Is your medication making you hungry?
Johns Hopkins University brain scientists found out why some powerful drugs used for treating mental illnesses cause severe weight gain and life-threatening complications such as diabetes and heart disease.
“This will enable the drug industry to design drugs that will not cause weight gain,” said Dr. Solomon Snyder, professor of neuroscience at the Johns Hopkins School of Medicine. “I know of patients who have had an immense weight gain ? one woman was 148 pounds and she gained 100 pounds. She won?t take the drugs, and that?s unfortunate because her psychotic condition was so severe.”
The Hopkins study was published online Monday at the Proceedings of the National Academy of Sciences Web site.
Federal researchers identified cutting side effects as crucial to getting patients to stick with their drug regimen.
Patients with schizophrenia and other severe psychotic disorders are “particularly prone to poor compliance and under a high risk of negative drug interaction,” according to research published by the National Institutes of Health.
Previous research identified increased activity by one particular enzyme, AMPK, in brain cells as a control lever for appetite in mice and presumably humans.
The Johns Hopkins team injected mice with clozapine, part of a common regimen for schizophrenia and bipolar disorder in people who do poorly on conventional drugs.
Clozapine caused a 400 percent spike in AMPK activity compared with before they were medicated, according to the research.
When they gave the mice leptin, a hormone that suppresses appetite, AMPK levels dropped.
Ultimately, researchers found that clozapine affects the same receptors in the brain affected by allergy-producing histamines, and that mice genetically engineered without a histamine receptor had no appetite gain from the prescription.
“Histamine also has a long history as a suspect in weight control, but no one ever could put a finger on the exact link,” Snyder said. “The connection we?ve made between its receptor and appetite control is incredibly intriguing and opens new avenues for research on weight control, possibly including drugs that suppress appetite safely.”
