Withdrawn MS drug returns to market
(26 May 2007: VIDYYA MEDICAL NEWS SERVICE) -- Just months after receiving FDA approval, natalizumab, a medication for the treatment of multiple sclerosis (MS) and other inflammatory disorders, was voluntarily withdrawn by its manufacturers after three patients developed a brain infection known as Progressive Multifocal Leukoencephalopathy (PML). Natalizumab has recently been re-approved by the FDA, and a comprehensive article published in the latest issue of CNS Drug Reviews provides a timely overview of the drug, its pharmacological properties, clinical efficacy, safety and toxicology.
MS is a disorder that affects the central nervous system, with leukocytes (inflammatory cells) attacking the bodys neurons and causing serious damage. A highly effective immunosuppressive treatment, natalizumab is an antibody that prevents leukocytes from crossing blood vessel walls into tissues such as the brain and spinal cord.
The drug may also benefit secondary lymphoid organs, such as lymph nodes and the spleen, and inhibit reactivation in the central nervous system. It has been shown to significantly reduce leukocyte cell numbers in spinal fluid, with benefits continuing for six months after treatment.
"The release of natalizumab ushers in a new era in the treatment of MS," says Dr. Olaf Stüve , author of the study, noting, however, that while the short-term risk-benefit ratio appears positive, the long-term risks remain unknown. "As therapy with natalizumab resumes worldwide, the neurologic community will garner more information about the long-term risks and benefits of this powerful therapeutic medication," but for now natalizumab use is being strictly monitored.
Both the FDA and TOUCH, a special distribution program designed to prevent patients not qualified for the treatment from receiving the drug, are working to make sure that any potential infectious complications are identified as early as possible.
Coffee is one of the most widely consumed beverages in the world; more than 50 percent of Americans drink it at the average rate of 2 cups per day. Because of this widespread consumption, its potential effects have important implications for public and individual health. Led by Hyon K. Choi, of the University of British Columbia in Vancouver, Canada, the current study was based on the U.S. Third National Health and Nutrition Examination Survey, conducted between 1988 and 1994. It included over 14,000 men and women at least 20 years old who consented to a medical exam in which blood and urine specimens were obtained. Coffee and tea consumption were determined based on responses to a food questionnaire that assessed intake over the previous month. Researchers estimated the amount of caffeine per cup of coffee or tea using data from the U.S. Department of Agriculture.
The results showed that levels of uric acid in the blood significantly decreased with increasing coffee intake, but not with tea intake. In addition, there was no association between total caffeine intake from beverages and uric acid levels. These results were similar to those found in the only previous study on the topic, which was conducted in Japan. Interestingly, there was an association between decaffeinated coffee consumption and uric acid levels. "These findings suggest that components of coffee other than caffeine contribute to the observed inverse association between coffee intake and uric acid levels," the researchers state.
A recent study found that coffee was associated lower C peptide levels (a marker of insulin levels). The researchers in the current study suggest that because there is a strong relationship between insulin resistance and elevated uric acid levels, the decreased insulin levels associated with coffee consumption may lead to lower uric acid levels. Coffee is also a major source of chlorogenic acid, a strong antioxidant, which may improve insulin sensitivity. Chlorogenic acid also helps inhibit glucose absorption in the intestine; in another study decaffeinated coffee seemed to delay intestinal absorption of glucose and increase concentrations of glucagon-like peptide 1, which is well known for its beneficial effects on insulin secretion and action. The researchers note further that their results could be due to an effect of non-caffeine components found in coffee, which would also explain why coffee affected uric acid levels but tea did not.
Coffee, Tea, and Caffeine Consumption and Serum Uric Acid Level: The Third National Health and Nutrition Examination Survey," Hyon K. Choi, Gary Curhan, Arthritis Care & Research, June 2007; 57:5
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