Organized Chaos - Volumes 1 & 2
Medication Induced Weight Gain: What Can You Do?
by Michael A. Jenike, MD
and Julie A. Jenike, MS, CCC-SLP
Probably the most effective treatment for OCD is Cognitive Behavior Therapy (CBT). Many of you will require medication at least during the initial stages of treatment. Weight gain is one of the most difficult to manage side effects of anti-obsessional medication. There is much you can do. This article summarizes the knowledge about drug-induced weight gain and things that you and your doctor can do to prevent or minimize it. Many doctors are not sensitive to this issue. So you should go to the doctor armed with this information.
How common is weight gain with the various anti-obsessional drugs?
The SSRI medications used to treat OCD are more likely to cause weight gain than other classes of antidepressants. Some SSRIs are more likely to cause weight gain than others. One research group assessed weight changes in patients randomly assigned to long-term treatment with Fluoxetine (Prozac), Sertraline (Zoloft), or Paroxetine (Paxil). They found that the number of patients with 7% weight gain from baseline was significantly greater for Paxil-treated compared with either Prozac-treated or Zoloft-treated patients. Others found similar findings with Paxil more likely to cause weight gain (up to 25% of subjects) than either Prozac (6.8%) or Citalopram (Celexa) (3.9%). Other studies have shown minimal or no weight gains with Celexa. Some patients do not improve much with SSRI medication alone. Doctors sometimes add a second drug in an effort to augment the response. Drugs that are sometimes added are the so-called atypical neuroleptics such as olanzapine (Zyprexa), risperidone (Risperdal), quietiapine (Seroquel) and ziprasidone (Geodon). These drugs can cause weight gain.
Researchers looked specifically at adolescent patients who were treated with Zyprexa, Risperdal, and Haldol (an older neuroleptic). They found that the Zyprexa and Risperdal groups experienced significant weight gain between baseline and after treatment. Whereas the average weight of the Haldol group did not change. Average weight gain was significantly higher for the Zyprexa group than for the Risperdal group. Extreme weight gain (defined as 7% gain) was recorded in 90% of Zyprexa-treated patients compared to 43% of those on Risperdal and 12% (1 patient) on Haldol. Other data suggest that Geodon does not cause weight gain in most individuals. The authors noted that adolescents are more likely to gain weight on medications than adults.
Why do people gain weight on medications?
On medications, one feels sedated and require more sleep. This results in less activity with fewer calories expended throughout the day. There is some evidence that OCD patients choose to snack on carbohydrates, and this predisposes OCD patients to gain weight. The SSRIs are associated with even more carbohydrate craving. Some patients treated with SSRIs have a significant increase in carbohydrate craving together with weight gain shortly after the beginning of treatment.
Since patients gaining weight often say that they are not eating more, it is tempting to speculate that there may be a drug-induced lowering of the metabolism. We could only find one paper demonstrating such a change in metabolism. The authors note that weight fluctuations reflect a balance between caloric intake and caloric expenditure. Thus, weight gain is due to positive energy balance, that may be explained by an increase in total calories consumed and/or a reduction in calories used by the body.
Resting metabolic rate (RMR), reflects the number of calories utilized by an individual in a resting state. It represents at least 70% of the total daily calories burned by an individual. If a reduction in metabolic rate occurs, an individual would gain weight without increasing caloric intake. To determine whether or not alterations in resting metabolic rate might occur in drug-treated depressed patients, they carefully studied three female inpatients hospitalized for depression. Three separate measurements were taken during the drug-free period and again during the second and fourth weeks of antidepressant medication treatment. All three subjects treated with antidepressants showed a decrease in RMR, ranging between 17% and 24%. The authors noted that these changes reflect a reduction in daily caloric requirements of about 300-400 kcal. Thus an individual might to gain a pound every 9-12 days independent of any change in caloric intake. These results support the idea that weight increases occurr during medication treatment are due, at least in part, to changes in metabolic rate. (Kcal measures energy needs) Abbreviation for Kilo Calorie = 1000 calories.
The SSRI medications affect a brain chemical called "serotonin." The effects of serotonin on appetite and food intake can be mediated by activation of specific serotonergic receptors (5-HT2C receptors in the hypothalamus). Receptors are specific sites where drugs act in the brain. Mutant mice that lack these receptors become obese as a result of increased food intake. Drugs that block these receptors cause weight gain in both humans and animals. The administration of drugs that stimulate these receptors result in decreased food intake, decreased subjective hunger, and weight loss.
