Caspofungin

Summary

Caspofungin is an intravenous echinocandin antifungal that is approved for the treatment of candidaemia and invasive candidiasis. It works by disrupting fungal cell‑wall synthesis and is administered as a daily infusion after a loading dose. Clinical trials have shown it to be non‑inferior to the investigational drug rezafungin, and it is considered a standard option for systemic Candida infections in adults.

Mechanism of Action

Caspofungin belongs to the echinocandin class, which interferes with fungal cell‑wall synthesis. By targeting the enzyme responsible for producing β‑1,3‑D‑glucan, a key structural polysaccharide, caspofungin reduces the integrity of the fungal cell wall, leading to cell lysis and death of susceptible Candida species.

What the Research Shows

A phase‑3, double‑blind trial (ReSTORE) compared intravenous caspofungin (70 mg loading, then 50 mg daily) with once‑weekly rezafungin in 199 adults with candidaemia or invasive candidiasis. Global cure at day 14 occurred in 61% of caspofungin‑treated patients, and 30‑day mortality was 21%, meeting non‑inferiority criteria. Safety data showed treatment‑emergent adverse events in 85% of patients, most commonly pyrexia, hypokalaemia, pneumonia, septic shock and anaemia, with serious events in 53%. A dosing review for continuous renal replacement therapy (CRRT) lists caspofungin among agents needing adjusted regimens, reflecting limited pharmacokinetic data in this setting. Limited intrathecal experience suggests possible use for central nervous system fungal infections, but evidence is sparse. Resistance reviews identify FKS1/2 mutations as mechanisms reducing caspofungin activity against Candida.

Reported Benefits

Clinical evidence demonstrates that caspofungin effectively treats candidaemia and invasive candidiasis, achieving cure rates comparable to a novel echinocandin. Its intravenous formulation allows rapid systemic exposure, and the safety profile in the ReSTORE trial was acceptable, with most adverse events being mild to moderate. The drug’s mechanism targeting the fungal cell wall provides activity against many azole‑resistant strains, and it remains a cornerstone therapy in immunocompromised patients.

Limitations of the Evidence

Evidence for caspofungin in renal replacement therapy is limited to expert review rather than prospective trials, leaving optimal dosing uncertain. Intrathecal administration has only anecdotal support, and no large studies confirm efficacy for central nervous system infections. Resistance can emerge via FKS mutations, potentially compromising treatment. The primary efficacy data compare caspofungin to rezafungin, not to placebo or other standard agents, restricting broader comparative conclusions.

Safety Considerations

In the ReSTORE trial, 85% of caspofungin recipients experienced at least one adverse event; the most frequent were fever, low potassium, pneumonia, septic shock and anemia. Serious adverse events occurred in 53% of patients, similar to the rezafungin group. No specific organ toxicity, such as nephrotoxicity, was highlighted, aligning with the generally favorable safety profile of echinocandins reported in reviews. Monitoring for hematologic and electrolyte disturbances is advised.

How It Is Administered

Caspofungin is administered intravenously, typically as a 70 mg loading dose on day 1 followed by 50 mg daily infusions for up to four weeks. The drug is supplied as caspofungin acetate for infusion. While systemic IV use is standard, limited reports describe intrathecal administration for refractory CNS infections, but this route remains investigational.

Routes of Administration

Goals & Uses

• Treatment of invasive aspergillosisAntifungalHigh
• Antifungal prophylaxis in high-risk patientsProphylaxisModerate
• Treatment of invasive candidiasisAntifungalHigh
• Treatment of esophageal candidiasisAntifungal TherapyHigh
• Prophylaxis in neutropenic patientsPreventionModerate
• Empirical antifungal therapy in febrile neutropeniaAntifungal Prophylaxis/empirical TherapyHigh

Contraindications

• Concomitant use with cyclosporine (relative)Drug InteractionModerate
• Severe hepatic impairment (Child‑Pugh C)Liver DiseaseModerate
• Hypersensitivity to caspofungin or any echinocandinAllergyHigh
• Known hypersensitivity to caspofungin or any componentAllergyHigh

Adverse Effects

• Elevated liver enzymes (AST/ALT)HepatotoxicityCommon
• HypokalemiaElectrolyteCommon
• AnaphylaxisImmunologicRareSevere life-threatening allergic reaction
• Nausea/vomitingGastrointestinalUncommon
• Infusion‑related reactions (fever, chills, rigors)SystemicCommon
• Rash or pruritusDermatologicUncommon
• Infusion-related reactions (flushing, rash, pruritus)Infusion ReactionUncommon
• FeverSystemicCommonElevated body temperature
• Elevated liver transaminases (ALT/AST)HepaticCommon
• DiarrheaGastrointestinalUncommonLoose or frequent stools

Drug Interactions

• RifampinModerate
• CyclosporineModerate
• Efavirenz/Nevirapine/Carbamazepine/Phenytoin/DexamethasoneModerate
• TacrolimusModerate

Population Constraints

• Pregnancy (Category C)ReproductiveRelative
• PregnancyReproductive SafetyRelative
• Pediatric patients (<18 years)AgeRelative
• Pediatric patients under 3 monthsAgeRelative
• Severe hepatic impairment (Child-Pugh >9)HepaticRelative
• BreastfeedingReproductiveRelative

Regulatory Status

• European UnionApprovedApproved: Invasive candidiasis, Esophageal candidiasis, Invasive aspergillosisSame as US
• United StatesApprovedApproved: Invasive candidiasis, Esophageal candidiasis, Invasive aspergillosisIV formulation only
• United KingdomApprovedApproved: Invasive candidiasis, Esophageal candidiasis, Invasive aspergillosisMarketed as Cancidas

FDA approved in 2001 (Cancidas); also approved in the EU and UK. Available only as an intravenous formulation.

Evidence & Sources

• Rezafungin versus caspofungin for treatment of candidaemia and invasive candidiasis (ReSTORE): a multicentre, double-blind, double-dummy, randomised phase 3 trial
  Journal ArticleModerateThompson GR 3rd, et al.2023-01-01T00:00:00.000000Z
• Recommendation of Antimicrobial Dosing Optimization During Continuous Renal Replacement Therapy
  Journal ArticleModerateLi L, et al.2020-01-01T00:00:00.000000Z
• Intrathecal Antibacterial and Antifungal Therapies
  Journal ArticleModerateNau R, Blei C, Eiffert H2020-01-01T00:00:00.000000Z
• Molecular Mechanisms Associated with Antifungal Resistance in Pathogenic Candida Species
  Journal ArticleModerateCzajka KM, et al.2023-01-01T00:00:00.000000Z
• New Perspectives on Antimicrobial Agents: Isavuconazole
  Journal ArticleModerateLewis JS 2nd, et al.2022-01-01T00:00:00.000000Z
• Antifungal agents and the kidney: pharmacokinetics, clinical nephrotoxicity, and interactions
  Journal ArticleModerateTragiannidis A, et al.2021-01-01T00:00:00.000000Z

Frequently Asked Questions