaxis (severe allergic reaction) has also been noted. Resistance
Resistance in C. albicans has been described, but is currently still rare. The mechanism is probably a point mutation in the (1→3)-β-D-glucan synthase gene. Drug interactions
Cyclosporin: see under hepatic effects
Tacrolimus: potential pharmacokinetic interactions
Other systemic antimycotic agents: with amphotericin B, itraconazole and mycophenolate, no interactions have been seen
Inducers of drug clearance (e.g. carbamazepine, phenytoin, rifampin, dexamethasone): consider 70 mg intravenous as maintenance dose instead of 50 mg

Duration of treatment
The mean duration of therapy in previous studies was 34 days. Some patients were even healed by a one-day treatment. However, a few patients were treated for as long as 162 days and tolerated the drug well, indicating that longtime use may be indicated and tolerated favourably in complicated cases of aspergillosis. Generally, the duration of treatment is dictated by the severity of the disease, the clinical response, and the improvement of immunocompetence in immunocompromised patients. Dosage
An initial dose of 70 mg by intravenous infusion is given followed by 50 mg intravenous daily.
Its currently approved therapeutic indications by both organisations include the empirical therapy of presumed fungal infections in febrile, neutropenic adult patients and for salvage therapy in patients treatment of invasive aspergillosis in adult patients whose disease is refractory to, or who are intolerant of, other antifungal agents (i.e., conventional or lipid formulations of amphotericin B and/or itraconazole). Additionally, the FDA approval includes indication for the treatment of candidemia and some specific Candida infections (intra-abdominal abscesses, peritonitis, pleural cavity infections, and esophagitis) and the EMEA approval includes indication for the treatment of general invasive candidiasis in adult patients. Metabolism
Slowly metabolized by peptide hydrolysis and N-acetylation in liver. Therefore, in case of liver impairment the dose needs to be reduced. Caspofungin also undergoes spontaneous chemical degradation to an open-ring peptide compound, L-747969. Additional metabolism involves hydrolysis into constitutive amino acids and their derivatives, including dihydroxyhomotyrosine and N-acetyl-dihydroxyhomotyrosine. Clinical efficacy
About 36% of patients refractory to other therapies responded well to caspofungin therapy, while even 70% of patients intolerant to other therapies were classified as responders. Direct comparative studies to other drugs in the treatment of invasive aspergillosis have so far not been undertaken. Contraindications
Known hypersensitivity to caspofungin acetate or any other ingredient contained in the formulation contraindicate its use. Warnings
Hepatic effectsThe concomitant use of caspofungin and cyclosporine in healthy volunteers led to a more frequent increase of liver enzymes (ALT=SGPT and AST=SGOT) than noted with cyclosporine alone. Combination treatment is only indicated if the potential benefit for the patient outweighs the potential risk.