Celexa, Prozac, and Prozac's metabolite, norfluoxetine, may influence 5-HT2C receptor regulation by binding directly to those receptors. Zoloft was not found to have significant binding to this receptor. Chronic SSRI treatment also has been reported to attenuate the function of 5-HT2C receptors. There may be a number of factors that are contributing to drug-induced weight gain. Other factors include less physical activity, changes in metabolism, and direct effects on serotonergic receptors. Since each of these factors vary from person to person, there can be a wide variability of response. Some patients can gain 100 pounds while others gain nothing.
How can a person prevent or minimize weight gain with diet and exercise?
There are ways to offset weight gain by following some simple, but tried and true methods.
First, keep in mind that you need fewer calories after you start medication if your metabolism is slowed. If you do not lower food intake, you may gain weight. Adopting a healthy diet, with a focus on lean proteins, fresh fruits and vegetables, whole grains, and heart healthy monounsaturated fats like olive and canola oils, is one way to start. Be careful not to eat huge amounts of food at a sitting. Most restaurants give you 3-4 times a suggested serving size. Learn to order sensibly when eating out. Ask for dressings and sauces on the side avoid fried and fatty foods, and order grilled, baked or poached entrees such as chicken, pork tenderloin, and fish.
Exercise is an important factor in preventing weight gain. Cardiorespiratory exercise (i.e. aerobics, walking, biking, jogging) and resistance training (i.e. lifting weights, using resistance bands and tubes) are both equally important. Cardio exercise increases the heart rate and helps to promote improved cardiac fitness. In addition to burning calories and raising metabolism, resistance training helps to build lean muscle. This in turn can cause increased metabolism and decrease in the body's ratio of fat to lean muscle mass.
Combining proper nutrition with cardiorespiratory exercise and resistance training helps prevent weight gain and other health-related ailments. It also increase energy levels which can offset some of the sedative effects of medications. The effects of exercise generate improvements in self-esteem and positive well-being.
What drug options are available to manage weight gain?
If all else fails, we sometimes try adding a second drug for a few weeks to try and assist with weight loss. Cytomel is a thyroid hormone preparation that can be used to speed metabolic rate. It is sometimes used for a few weeks to help weight loss. Sometimes a few weeks of a stimulant drug like Ritalin (Methylphenidate) will help curb appetite. One drug that often helps a lot with weight loss associated with anti-obsessional medication and is safe in low doses (i.e., 50mg) is Topamax (topiramide). There is a recent report on the ulcer drug, Nizatidine, reducing the weight gain associated with Zyprexa by as much as 50% without affecting the effectiveness of the Zyprexa. Chromium Piccolinate is recommended by some people (this can be obtained in health food stores), but we have limited and unimpressive experience to date.
Summary: What can you do to manage weight gain?
- Avoid drugs that have a high likelihood of causing weight gain. The worst offender of the SSRIs medications is Paxil. Another of the atypical neuroleptics is Zyprexa. Since there are good alternatives to these medications, they should be used first.
- As soon as you to begin anti-obsessional medication, pay particular attention to diet and an exercise program.
- If you are gaining weight on one of these medications, immediately talk to your physician about switching to another comparable drug. You may not gain weight on a similar drug. Each person has a genetically-defined set of brain receptors, and one drug may cause weight gain in one person and weight loss in another.
- If the above are not working for you, talk to your doctor about adding another medication that helps with the weight gains. Cytomel, Ritalin, nizatidine and Topamax are agents that may be useful.
- Probably the most effective tactic is to lower the dose of SSRI medication or even stop it. Many OCD patients can taper and some even stop medication. CBT causes no weight gain unless your therapist keeps candy in the waiting room.
Michael A. Jenike, MD, is Professor of Psychiatry, Harvard Medical School, Director, OCD Institute at McLean Hospital, Director, OCD Clinic at Massachusetts General Hospital, and Director, OC Foundation Scientific Advisory Board.
Julie A. Jenike, MS, CCC-SLP, is a Certified Personal Trainer and Fitness Instructor, and Certified Nutritional Consultant, Northeast Rehabilitation Network, World Gyms and Gold's Gyms.
