About 70% of people in the United States are overweight and many of the drugs used to treat obesity-linked conditions such as diabetes, high blood pressure, and depression can cause weight gain. Patients and doctors need to be more aware of this—it's an under-recognized driver of our obesity problem. Weight gain is a possible side effect of many antidepressant drugs. While each person responds to antidepressant treatment in a different way, the following antidepressant may be more likely to cause weight gain during your treatment. Prozac is the brand name of fluoxetine, a prescription drug used to treat depression. This antidepressant is in a class of drugs known as selective serotonin reuptake inhibitors, or SSRIs. These medications work by increasing the amount of serotonin in the brain.
In addition to depression, Prozac is used to treat:
- Obsessive-compulsive disorder (OCD)
- Binge eating disorder
- Vomiting in people with moderate to severe bulimia
- Panic disorder (with or without agoraphobia, the fear of open spaces)
Why Prozac Causes Weight Gain
It is not known why Prozac causes weight gain, although it is believed that it may somehow affect a person's appetite or metabolism. It has been speculated that some people gain weight simply because they were not eating well while they were depressed and the antidepressant has caused his or her normal appetite to return.
What You Can Do to Lose Weight on Prozac
Unfortunately, there is no magic bullet to help patients lose weight gained while taking Prozac. The same options for weight loss exist as for those who have gained weight for other reasons: healthy diet, regular exercise, and weight loss drugs.
In addition, eating a high carbohydrate diet can be particularly helpful in eliminating weight gained while using antidepressants. Eating "therapeutic" amounts of carbohydrates can shut off excessive appetite by causing more serotonin to be produced.
Prozac and other antidepressants are required to carry a black box warning due to the increased risk of suicide when taking the medicine. Also, Prozac may increase suicidal thoughts or actions in children, teenagers, and young adults within the first several months of treatment or after a change in dose. You should call your doctor immediately if you have any unusual changes in behavior or mood while on Prozac, including:
- Thoughts about suicide or dying, or suicide attempts
- New or worsening depression or anxiety
- Feeling very agitated or restless
- Panic attacks
- New or worse irritability
- Acting on dangerous impulses
- Decreased need for sleep
Before taking Prozac, tell your doctor if you have a history of seizures; bipolar disorder; liver disease; heart problems, including heart rhythm problems; diabetes; glaucoma; or thoughts of suicide or attempted suicide. You may not feel the full benefits of Prozac for 4 to 6 weeks after starting the medication. If none of the above work for the patient, another option is to simply change to a different antidepressant. In addition, different people may respond in different ways to the same medication.