Your liver is the principal organ charged with detoxifying foreign compounds entering your body. Most potentially toxic substances gain access to your body through your gastrointestinal tract, but, with the advent of intravenous medications and drugs of abuse, your liver must also contend with toxins that are directly injected into your circulation. Occasionally, such agents damage your liver’s cells, leading to the release of enzymes into your bloodstream. Chemotherapeutic drugs, such as Gemzar, are commonly associated with elevated liver enzymes.
Lower Toxicity
Gemzar, known generically as gemcitabine, is a chemotherapeutic agent used to treat a variety of carcinomas, including cancers of the breast, pancreas, bladder and lung. A study published in the January 2011 issue of “PLoS One” suggests the drug could also be useful as a treatment for HIV. Gemzar exerts its anticancer effects by interfering with the synthesis of new chromosomes, thereby inhibiting tumor growth. Gemzar is reputedly less toxic than many other forms of chemotherapy, but it can cause liver injury.
Metabolism
Gemzar must be administered intravenously because enzymes in the gastrointestinal tract break it down; it would not be particularly effective if taken orally. Following its administration, an enzyme called cytidine deaminase, or CDA, which is found in tissues throughout your body, metabolizes Gemzar. In fact, a study published the June 2010 issue of the “European Journal of Clinical Pharmacology” indicates that more than 90 percent of a Gemzar dose is inactivated by CDA. However, the duration of exposure to Gemzar, and thus the potential for liver toxicity, is determined by the amount of CDA in all of your organs and tissues, which is in turn, is determined by your specific genetic makeup.
Enzyme Elevation Not Unusual
Clinical trials with Gemzar indicate that approximately 70 percent of patients receiving the drug experience at least transient elevations of their liver enzymes, according to Drugs.com. Liver toxicity supposedly does not increase with longer exposure or total dosage of Gemzar, but some cases of fatal liver damage have been reported even in patients receiving recommended doses. In 2008, physicians at Japan’s Toranomon Hospital reported the case of a 79-year-old man with diabetes and chronic hepatitis C who developed fatal liver failure following institution of Gemzar therapy.
Considerations
Gemzar, like most chemotherapeutic agents, is potentially toxic to your liver, and its use is associated with elevated liver enzymes in the majority of patients who receive it. Usually, liver toxicity caused by Gemzar is mild, temporary and completely reversible upon discontinuation of the drug. However, if you have other conditions affecting your liver, or if you take other medications that could harm your liver, the potential for serious liver injury from taking Gemzar increases. If you are receiving Gemzar therapy, inform your doctor if you have a history of liver disease, and do not take any new medications or supplements without first checking with your physician.
References
- “PLoS One”; Analysis of the Ex Vivo and In Vivo Antiretroviral Activity of Gemcitabine; C.L. Clouser, et al.; January 2011
- “European Journal of Clinical Pharmacology”; Pharmacokinetics of Gemcitabine in Non-Small-Cell Lung Cancer Patients: Impact of the 79A>C Cytidine Deaminase Polymorphism; J.G. Maring, et al.; June 2010
- Drugs.com: Gemzar
- “Gan To Kagaku Ryoho (Cancer Chemotherapy)”; Fatal Liver Failure Associated with Gemcitabine Hydrochloride Therapy; M. Matsuda, et al.; January 2008
