Seroquel® (quetiapine fumarate), and other atypical antipsychotic medications, such as Zyprexa® (olanzapine), Risperdal® (risperidone), Clozaril® (clozapine), drugs commonly prescribed for the management of schizophrenia and bipolar disorder, often have the unwanted side effect of weight gain as well as an increased risk of diabetes. Does this mean patients are forced to choose between their mental and physical health?
Why Do Atypical Antipsychotics Lead to Weight Gain?
The reason that these drugs have this unfortunate side effect is not completely understood. Dr. Hall-Flavin of the Mayo Clinic suggests that the weight gain may result from a combination of factors, including a person’s genes and the biochemical changes that occur in the brain when it is exposed to antipsychotic drugs. That would explain why some people are more susceptible to weight gain when on these medications.
Animal laboratory studies have revealed that antipsychotics increase the activity of an enzyme called AMPK, which has a role in regulating appetite. There is also the suspicion that some antipsychotic medications may impair the body's ability to use insulin (a condition called insulin resistance, which can lead to diabetes).
How to Counter Weight Gain from Antipsychotic Medication
Diet and exercise is one strategy employed to prevent weight gain when taking antipsychotic medications. Since all patients are genetically different, all are not going to have the same problem with weight gain when placed on a therapeutic antipsychotic drug. If the drug leads to a small amount of weight gain, dietary changes and increased exercise can help to prevent weight gain.
If the patient experiences a significant increase in weight, to the point of being considered obese or at risk of insulin resistance and diabetes, the psychiatrist and patent need to work together on solutions. It is certainly easy to tell someone, “just eat less and exercise more,” but making these changes can be very difficult, particularly for patients already facing mental health challenges.
For patients having weight gain issues when on antipsychotic medication, or for patients who already have difficulty with weight management, a physician or psychiatrist may be able to recommend a registered dietician and fitness program that will make it easier to plan, and stick with, healthy lifestyle changes that can help counter the medication's side effects.
Dose adjustment is another method used to prevent weight gain from antipsychotic medications.
Weight gain associated with antipsychotic drugs is, for the most part, dose dependent; meaning the higher the dose, the more weight will usually be gained. Psychiatrists will, however consider the benefits and risks of any medication, and if dose reduction seems appropriate, the doctor may slowly and marginally reduce that dose to the minimum level required for management of symptoms. Never reduce or stop taking prescribed medication without physician approval.
More Information on Antipsychotics and Weight Management
To learn more about the side effects of antipsychotic drugs, first carefully look at the specific prescribing information (PI) of the medication in question. The PI is included with all prescriptions, and can also be found online by going to the website of the company that manufactures or distributes the drug.
Another helpful resource is a recent scientific paper reviewing studies that have examined the most common side effects of atypical antipsychotics: Ucok A, and Gaebel, W. (2008). "Side effects of atypical antipsychotics." World Psychiatry, 7 (1).
Please note: The information in this article is not to be followed as medical advice, diagnosis or treatment. Please consult with your physician or primary health practitioner for information regarding your own personal health and necessary treatments.
Tami Port - Tami Port is a college professor of cell and microbiology and creator of ScienceProfOnline.com, a free science education website.
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