Special Populations

Assessment and management by appropriate psychiatric specialists is important for special populations such as pediatrics, geriatrics, pregnancy, and others.

Pediatrics

Evidence regarding treatment of bipolar disorder in children and adolescents is more limited than in adults. Children and adolescents appear to be particularly sensitive to medication side effects. With these caveats, an increasing body of evidence supports the use of mood stabilizing drugs and atypical antipsychotic drugs in children and adolescents with bipolar disorder. Lithium is FDA approved for treatment of bipolar disorder in children and adolescents as young as age 12. Aripiprazole and risperidone are FDA approved in children and adolescents as young as age 10. The guidelines additionally support DVP, carbamazepine, olanzapine, quetiapine, and risperidone.49

Initial dosages of drug therapy in the pediatric population are lower than in adults. Metabolic elimination rates of many drugs are increased in children, however, so they may actually require higher dosages on a weight-adjusted basis. Dosages are titrated carefully according to response and tolerability. For lithium, DVP, and carbamazepine, serum concentration monitoring is recommended as a guide to dosage adjustment and minimizing adverse effects.

Children and adolescent patients are often more sensitive to drug side effects than adults. In particular, they are likely to experience significant weight gain due to atypical antipsychotic drugs.50 Cognitive toxicity, manifested as confusion, memory or concentration impairment, or impaired learning, is often difficult to detect and is a special consideration in the pediatric population so that intellectual and educational development is not hindered by drug therapy.

Comorbid conditions must be addressed in order to maximize desired outcomes. For comorbid bipolar disorder and attention deficit hyperactivity disorder when stimulant therapy is indicated, treatment of mania is recommended before starting the stimulant in order to avoid exacerbation of mood symptoms by the stimulant.

Geriatrics

Treatment of elderly patients with bipolar disorder requires special care because of increased risks associated with concurrent medical conditions and drug-drug interactions. General medical conditions including endocrine, metabolic, or infectious diseases can mimic mood disorders. Patients should be evaluated for such medical ill nesses that may cause or worsen mood symptoms. As physiologic systems change with aging, elimination of drugs is often slowed. Examples are slowed renal elimination of lithium and slowed hepatic metabolism of carbamazepine and VPA. As a result, dosages of drugs required for therapeutic effect are generally lower in geriatric patients. Also, changes in membrane permeability with aging increase risk of CNS side effects. Increased frequency of patient monitoring is often required, including serum drug concentration monitoring.

Vigilance for drug-drug interactions is required because of the greater number of medications prescribed to elderly patients and enhanced sensitivity to adverse effects. Pharmacokinetic interactions include metabolic enzyme induction or inhibition and protein binding displacement interactions, for example, DVP and warfarin. Phar-macodynamic interactions include additive sedation and cognitive toxicity, which increase risk of falls and other impairments.

Pregnancy and Postpartum

Treatment of bipolar disorder during pregnancy is fraught with controversy and conflicting recommendations. The key issue is the relative risk of teratogenicity with drug use during pregnancy versus risk of bipolar relapse without treatment with consequent potential harm to both the pregnant patient and the fetus. Therapeutic judgments depend on the history of the patient and whether the pregnancy is planned or unplanned. Treatment is best managed when the pregnancy is planned. Clinicians should discuss the issue with every patient with bipolar disorder who is of childbearing potential. A pregnancy test should be obtained prior to initiating drug therapy. For a patient with severe bipolar disorder, a history of multiple mood episodes, rapid cycling, or suicide attempts, discontinuing treatment, even for a planned pregnancy, is unwise. For a patient with a remote history of a single mood episode with subsequent long stability and who is contemplating pregnancy, the answer is less clear. Patients should be provided clear and reliable information about risks versus benefits of stopping or continuing therapy in order to make an informed decision. Patients who decide to discontinue drug therapy prior to pregnancy should taper medications slowly in order to reduce risk of relapse.51

Lithium administration during the first trimester is associated with Ebstein's anomaly in the infant, a downward displacement of the tricuspid valve into the right ventricle. Although more likely to occur in children of patients who took lithium during pregnancy, the absolute risk is considered small, around 0.1%. Pharmacokinetic handling of lithium changes as pregnancy progresses. Renal lithium clearance increases, which requires a dosage increase to maintain a therapeutic serum concentration. It may be advisable to decrease or discontinue lithium at term or the onset of labor to

avoid toxicity postpartum when there is a large reduction in fluid volume.

Lithium can cause hypotonicity and cyanosis in the neonate, usually termed the "floppy baby" syndrome. Most data indicate normal neurobehavioral development once these symptoms resolve. Lithium is readily transferred via breast milk. Breastfeeding is not advised for patients who are taking lithium.28

VPA and carbamazepine are human teratogens. Neural tube defects such as spina bifida occur in up to 9% of infants exposed during the first trimester. The risk of neural tube defects is related to exposure during the third and fourth weeks following conception. As such, women with unplanned pregnancies may not know they are pregnant until after the risk of exposure has occurred. Carbamazepine can cause fetal vitamin K deficiency. Vitamin K is important for facial growth and for clotting factors. Risk of facial abnormalities is increased with carbamazepine and VPA, and neonatal bleeding is increased in infants of mothers who are treated with carbamazepine during pregnancy.51,52

Less data are available on other anticonvulsant mood stabilizing drugs. Lamotri-

gine may be associated with an increased risk of oral clefts in association with first 51

trimester exposure.

Conventional antipsychotic drugs have been available for many years, and more data are available on their use in pregnancy compared to atypical antipsychotic drugs, but treatment guidelines for bipolar disorder do not otherwise support conventional antipsychotics as an initial choice in treatment.

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BiPolar Explained

BiPolar Explained

Bipolar is a condition that wreaks havoc on those that it affects. If you suffer from Bipolar, chances are that your family suffers right with you. No matter if you are that family member trying to learn to cope or you are the person that has been diagnosed, there is hope out there.

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