As a result of the current Federal government funding situation, the information on this website may not be up to date or acted upon.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit

Updates regarding government operating status and resumption of normal operations can be found at

NCI Drug Dictionary

  • Resize font
  • Print
  • Email
  • Facebook
  • Twitter
  • Google+
  • Pinterest

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

Originally, the name laetrile was the contraction of laevo-mandelonitrile glucoside, a cyanogenic glycoside found naturally in some plants. Over the years the meaning of laetrile has changed. There are now preparations called Laetrile where amygdalin is the major constituent. Laetrile and amygdalin are often used interchangeably, but are different agents. Cyanide and benzaldehyde are metabolites of both laetrile and amygdalin. Both metabolites may possess antineoplastic properties. Laetrile has been used as an anticancer treatment in humans worldwide, but scientific evidence does not support its effectiveness. It is not approved for use in the United States. Check for active clinical trials using this agent. (NCI Thesaurus)