News in brief - Sept. 18, 2006

Acne drug associated with abnormal lipids, liver enzymes - Study suggests arthritis, central nervous system link - Asthma linked to increased sleep apnea risk in young women - Warnings added to ADHD drug label - Assay allows for quick flu strain ID

Acne drug associated with abnormal lipids, liver enzymes

Patients taking isotretinoin are more likely to have elevated cholesterol and liver enzymes than previously thought, according to a study in the August Archives of Dermatology.

Researchers at the University of California, San Francisco, analyzed medical records for patients enrolled in a comprehensive managed care plan who were taking this drug. Of those who had normal lab values before taking it, 44% developed elevated triglyceride levels. Thirty-one percent experienced increases in their total cholesterol and, for 11% of patients, the transaminase level went up.

The package insert notes this drug may cause about 25% of patients to have elevated triglycerides and 15% to have increases in liver enzymes.

The authors concluded that the rates of some abnormal lab values were greater than noted in previous studies but also pointed out that the clinical significance of these changes was still unknown. Most levels return to normal after treatment ends.

Study suggests arthritis, central nervous system link

Interrupting signals between joints and the central nervous system has the potential to ameliorate arthritis, according to a paper in the September Public Library of Science Medicine.

Researchers studying rats with induced arthritis found that inflammation of the joints was sensed and affected by p38 MAP kinase, an enzyme that transmits information from the spinal cord to peripheral tissues. Blocking this enzyme was also possible and resulted in a reduction in inflammation and damage to the joints.

Beneficial effects were noted when the drug was targeted to the spinal cord but not when it was delivered systemically.

The authors suggest that this finding may lead to new, more targeted treatments for arthritis.

Asthma linked to increased sleep apnea risk in young women

Women who have asthma are almost twice as likely to snore, exhibiting one of the main signs of obstructive sleep apnea syndrome, according to a study published in the August Annals of Allergy, Asthma and Immunology.

Researchers sent questionnaires to the mothers of participants in the Cincinnati Childhood Allergy and Air Pollution Study, a project looking at children who are at high risk for allergic disease because at least one parent has this problem. Just more than 34% of these women, who had an average age of 30, snored a least once a week with about 12% snoring almost every night. These numbers are significantly higher than the prevalence usually found in studies that look at the general population.

The paper's authors hope that this information will put an end to the notion that obstructive sleep apnea is primarily a problem of men. They also hope the findings will be used to better target the rather expensive tests used to diagnose the condition.

"Physicians need to know the risk factors that predispose a patient to obstructive sleep apnea so we can get those patients in for a conclusive test -- such as a sleep study -- and start treatment sooner," said Maninder Kalra, MD, lead author and assistant professor of pediatrics at the University of Cincinnati College of Medicine.

Warnings added to ADHD drug label

At the request of the Food and Drug Administration, warnings of possible cardiac and psychiatric adverse events have been added to the label of the drug dextroamphetamine, according to a letter issued by GlaxoSmithKline, the drug's manufacturer.

The agency took this action after two advisory committees met earlier this year and recommended adding such warnings to the information accompanying stimulant drugs used to treat attention-deficit/hyperactivity disorder. The agency decided against a black-box warning.

The label for this drug now warns that misuse can lead to sudden death and serious cardiovascular disease. Usual use also can lead to similar adverse events in those who have preexisting cardiac issues. The label advises that physicians asses patients' heart health before prescribing and evaluate promptly if symptoms of heart trouble develop.

The new label also warns that these drugs can exacerbate preexisting psychological problems, increase the risk of seizures and suppress growth in some children.

Assay allows for quick flu strain ID

A novel lab test can genetically type an influenza virus within 12 hours, says a pair of papers in the August Journal of Clinical Microbiology. Researchers hope the test will be used broadly to identify rapidly which flu strains are circulating and to detect early any strains that could become a pandemic version, such as H5N1.

"The ability to quickly and accurately identify strains of influenza would be invaluable to international flu surveillance efforts," said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Disease. "This is an encouraging advance." NIAID funded the study.

Researchers at the University of Colorado, Boulder, developed the FluChip using influenza isolates and lab facilities provided by the Centers for Disease Control and Prevention.

They were able to fully characterize 72% of isolates and partially identify another 13%. The remaining isolates either could not be subtyped or led to false-negative or false-positive test results. These issues were usually not due to the nature of the test but because of difficulties in the nucleic acid amplification required, according to the authors. Scientists intend to continue to refine this test until it is possible to get accurate results in less than one hour.