Olanzapine
Olanzapine (Zyprexa)
Olanzapine
((oh- LAN-zah-peen))
Pregnancy Category: C Zyprexa (Rx)

Classification: Antipsychotic agent, miscellaneous

Action/Kinetics: A thienbenzodiazepine antipsychotic believed to act by antagonizing dopamine D _1-4 and serotonin (5HT ₂) receptors. Also binds to muscarinic, histamine H _1, and alpha-1 adrenergic receptors, which can explain many of the side effects. Well absorbed from the GI tract. Peak plasma levels: 6 hr after PO dosing. Undergoes significant first-pass metabolism with about 40% metabolized before it reaches the systemic circulation. Food does not affect the rate or extent of absorption. Significantly bound to plasma proteins. Unchanged drug and metabolites are excreted through both the urine and feces.

Uses: Management of psychotic disorders. Investigational: Treatment of acute mania associated with bipolar I disorder.

Contraindications: Lactation.

Special Concerns: Use with caution in geriatric clients, as the drug may be excreted more slowly in this population. Use with caution in impaired hepatic function and in those where there is a chance of increased core body temperature (e.g., strenuous exercise, exposure to extreme heat, concomitant anticholinergic drug administration, dehydration). Due to anticholinergic side effects, use with caution in clients with significant prostatic hypertrophy, narrow-angle glaucoma, or a history of paralytic ileus. Safety and efficacy have not been determined in children less than 18 years of age.

Side Effects: Neuroleptic malignant syndrome: Hyperpyrexia, muscle rigidity, altered mental status, irregular pulse or BP, tachycardia, diaphoresis, cardiac dysrhythmia, rhabdomyolysis, acute renal failure, death. GI: Dysphagia, constipation, dry mouth, increased appetite, increased salivation, N&V, thirst, aphthous stomatitis, eructation, esophagitis, rectal incontinence, flatulence, gastritis, gastroenteritis, gingivitis, glossitis, hepatitis, melena, mouth ulceration, oral moniliasis, periodontal abscess, rectal hemorrhage tongue edema. CNS: Tardive dyskinesia, seizures, somnolence, agitation, insomnia, nervousness, hostility, dizziness, anxiety, personality disorder, akathisia, hypertonia, tremor, amnesia, impaired articulation, euphoria, stuttering, suicide abnormal gait, alcohol misuse, antisocial reaction, ataxia, CNS stimulation, coma, delirium, depersonalization, hypesthesia, hypotonia, incoordination, decreased libido, obsessive-compulsive symptoms, phobias, somatization, stimulant misuse, stupor, vertigo, withdrawal syndrome. CV: Tachycardia, orthostatic/postural hypotension, hypotension, CVA, hemorrhage, heart arrest migraine, palpitation, vasodilation, ventricular extrasystoles. Body as a whole: Headache, fever, abdominal pain, chest pain, neck rigidity, intentional injury, flu syndrome, chills, facial edema, hangover effect, malaise, moniliasis, neck pain, pelvic pain, photosensitivity. Respiratory: Rhinitis, increased cough, pharyngitis, dyspnea, apnea, asthma, epistaxis, hemoptysis, hyperventilation, voice alteration. GU: Premenstrual syndrome, hematuria, metrorrhagia, urinary incontinence, UTI, abnormal ejaculation, priapism, amenorrhea, breast pain, cystitis, decreased or increased menstruation, dysuria, female lactation, impotence, menorrhagia, polyuria, pyuria, urinary retention, urinary frequency, impaired urination, enlarged uterine fibroids. Hematologic: Leukocytosis, lymphadenopathy, thrombocytopenia. Metabolic/nutritional: Weight gain or loss, peripheral edema, lower extremity edema, dehydration, hyperglycemia, hyperkalemia, hyperuricemia, hypoglycemia, hypokalemia, hyponatremia, ketosis, water intoxication. Musculoskeletal: Joint pain, extremity pain, twitching, arthritis, back and hip pain, bursitis, leg cramps, myasthenia, rheumatoid arthritis. Dermatologic: Vesiculobullous rash, alopecia, contact dermatitis, dry skin, eczema, hirsutism, seborrhea, skin ulcer, urticaria. Ophthalmic: Amblyopia, blepharitis, corneal lesion, cataract, diplopia, dry eyes, eye hemorrhage, eye inflammation, eye pain, ocular muscle abnormality. Otic: Deafness, ear pain, tinnitus. Miscellaneous: Diabetes mellitus, goiter, cyanosis, taste perversion.

Laboratory Test Alterations: ALT, AST, GGT, alkaline phosphatase, serum prolactin, eosinophils, CPK. Hyperprolactinemia.

Overdose Management: Symptoms: Drowsiness, slurred speech. Possible obtundation, seizures, dystonic reaction of the head and neck. CV symptoms, arrhythmias. Treatment: Establish and maintain an airway and ensure adequate oxygenation and ventilation. Gastric lavage followed by activated charcoal and a laxative can be considered, although dystonic reaction may cause aspiration with induced emesis. Begin CV monitoring immediately with continuous ECG monitoring to detect possible arrhythmias. Hypotension and circulatory collapse are treated with IV fluids or sympathomimetic agents. Do not use epinephrine, dopamine, or other sympathomimetics with beta-agonist activity, as beta stimulation may worsen hypotension.

Drug Interactions: Antihypertensive agents / Antihypertensive effect Carbamazepine / Olanzepine clearance R/T metabolism CNS depressants / CNS depressant effect Levodopa and Dopamine agonists / May antagonize the effects of levodopa and dopamine agonists St. John's wort / Possible olanzapine plasma levels R/T metabolism

How Supplied: Tablet: 2.5 mg, 5 mg, 7.5 mg, 10 mg

Dosage
?Tablets Psychoses.
Adults, initial: 5-10 mg once daily without regard to meals. Goal is 10 mg daily; increments to reach 10 mg can be in 5-mg amounts but at an interval of 1 week. Doses higher than 10 mg daily are recommended only after clinical assessment and should not be greater than 20 mg/day. The recommended initial dose is 5 mg in those who are debilitated, who have a predisposition to hypotensive reactions, who may have factors that cause a slower metabolism of olanzapine (e.g., nonsmoking female clients over 65 years of age), or who may be more sensitive to the drug. It is recommended that clients who respond to the drug be continued on it at the lowest possible dose to maintain remission with periodic evaluation to determine continued need for the drug.
 Mania.
5-20 mg daily.