170 likes | 356 Views
Chapter 33. Drugs for Bipolar Disorder. Bipolar Disorder. Formerly known as manic-depressive illness Afflicts an estimated 3.7% of the adult population Mainstays of therapy Lithium, valproic acid Many also receive an antipsychotic Chronic condition that requires lifelong treatment.
E N D
Chapter 33 Drugs for Bipolar Disorder
Bipolar Disorder • Formerly known as manic-depressive illness • Afflicts an estimated 3.7% of the adult population • Mainstays of therapy • Lithium, valproic acid • Many also receive an antipsychotic • Chronic condition that requires lifelong treatment
Bipolar Disorder • Definition of bipolar disorder (BPD) • Cyclic disorder • Recurrent fluctuations in mood • Episodes of mania and depression persist for months without treatment • Treatment • Drugs • Psychotherapy
Characteristics of Bipolar Disorder • Types of mood episodes seen in bipolar disorder (BPD) • Pure manic episode (euphoric mania) • Hypomanic episode (hypomania) • Major depressive episode (depression) • Mixed episode
Patterns of Mood Episodes • Subdivided into two major categories • Bipolar I disorder • Manic or mixed episodes • Usually depressive episodes • Bipolar II disorder • Hypomanic or depressive episodes • Not manic or mixed episodes
Treatment of Bipolar Disorder • Drug therapy • Nondrug therapy
Drug Therapy • Types of drugs employed • Mood stabilizers (Lithium) • Relieve symptoms during manic and depressive episodes • Prevent recurrence of manic and depressive episodes • Do not worsen symptoms of mania or depression; do not accelerate the rate of cycling • Antipsychotics • Given during severe manic episodes • Antidepressants • Given during depressive episodes
Drug Therapy • Drug selection • Short-term therapy: manic episodes • Short-term therapy: depressive episodes • Long-term preventive treatment • Promoting compliance • Short-term hospitalization • Long-term prophylactic therapy • Education for both patient and family
Nondrug Therapy • Education • Patient and family • Psychotherapy • Individual, group, family • Electroconvulsive therapy • Last resort
Mood-Stabilizing Drugs • Lithium • Antiepileptic drugs
Lithium (Lithonate, Lithotabs) • Chemistry • Simple inorganic ion • Found naturally in animal tissues • Therapeutic uses • Bipolar disorder • Other uses • Alcoholism • Bulimia • Schizophrenia • Glucocorticoid-induced psychosis
Lithium (Lithonate, Lithotabs) • Mechanism of action • Altered distribution of certain ions • Altered synthesis and release of norepinephrine, serotonin, and dopamine • Mediates intracellular responses to neurotransmitters • Shown to facilitate regeneration of damaged optic nerves • Can increase total gray matter in regions known to atrophy in BPD
Lithium (Lithonate, Lithotabs) • Pharmacokinetics • Absorption and distribution • Excretion • Short half-life • Excreted by the kidneys • Sodium levels: lithium excretion reduced when sodium level low • Plasma levels • 0.8–1.4 mEq/L
Lithium (Lithonate, Lithotabs) • Adverse effects • Excessive lithium levels • Greater than 1.5 mEq/L • Monitor levels q 2–3 days at initiation of therapy and then q 3–6 months • Therapeutic lithium levels • Gastrointestinal • Tremors • Polyuria • Renal toxicity • Goiter and hypothyroidism • Teratogenesis
Lithium (Lithonate, Lithotabs) • Drug interactions • Diuretics • Nonsteroidal anti-inflammatory drugs (NSAIDs) • Anticholinergic drugs • Preparations, dosage, and administration • Lithium carbonate • Lithium citrate • Dosage is highly individualized
Antiepileptic Drugs • Divalproex sodium (Valproate) • Carbamazepine • Reduces symptoms • Protects against recurrence of mania and depression • Target trough plasma level: 4–12 mcg/mL • Lamotrigine • Indicated for long-term maintenance • Can be used alone or in combination
Antipsychotic Drugs in BPD • Used to acutely control symptoms during manic episodes • Used long term to help stabilize mood • Benefit patients with or without psychotic symptoms • Can be combined with mood stabilizer • Five antipsychotics approved for use • Olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal), aripiprazole (Abilify), and ziprasidone (Geodon)