Prescription for Obesity - It Could Be Your Pills; Researchers Link Some Medications to Weight Gain
May 18, 2004
The pills millions of people take every day for diabetes, clinical depression, high blood pressure and other illnesses are small, weigh almost nothing and carry few calories.
So it may seem hard to swallow, but certain prescription drugs can cause people to gain weight. Fast. Sometimes a pound a week.
Both doctors and patients overlook the possibility that weight gain can originate in the medicine chest, not just fast-food restaurants or couch-potato lifestyles, according to Dr. Lawrence Cheskin, director of the Weight Management Center at Johns Hopkins University in Baltimore.
"While obesity is being more widely recognized, I'm not sure the same can be said for patients' and physicians' recognition of the possible contributing role of prescription medicines," he said in an interview.
Cheskin and his associates first warned about the problem in the 1990s, after noticing that a lot of patients who sought help at their weight management center were getting heavier when they started prescription drugs.
One 42-year-old woman, for instance, gained 42 pounds after taking lithium, a drug for mood swings. A 36-year-old supermarket worker gained 240 pounds while taking prednisone, a steroid.
Weight gain is among the side effects listed in official information sheets for some of the most frequently prescribed drugs in the United States. These include drugs taken by tens of millions of people for diabetes, depression, high blood pressure, gastric reflux and heartburn, and serious mental disorders.
"Weight-gain drugs" is how Dr. George Bray, an obesity expert at Louisiana State University, describes such medications.
Nobody knows exactly how many prescription drugs fall into those categories. Lists published in medical journals vary. One provided by Dr. George Blackburn, an obesity authority at Harvard University, includes more than 50 common drugs.
Internet drug discussion sites such as RxBoard carry accounts from patients who say they got fat after starting anti-cholesterol and other drugs not thought to cause much weight gain.
Non-prescription drugs also might cause weight gain. The antihistamine diphenhydramine, for instance, is on Blackburn's list. It is an ingredient in dozens of popular cold and allergy remedies, sleep aids and drugs to prevent motion sickness. An increasing number of prescription drugs, including some linked to weight gain, are also becoming available for sale without a prescription.
In some cases, it takes years for weight gain to emerge as a troublesome side effect.
When the Prozac-Zoloft-Paxil family of popular anti-depressants hit the market, doctors thought they caused weight loss. They were even prescribed for obese people trying to lose weight. Later, doctors realized that any weight loss is temporary, with the drugs often causing long-term weight gain.
But while studies show that "weight-gain" drugs can cause obesity in individual patients, researchers can't tell how much medicines contribute to the societywide epidemic of obesity. Bray has found that the number of obese people in the United States remained fairly steady - about 20 percent of men and 15 percent of women - until the mid-1970s. Then it took off; by 2000 the rates had risen 100 percent among men and 50 percent among women.
Use of prescription drugs rose during that period, and exploded in the 1990s. In 1993, the number of prescriptions written each year edged over the 2 billion mark for the first time. It reached 3 billion by 1999, and will top 4 billion by the end of 2004, according to the Association of Chain Drug Stores.
Almost every person in the United States now takes at least one prescription drug in a given year. Factor in people who take multiple drugs, and doctors write an average of 12 prescriptions annually for every person in the country.
Since average weight has been rising during the same period, weight-gain drugs have likely played a role in the obesity epidemic, although probably not as much as changes in diet, Bray said.
DRUGS AND WEIGHT GAIN
Here are a few of the common prescription drugs that may cause weight gain:
Anti-depressants - Prozac, Zoloft, Paxil
Heartburn drugs - Nexium, Prevacid
Mental disorder treatments - Clozaril and Zyprexa
Diabetes drugs - Glucotrol, Diabeta, Diabinese
High blood pressure drugs - Minipress, Cardura, Inderal
A physician's list of about 50 "weight-gain" drugs and possible alternatives can be found at: Medications That Cause Weight Gain (Adobe Acrobat PDF file)