The Pharmacist's Guide to Bipolar Disorder

Bipolar disorder, also referred to as manic?depressive illness, is a serious mental condition that causes unpredictable and erratic changes in an individual's energy level, temperament, mood, thought process, and ability to function in everyday life. The dramatic changes in behavior are very different from the everyday ups and downs of life and can greatly affect both the social and physical aspects of one's life. Some people with bipolar disorder may even resort to suicide. With the proper treatment intervention, however, most patients with this disorder can lead relatively normal and productive lives.

Approximately 2.3 million individuals in the United States over the age of 18 suffer from bipolar disorder.¹ This disorder normally manifests itself in late adolescence or early adulthood. It is equally common among men and women. People may have symptoms for many years before being diagnosed. The condition is considered to be a long-term illness that must be treated throughout the patient's life.

Types of Bipolar Disorder

The typical form of bipolar disorder that is characterized by recurring episodes of mania and depression is called bipolar I disorder. In some cases, individuals may never experience episodes of severe mania and may experience only mild stages of mania, along with episodes of depression. This type is called bipolar II disorder. When a person experiences 4 or more episodes of mania and depression within a 12-month period, this is termed rapid-cycling bipolar disorder. In the rapid-cycling type, these episodes can occur sometimes within weeks of each other, or several months apart.

Causes of Bipolar Disorder

The exact cause of bipolar disorder is undetermined, but researchers are continually learning more about this disorder. Several genetic, physiologic, and environmental factors may be responsible for triggering episodes among manic?depressive patients. Chronic stress or recurring episodes of depression also can be considered risk factors. Certain conditions?such as thyroid abnormalities, vitamin B ₁₂ deficiency, and epilepsy?and medications such as steroids, stimulants, and hallucinogens can trigger episodes in some individuals.

Signs and Symptoms of Bipolar Disorder

Bipolar disorder is typically characterized by dramatic changes in behavior ranging from euphoric highs, or "mania" episodes (Table 1), to lows, referred to as "depressive" episodes (Table 2). The intensity of these episodes varies from patient to patient. The onset of an episode is manifested in 1 of 2 ways:

• Dramatic mood swings (feelings of elation to hopelessness)
• Extreme alteration in energy levels and behaviors

Not all individuals with bipolar disorder will experience the same signs or symptoms. Some people will experience some of the more severe symptoms, whereas others may experience hypomania, which is a mild form of mania in which nothing really appears wrong. If left untreated, hypomania can become severe mania or even depression. Some patients experience episodes of psychosis, which include delusions. In severe cases, some patients may ponder or attempt suicide. These people require immediate medical/psychiatric attention.

Diagnosis

Like most psychological disorders, there are no diagnostic tests to determine whether a person is bipolar. Diagnosis generally is made through a mental assessment of the patient directly, or indirectly from family members. Individuals with bipolar disorder often have abnormal thyroid function. Disturbances in the thyroid function can lead to mood and energy changes. Therefore, it is imperative that thyroid levels be monitored routinely in bipolar patients. In some cases, thyroid supplementation may be necessary.

Pharmacologic Treatment

The primary goal of all bipolar therapy is remission from episodes of mania and depression to enable the patient to lead a functional life. The first line of defense in treating bipolar disorder is pharmacologic intervention. Medications generally are prescribed specifically for the treatment of both manic and depressive episodes. Currently, several medications are used to treat bipolar episodes.

Mood-Stabilizing Agents

Lithium

In 1970, the FDA approved lithium as the drug of choice for the treatment of mania in bipolar disorder. Lithium alters the cation transport across the cell membrane in nerve and muscle cells and influences the reuptake of serotonin and/or norepinephrine.² Doses of 900 to 2400 mg per day usually are given in 3 to 4 divided doses, or 900 to 1800 mg per day (extended release) every 12 hours. Serum levels should be monitored every 4 to 5 days during initial therapy and then twice a week until they become stable. Lithium may cause hypothyroidism, so levels should be monitored periodically and supplements prescribed if necessary. The most frequent adverse effects include polyuria, nausea, polydipsia, and fine tremors. Long-term use of lithium can affect renal function, so it should have periodic monitoring as well.

Anticonvulsants

In 1995, divalproex sodium became the first anticonvulsant to be approved by the FDA for the treatment of bipolar disorder. The exact therapeutic action in treating this disorder is not known, but it may be attributed to GABAergic mechanisms.³ In 2003, lamotrigine became the second anticonvulsant to be approved by the FDA for this indication.⁴ Other anticonvulsants?such as carbamazepine, gabapentin, and topiramate?also are used in some cases. Anticonvulsants may be used in conjunction with lithium. Common adverse effects include gastrointestinal effects, menstrual irregularities in women, headaches, and tinnitus. Hepatic function and complete blood count should be monitored routinely.

Miscellaneous Agents

Antipsychotics

Acute episodes of mania may be accompanied by some psychosis. Therefore, antipsychotics may be prescribed. Olanzapine is the first antipsychotic to be approved by the FDA for the treatment of bipolar disorder. Risperidone and clozapine also are commonly prescribed. Other antipsychotics are being studied to determine whether they would be beneficial in treating bipolar disorder. Physicians often prescribe benzodiazepines to treat insomnia or sleep disorders, which frequently accompany bipolar disorder. It is recommended that these agents not be used long term because of the addictive effects.

Antidepressants

Antidepressants, such as tricyclics and serotonin reuptake inhibitors, sometimes are prescribed during depressive episodes. They can trigger mania, however, so usage is limited or reserved until after an individual is receiving a therapeutic dose of lithium or another mood-stabilizing agent.

Conclusion

Bipolar disorder is a life-long condition, but patients can find hope in knowing that they can be effectively treated with the use of medications and counseling. Self-help support groups are strong allies for bipolar patients. Individuals who have support systems in conjunction with proper treatment tend to have fewer episodes. Early intervention can help people lead a normal life. At times, changes in treatment plans are warranted, based on patient response, medical conditions, or occurrence of adverse effects.

If not treated, bipolar disorder can become very serious and can even result in death or suicide through risky or reckless behavior. The pharmacist also can be an ally in providing patient education, by stressing the importance of medication compliance.

Ms. Terrie is a clinical pharmacy writer based in Slidell, La.

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