Dosage reduction in patients with moderately impaired liver function is recommended. No clinical data exist regarding the use of caspofungin in patients with severely impaired liver function. Sensitivity reactionsReactions due to histamine release (rash, facial swelling, pruritus, sensation of warmth and one case of anaphylaxis) have been seen. Health-care providers should carefully watch for these reactions. Drug resistanceIn a few patients with infections caused by Candida albicans, mutants with reduced sensitivity to caspofungin have been noticed. Currently there are no data regarding development of resistance in other fungi than C. albicans. Pregnancy and lactation
Caspofungin has been shown in animal studies to have embroyotoxic properties, and therefore has been assigned to class C. It should only be given to pregnant women if the benefit to the mother clearly outweighs the potential risk to her fetus. The drug is found in the milk of lactating rats, but it is not known whether this is seen in humans. Thus, lactating women should be treated cautiously. Geriatric patients
Ordinarily, no dose adjustments are necessary, however, greater sensitivity of some older individuals cannot be ruled out. Pediatric patients
Caspofungin is FDA approved for pediatric patients 3 months and older. Dosing is based on body surface area (BSA) as calculated by the Mosteller formula. Side effects
Compared to amphotericin B, caspofungin seems to have a relatively low incidence of side effects.
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.