Caspofungin (Cancidas)

How Medicare covers it

Part B (clinician-given intravenous infusion — HCPCS J0637 in the CMS Part B spending file, see the Part B basis in this package). Part D aggregation carried exactly. Part A during a covered inpatient stay.

What it treats

Serious fungal infections in adults and children 3 months of age and older: empirical therapy for presumed fungal infections in febrile, neutropenic patients; candidemia and other Candida infections (intra-abdominal abscesses, peritonitis, and pleural space infections); esophageal candidiasis; and invasive aspergillosis in patients who are refractory to or intolerant of other therapies. Brand name Cancidas.

What it is for, in depth

Cancidas (caspofungin) is a hospital antifungal given by IV infusion to adults and children 3 months and older with serious fungal infections. It is used when a fungal infection is suspected (but not yet proven) in patients who have fever and a low white blood cell count (febrile neutropenia), to treat Candida in the blood and in deep sites such as the abdomen and the lining around the lungs, and to treat Candida infection of the esophagus. For invasive aspergillosis it is a later-line option, used only in patients whose infection did not respond to other therapies or who could not tolerate them; the label states it has not been studied as initial therapy for invasive aspergillosis, and it has not been studied for Candida infections of the heart valves, bone, or meninges. It comes as a powder in single-dose 50 mg and 70 mg vials that is mixed with liquid and infused slowly over about 1 hour once a day.

How it works

Caspofungin is an echinocandin antifungal. It blocks the making of beta (1,3)-D-glucan, an essential building block of the cell wall of susceptible Aspergillus and Candida fungi. Human (mammalian) cells do not contain beta (1,3)-D-glucan, so the drug targets the fungus's cell wall.

How it is taken

Given by a healthcare professional as a slow intravenous (IV) infusion over approximately 1 hour, once a day; it must not be given as an IV bolus (fast push), mixed or co-infused with other medications, or diluted with dextrose-containing diluents. Adults generally receive a single 70 mg loading dose on day 1 followed by 50 mg once daily; for esophageal candidiasis the dose is 50 mg once daily with no loading dose. Children's doses are based on body surface area.

Common side effects

In adults, the most common side effects (10% or more) were diarrhea, pyrexia (fever), increased ALT and AST (liver enzymes), increased blood alkaline phosphatase, and decreased blood potassium. In children, the most common (10% or more) were fever, diarrhea, rash, increased ALT/AST, decreased blood potassium, hypotension (low blood pressure), and chills.

Serious warnings

Hypersensitivity reactions have been reported, including anaphylaxis and possible histamine-mediated reactions such as rash, facial swelling, angioedema, itching, a sensation of warmth, and bronchospasm, and cases of Stevens-Johnson syndrome and toxic epidermal necrolysis (severe skin reactions), some fatal, have been reported; the drug is stopped at the first sign of a hypersensitivity reaction. Caspofungin can cause abnormal liver enzymes, and isolated cases of clinically significant liver dysfunction, hepatitis, and hepatic failure have been reported, so patients who develop abnormal liver tests should be monitored for worsening liver function. Liver enzymes also rose in patients receiving caspofungin together with cyclosporine, so that combination is limited to patients for whom the potential benefit outweighs the potential risk.

Who should be careful

Caspofungin is contraindicated in patients with known hypersensitivity (for example, anaphylaxis) to any component of the product. Adults with moderate liver (hepatic) impairment need a reduced daily dose (35 mg once daily, with a 70 mg loading dose on day 1 where appropriate), and liver function tests should be monitored during therapy in all patients. Patients receiving cyclosporine at the same time should only continue the combination if the potential benefit outweighs the potential risk.

Major interactions

Cyclosporine increases caspofungin exposure (AUC) and co-administration caused transient increases in liver ALT and AST, so liver enzymes are monitored and the combination is used only when the benefit outweighs the risk. Patients also receiving tacrolimus need standard monitoring of tacrolimus blood levels and dose adjustments. Rifampin, a potent inducer of hepatic CYP enzymes, is expected to lower caspofungin levels, so adults on rifampin should receive 70 mg daily; an increase to 70 mg daily should also be considered in adults taking other hepatic enzyme inducers — efavirenz, nevirapine, phenytoin, dexamethasone, or carbamazepine.

Cost and saving notes

This drug is given by IV infusion in a hospital or clinic, so it may be billed under a different part of Medicare than a drug you pick up at a pharmacy; ask the facility and your plan which part covers it and what your share will be before treatment. If a Part D plan covers a related drug cost and it is high, you can ask for a tier exception, and Extra Help (the Part D Low-Income Subsidy) can lower drug costs for people with limited income. In 2027, your total yearly out-of-pocket spending on Part D drugs is capped at $2,400, and you can ask your plan to spread those costs out in monthly payments through the Medicare Prescription Payment Plan.

Why it is in its tier

Caspofungin (Cancidas) sits on Tier 4 in 85.12% of the plans that list it (3639 of 4275 listing plans). Tier 4 is the non-preferred tier — higher copays or coinsurance. The data-visible drivers: It is a generic product, and the CMS dashboard puts its average Part D spending at about $1,099 per beneficiary for 2024 — a mid-cost drug, which matches where plans place it. It is listed by 77.8% of Part D plans. The tier shown is the most common one; individual plans vary.

Sources

• CANCIDAS (CASPOFUNGIN ACETATE) INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION [MERCK SHARP & DOHME LLC] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Caspofungin Injection

What official patient guides say

Caspofungin is not a pill you take at home on your own schedule. It is given as a slow drip into a vein, over about 1 hour, once a day, in a hospital or clinic. In some cases a person may give it at home, but only after a healthcare provider has shown exactly how to do it, and you should ask questions until the directions are clear. There is no food rule to plan around — you can keep your normal diet unless your doctor says otherwise. How many days of treatment you get depends on your general health, the type of infection, and how well you respond, so keeping every appointment and lab visit matters in daily life. You should begin to feel better during the first few days. Tell your doctor if your symptoms do not improve, get worse, or are still there after you finish, and tell the care team how you are feeling during treatment, since your dose may be changed based on your response.

Source: MedlinePlus — Caspofungin Injection

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-07

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 4,275 list Caspofungin (Cancidas) — 77.8% of plans. Most of those plans put it on Tier 4: 3,639 plans, 85.1% of the plans that list it. Other plans place it on Tier 3 (305 plans), Tier 2 (231 plans) or Tier 1 (100 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 4; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 4; Aetna Medicare Value Plus (PPO) puts it on Tier 4. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.