Anticonvulsants. Some people with symptoms of mania who do not benefit from or would prefer to avoid lithium have been found to respond to anticonvulsant medications commonly prescribed to treat seizures.
The anticonvulsant valproic acid ( Depakote, divalproex sodium ) is the main alternative therapy for bipolar disorder. It is as effective in non-rapid-cycling bipolar disorder as lithium and appears to be superior to lithium in rapid-cycling bipolar disorder. Although valproic acid can cause gastrointestinal side effects, the incidence is low. Other adverse effects occasionally reported are headache, double vision, dizziness, anxiety, or confusion. Because in some cases valproic acid has caused liver dysfunction, liver function tests should be performed before therapy and at frequent intervals thereafter, particularly during the first 6 months of therapy.
Studies conducted in Finland in patients with epilepsy have shown that valproic acid may increase testosterone levels in teenage girls and produce polycystic ovary syndrome (POS) in women who began taking the medication before age 20. POS can cause obesity, hirsutism (body hair), and amenorrhea. Therefore, young female patients should be monitored carefully by a doctor.
Other anticonvulsants used for bipolar disorder include carbamazepine ( Tegretol ), lamotrigine ( Lamictal ), gabapentin ( Neurontin ), and topiramate ( Topamax ). The evidence for anticonvulsant effectiveness is stronger for acute mania than for long-term maintenance of bipolar disorder. Some studies suggest particular efficacy of lamotrigine in bipolar depression. At present, the lack of formal FDA approval of anticonvulsants other than valproic acid for bipolar disorder may limit insurance coverage for these medications.
Most people who have bipolar disorder take more than one medication. Along with the mood stabilizer-lithium and/or an anticonvulsant-they may take a medication for accompanying agitation, anxiety, insomnia, or depression. It is important to continue taking the mood stabilizer when taking an antidepressant because research has shown that treatment with an antidepressant alone increases the risk that the patient will switch to mania or hypomania, or develop rapid cycling. Sometimes, when a bipolar patient is not responsive to other medications, an atypical antipsychotic medication is prescribed. Finding the best possible medication, or combination of medications, is of utmost importance to the patient and requires close monitoring by a doctor and strict adherence to the recommended treatment regimen.