GEO (marketed as Geodon, Zeldox) was the fifth atypical antipsychotic to gain FDA approval (February 2001). GEO is Food and Drug Administration (FDA) approved for the treatment of schizophrenia, and the intramuscular injection form of ziprasidone is approved for acute agitation in schizophrenic patients. GEO has also received approval for acute treatment of mania associated with bipolar disorder. .

Medicinal name:
  • Ziprasidone 60 MG Oral Capsule [Geodon]
  • Ziprasidone 80 MG Oral Capsule [Geodon]
  • Ziprasidone 40 MG Oral Capsule [Geodon]
  • Ziprasidone 20 MG Oral Capsule [Geodon]
  • Carbenicillin 382 MG Oral Tablet [Geocillin]

GEO - Pharmacology:

The mechanism of action of GEO, as with other drugs used to treat schizophrenia, is unknown. GEO exhibited high in vitro binding affinity for the dopamine D2 and D3, the serotonin 5HT2A, 5HT2C, 5HT1A, 5HT1D and alpha 1-adrenergic receptors, and moderate affinity for the histamine H1 receptor. However, it has been proposed that the drug's therapeutic activity in schizophrenia is mediated through a combination of dopamine Type 2 (D2) and serotonin Type 2 (5HT2) receptor antagonism.

GEO for patients

GEO is an antipsychotic medicine, and used to treat schizophrenia. Patients may experience the following symptoms or signs:

  • hearing voices, seeing things, or sensing things that are not actually there
  • unusual suspiciousness
  • having false beliefs
  • becoming withdrawn

If the patent has heart problems, discuss with doctor before taking GEO. GEO can cause dizziness, sleepness, use with caution when driving, operating machinery. Avoid alcohol while taking GEO.

Contact your doctor if you experience any unusual symptomes or signs, or start taking a new medication (including prescription and non-prescription medicines)

GEO Interactions

Drug-drug interactions can be pharmacodynamic (combined pharmacologic effects) or pharmacokinetic (alteration of plasma levels). The risks of using ziprasidone in combination with other drugs have been evaluated as described below. Based upon the pharmacodynamic and pharmacokinetic profile of ziprasidone, possible interactions could be anticipated:

Pharmacodynamic Interactions

  1. GEO should not be used with any drug that prolongs the QT interval .
  2. Given the primary CNS effects of ziprasidone, caution should be used when it is taken in combination with other centrally acting drugs.
  3. Because of its potential for inducing hypotension, ziprasidone may enhance the effects of certain antihypertensive agents.
  4. GEO may antagonize the effects of levodopa and dopamine agonists.

Pharmacokinetic Interactions

The Effect of Other Drugs on GEO

Carbamazepine Carbamazepine is an inducer of CYP3A4; administration of 200 mg BID for 21 days resulted in a decrease of approximately 35% in the AUC of ziprasidone. This effect may be greater when higher doses of carbamazepine are administered.

Ketoconazole Ketoconazole, a potent inhibitor of CYP3A4, at a dose of 400 mg QD for 5 days, increased the AUC and C max of ziprasidone by about 35-40%. Other inhibitors of CYP3A4 would be expected to have similar effects.

Cimetidine Cimetidine at a dose of 800 mg QD for 2 days did not affect ziprasidone pharmacokinetics.

Antacid The coadministration of 30 mL of MAALOX with ziprasidone did not affect the pharmacokinetics of ziprasidone.

In addition, population pharmacokinetic analysis of schizophrenic patients enrolled in controlled clinical trials has not revealed evidence of any clinically significant pharmacokinetic interactions with benztropine, propranolol, or lorazepam.

Effect of GEO on Other Drugs

In vitro studies revealed little potential for ziprasidone to interfere with the metabolism of drugs cleared primarily by CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, and little potential for drug interactions with ziprasidone due to displacement.

Lithium GEO at a dose of 40 mg BID administered concomitantly with lithium at a dose of 450 mg BID for 7 days did not affect the steady-state level or renal clearance of lithium.

Oral Contraceptives GEO at a dose of 20 mg BID did not affect the pharmacokinetics of concomitantly administered oral contraceptives, ethinylestradiol (0.03 mg) and levonorgestrel (0.15 mg).

Dextromethorphan Consistent with in vitro results, a study in normal healthy volunteers showed that ziprasidone did not alter the metabolism of dextromethorphan, a CYP2D6 model substrate, to its major metabolite, dextrorphan. There was no statistically significant change in the urinary dextromethorphan/dextrorphan ratio.

GEO Contraindications

QT Prolongation

Because of ziprasidoneís dose-related prolongation of the QT interval and the known association of fatal arrhythmias with QT prolongation by some other drugs, ziprasidone is contraindicated in patients with a known history of QT prolongation (including congenital long QT syndrome), with recent acute myocardial infarction, or with uncompensated heart failure.

Pharmacokinetic/pharmacodynamic studies between ziprasidone and other drugs that prolong the QT interval have not been performed. An additive effect of ziprasidone and other drugs that prolong the QT interval cannot be excluded. Therefore, ziprasidone should not be given with dofetilide, sotalol, quinidine, other Class Ia and III anti-arrhythmics, mesoridazine, thioridazine, chlorpromazine, droperidol, pimozide, sparfloxacin, gatifloxacin, moxifloxacin, halofantrine, mefloquine, pentamidine, arsenic trioxide, levomethadyl acetate, dolasetron mesylate, probucol or tacrolimus. GEO is also contraindicated with drugs that have demonstrated QT prolongation as one of their pharmacodynamic effects and have this effect described in the full prescribing information as a contraindication or a boxed or bolded warning.


GEO is contraindicated in individuals with a known hypersensitivity to the product.


Manufacturers name:

  • Cardinal Health
  • Rebel Distributors Corp
  • Roerig
  • Unit Dose Services
  • State of Florida DOH Central Pharmacy
  • Lake Erie Medical & Surgical Supply DBA Quality Care Products LLC
  • Lake Erie Medical DBA Quality Care Products LLC

Generic name, Overdose, Half Life GEO, Food Interactions, Chemical, etc..

GEO see also Hibiscus flowers

Brand Names containing Ziprasidone