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Figure  . CAM update: Carnitine supplement tested for fatigue relief in cancer patients, PC-SPES still undergoing studies, and drug interactions with St. John's Wort.

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According to a report in the British Journal of Cancer (2002;86:1854–1857), replacing the body's pool of carnitine might help reduce fatigue in some patients receiving chemotherapy.

“Fatigue is a very common side effect of chemotherapy and radiation therapy,” said Terri Ades, RN, MS, AOCN, Director of Quality of Life and Health Promotion Strategy for the American Cancer Society. “Different treatments are needed for the different causes of fatigue,” Ades said. “Since the exact cause is not always known, more research is needed to help us better understand fatigue and how best to treat it.”

Previous studies have found chemo-therapy regimens that include either ifosfamide or cisplatin sometimes deplete pools of carnitine, a metabolite produced in the liver and kidneys and stored in skeletal muscle, where it is used as an energy source. These two drugs may disrupt the normal production of carnitine and increase the amount released in urine.

“After chemotherapy, many patients have low levels of carnitine in their blood and we think that's one of the reasons they feel so exhausted,” said first author Francesco Graziano, MD, of the Medical Oncology Unit at Urbino Hospital in Urbino, Italy. “It seemed logical that boosting cartinine levels with a dietary supplement might restore that lost energy.”

Graziano and colleagues studied the effect of levocarnitine (LC) as a dietary supplement using four grams per day for one week in 50 patients with either lung, gastric, ovarian, or pancreatic cancer. Patients with low carnitine levels, who felt fatigued during chemotherapy with either ifosfamide or cisplatin, were eligible to participate. Those with other conditions that could cause fatigue, such as anemia, were excluded.

On average, the patients' blood carnitine levels rose 50 percent and returned to within the normal range in all patients. Scores on the Functional Assessment of Cancer Therapy-Fatigue scale improved for 45 patients, remained stable in three, and worsened in two. The most common benefit cited among the 45 patients was increased strength in their legs. Hemoglobin levels did not change significantly during that period of time. Also, the LC supplements had no apparent negative impact on the effectiveness of the chemotherapy.

“Carnitine is widely available as a dietary supplement in pharmacies and health food stores, and is often used by those without health problems to boost athletic performance or lose weight,” said Andrew Vickers, PhD, of the Integrative Medicine Service at Memorial Sloan-Kettering Cancer Center. “Though the balance of evidence is that if you are healthy, carnitine cannot make you more so, there are increasing data from randomized trials suggesting that carnitine can be of benefit to patients with poor physical function due to serious illness such as intermittent claudication, congestive heart failure, or diabetes.”

Ades warned, even though these results may be promising, “Because this is a very early study, there are still many questions to be answered with more research before a recommendation can be made about the use of carnitine as a treatment for fatigue.” The authors agreed that their “…data should be looked at with caution due to potential biases and limitations inherent to the study itself…despite its limitations, the findings of this study are intriguing and open new perspectives for future clinical trials.”