ziprasidone hydrochloride

ziprasidone hydrochloride

Geodon

Pharmacologic class: Benzisoxazole derivative

Therapeutic class: Antipsychotic

Pregnancy risk category C

FDA Boxed Warning

• Elderly patients with dementia-related psychosis are at increased risk for death. Although causes of death varied, most appeared to be cardiovascular or infectious.
• Drug isn't approved for treatment of dementia-related psychosis.

Action

Unknown. Thought to antagonize dopamine₂ and serotonin₂ receptors.

Availability

Capsules: 20 mg, 40 mg, 60 mg, 80 mg

Injection: 20 mg/ml

⊘Indications and dosages

➣ Schizophrenia

Adults: Initially, 20 mg P.O. b.i.d. with food; may increase q 2 days up to 80 mg b.i.d. Usual maintenance dosage is 20 to 80 mg P.O. b.i.d.; maximum recommended dosage is 80 mg b.i.d. For prompt control of acute agitation, 10 to 20 mg I.M. as a single dose; depending on patient's response, may repeat 10-mg I.M. dose q 2 hours or 20-mg I.M. dose q 4 hours to a maximum daily dosage of 40 mg.

Contraindications

• Hypersensitivity to drug
• History of arrhythmias, prolonged QT interval
• Recent myocardial infarction
• Uncompensated heart failure
• Concomitant use of arsenic trioxide, chlorpromazine, class IA or III antiarrhythmics, or other drugs that prolong the QT interval

Precautions

Use cautiously in:
• cardiovascular disorders, dysphagia, hyperprolactinemia, bradycardia, hypokalemia, hypomagnesemia
• adverse reactions with previous use of atypical antipsychotics (such as risperidone or clozapine)
• pregnant patients.

Administration

• Give with food.
• Know that P.O. therapy should replace I.M. therapy as soon as possible.
• Don't give with drugs that prolong the QT interval.

Route	Onset	Peak	Duration
P.O.	Several hr	1-3 days	Unknown
I.M.	Unknown	1 hr	Unknown

Adverse reactions

CNS: dizziness, drowsiness, dystonia, hypertonia, asthenia, akathisia, extrapyramidal reactions, agitation, headache, insomnia, personality disorder, paresthesia, speech disorder, neuroleptic malignant syndrome, seizures, suicide attempt

CV: orthostatic hypotension, hypertension, tachycardia, arrhythmias (from prolonged QT interval)

EENT: abnormal vision, rhinitis

GI: nausea, vomiting, diarrhea, constipation, dyspepsia, dry mouth, anorexia

GU: dysmenorrhea, priapism

Musculoskeletal: myalgia

Respiratory: cough, cold symptoms

Skin: urticaria, rash, fungal dermatitis, diaphoresis, photosensitivity

Other: accidental injury, pain at I.M. injection site

Interactions

Drug-drug. Antihypertensives: additive hypotension

Carbamazepine: decreased ziprasidone blood level

Centrally acting drugs: additive CNS effects

Dopamine agonists, levodopa: antagonism of these drugs' effects

Drugs that decrease potassium or magnesium level (such as diuretics) or prolong QT interval (such as dofetilide, moxifloxacin, pimozide, quinidine, sotalol, sparfloxacin, thioridazine): increased risk of arrhythmias

Ketoconazole: increased ziprasidone blood level

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

Patient monitoring

• Monitor ECG before and during therapy. Stay alert for prolonged QT interval.
• Assess blood pressure for hypertension and orthostatic hypotension.
☞ Monitor neurologic status, especially for and neuroleptic malignant syndrome.
☞ Watch for adverse reactions. Know that dizziness, syncope, or palpitations may signify life-threatening arrhythmias caused by prolonged QT interval.
☞ Be aware that patient with bradycardia, hypokalemia, or hypomagnesemia is at greater risk for torsades de pointes and sudden death.

Patient teaching

• Tell patient to take with food.
• Explain therapy and need for follow-up laboratory testing.
☞ Advise patient to promptly report fainting, seizures, high fever, sweating, unstable blood pressure, stupor, muscle rigidity, or suspected infection.
• Instruct patient to consult prescriber before taking over-the-counter preparations.
• Caution patient to avoid driving and other hazardous activities until drug effects are known.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure drop.
• Advise patient to avoid sun exposure and to wear sunscreen and protective clothing when going outdoors.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and herbs mentioned above.