Bipolar disorder is a psychiatric illness that is also known as manic depression. It most commonly appears in the late teen or early adult years and is characterized by a mood state that alternates between depression and mania. Bipolar disorder may be treated by a number of medications such as lithium and valproic acid, which are known to cause weight gain due to increases in appetite and changes in carbohydrate metabolism. Fortunately, there are a number of options which are less likely to cause this troubling side effect.
Lamotrigine is a broad spectrum anticonvulsant medication used to treat a wide variety of seizure disorders and is also approved to treat bipolar disorder. Lamotrigine appears to work by stabilizing neural membranes and slowing release neurotransmitters in some areas of the brain. It is often considered to be a good alternative to the medication valproic acid which is well known to cause weight gain. Side effects of lamotrigine may include headache, nausea, dizziness and fatigue. It is also known to cause a rash in some patients, which may occasionally become severe. Any rash, along with side effects that are severe or persistent, should be reported to a physician
Carbamazepine is an older anticonvulsant medication used to treat partial seizures One form of the medication has been approved to treat bipolar disorder. It works by inhibiting rapid firing of neurons in the brain by interfering with the movement of sodium. Common side effects include stomach upset, dizziness and blurry vision. In addition, a rare but potentially fatal rash may occur along with the possibility of development of blood disorders. Occasional blood testing may be required to monitor hematologic processes, and any rash should be reported to a physician.
Oxcarbazepine, a newer chemical form of carbamazepine, is approved to treat seizure disorder and works similarly to interfere with nerve transmission by slowing the movement of sodium. Though not approved to treat bipolar disorder, according to a report published in Primary Care Companion to The Journal of Clinical Psychiatry it has been shown to be effective. Side effects may be less common than carbamazepine but may still include stomach upset, headaches and dizziness. It may also cause hyponatremia and dehydration. Skin changes, breathing difficulties or other symptoms of dehydration should be reported to a medical professional immediately.
Topiramate is another anticonvulsant that may be of some use in the treatment of bipolar disorder and, though not yet approved, is in use as an off-label medication for the disorder. It appears to work by blocking an enzyme, known as carbonic anhydrase, in the brain and by increasing acidity of the brain tissue. Topiramate is of much interest as an alternative to bipolar medications because it may actually cause weight loss in some patients. Other side effects may include changes in memory, foggy thinking, dizziness and drowsiness. Eyesight difficulties may indicate the development of glaucoma which warrants immediate medical attention.
Ziprasidone, an atypical antipsychotic, is approved to treat schizophrenia as well as bipolar disorder. The mechanism of action in the treatment of manic episodes is not well understood. Common side effects include dizziness, drowsiness, nausea and movement disorders. Pfizer, the manufacturer of ziprasidone, has reported that though some patients report weight gain, clinical studies have indicated that weight gain with ziprasidone use was not higher than that of placebo. More serious side effects may include changes in heart rhythm and the development of long term neurological damage, known as tardive dyskinesia. Patients taking ziprasidone should be monitored occasionally for the development of cardiac and neurological disorders.
- PubMed Central: Primary Care Companion to The Journal of Clinical Psychiatry, Oxcarbazepine in Bipolar Disorder
- Pfizer: Geodon Prescribing Information
- Journal of Clinical Psychiatry: Topiramate in Bipolar Disorder
- Validus Pharmaceuticals: Equetro Prescribing Information
- PsychEducation.org: Bipolar Medications and Weight Gain