Caspofungin

Structure of caspofungin. Source: NIH.

Caspofungin is in a class of drugs called echinocandins^[1] and is made and marketed by Merck & Co. in the United States.

Uses

Scanning electron micrograph of Candida albicans showing buds and bud scars. Source: NIH.

• presumed fungal infections in patients who have a fever and neutropenia (low neutrophils in the blood).
• infection caused by Candida fungal species involving the following:
  • the bloodstream (candidemia).
  • the lining of the abdomen (peritonitis).
  • the space between the lungs and chest wall (pleural space).
  • the esophagus (esophagitis).
• severe fungal infections caused by Aspergillus species (a condition called Aspergillosis) in people who cannot tolerate other antifungal medications or where other medications have not worked.

How Caspofungin is Taken

Caspofungin is only available for use as a solution given into the vein (intravenously). It is not available in a form that can be taken by mouth. For most indications, the usual dose given is a 70 mg single dose on the first day of treatment, followed by 50 mg given as a daily single dose thereafter.

How It Works

Caspofungin acetate is a complex, semisynthetic molecule with lipid and peptide substructures. It is derived from a fermentation product (pneumocandin B0) of the anamorphic fungus Glarea lozoyensis. It inhibits the synthesis of an essential component of the cell wall of many fungi, the glucose homopolymer β-(1,3)-D-glucan, which is absent in mammals. This interferes with fungal cell wall synthesis, leading to instability and death of the fungal cell. ^{[1] [2] [3]}

Side Effects

Caspofungin and other medicines like it can cause a serious allergic reaction. Signs of a serious allergic reaction include the following:

• sudden problems breathing
• swelling of the lips or tongue
• sudden cough
• hives (bumps on the skin that itch and develop suddenly)
• rash

Other side effects that have been reported in more than 2% of research subjects include the following:

• fever
• chills
• skin reaction at the site where the drug is given
• nausea
• sweating
• nausea and vomiting
• diarrhea
• headache
• lowing of potassium levels in the blood

Risks and Precautions

Caspofungin has been associated with abnormalities in the liver including the following:

• elevation of liver function tests (indicating that the liver is impaired).
• hepatitis (inflammation of the liver).
• worsening liver failure.

Because the use of caspofungin with cyclosporin (an immunosuppressant drug used in organ transplant recipients) may temporarily cause problems in the liver, this combination should only be used when the potential benefit outweighs the potential risk.

When caspofungin is used with certain medications such as rifampin, nevirapine, efavirenz, dexamethasone, or phenytoin, the dose of caspofungin may need to be increased.

It is not known if caspofungin is excreted in maternal milk, and caution should be exercised when caspofungin is given to nursing women.

Alternatives

Other classes of antifungal drugs are available.^[4] Amphotericin B is another antifungal drug effective against Candida. Caspofungin compares favorably to amphotericin B in terms of effectiveness and side effects.

Research

In one study comparing caspofungin with amphotericin B in patients with candidal esophagitis, 74% of those on caspofungin achieved clinical resolution of candida infection versus 63% in the amphotericin B group.^[5]

In a randomized, double-blind study comparing caspofungin with amphotericin B in 1095 patients with fever and low white blood cell count of unknown cause, the overall success rate in those who received caspofungin was 33.9% compared with a success rate of 33.7% in those on amphotericin B. This result shows that caspofungin is as effective as the standard therapy, amphotericin B, in this class of patients.^[6]

Clinical Trials

For a list of clinical research trials that are studying caspofungin, please visit clinical trials.

References

1. ↑ ^{1.0 1.1} Letscher-Bru V, Herbrecht R. Caspofungin: the first representative of a new antifungal class. J Antimicrob Chemother. 2003;51:513-521. Abstract
2. ↑ Keating G, Figgitt D. Caspofungin: a review of its use in oesophageal candidiasis, invasive candidiasis and invasive aspergillosis. Drugs. 2003;63:2235-2263. Abstract
3. ↑ McCormack PL, Perry CM. Caspofungin A: review of its use in the treatment of fungal infections. Drugs. 2005;65:2049-2068. Abstract
4. ↑ Chen SC, Sorrell TC. Antifungal agents. Med J Aust. 2007 Oct 1;187(7):404-9. Abstract | Full Text | PDF
5. ↑ Villanueva A, Arathoon EG, Gotuzzo E, Berman RS, DiNubile MJ, Sable CA. A randomized double-blind study of caspofungin versus amphotericin for the treatment of candidal esophagitis. Clin Infect Dis. 2001 Nov 1;33(9):1529-35. Abstract | Full Text | PDF
6. ↑ Walsh TJ, Teppler H, Donowitz GR, et al. Caspofungin versus liposomal amphotericin B for empirical antifungal therapy in patients with persistent fever and neutropenia. N Engl J Med. 2004 Sep 30;351(14):1391-402. Abstract | Full Text | PDF

External Links

Food and Drug Administration (FDA): Caspofungin Consumer Drug Information Sheet